PRC-150?

[Baconcane]

Need to know a little about using the NVIS antenna with the 150?...have the 150 but no amplifier according to what I read it calms to work without amplifier for 200km, any info would help me in hurricane exercises.

[The Reaper]

Need to know a little about using the NVIS antenna with the 150?...have the 150 but no amplifier according to what I read it calms to work without amplifier for 200km, any info would help me in hurricane exercises.

Was 15 days not long enough for you to read your registration message and comply with the process before posting?

TR

[glebo]

DOnt know off the top of my head what the power output is on a 150. But, if your using the AS-2259 NVIS that came with the prc104, you can get 0-500 miles out of 20 watts. You can also use a 1/4 wave high doublet. (which is pretty much omni-directional for short range). Of course that depends....on how good your freq manager is at selecting the propagated freq's for the time periods that you want to make your shot. Bottom line....you dont need no stinkin' AMPLIFYER!!

[Amato]

Another question to throw onto the 150 subject, can it use SOF ALE or just Mil Standard?

[glebo]

no, the 150 is MIL STD ALE. (Narrows your ALE capability and again, relies on the proficiency of a freq manager) I believe the only radio that we have to do SOF ALE is the 137

[Amato]

Thank you for the clarification.

[DarkWatch]

Need to know a little about using the NVIS antenna with the 150?...have the 150 but no amplifier according to what I read it calms to work without amplifier for 200km, any info would help me in hurricane exercises.

You have no problem with the 150 for NIVIS. Don't need an amp. Just a good antenna. Hell, I talked voice to Sigonella Italy on voice 5X with a dipole and no amp.

Cut a dipole to freq and mount it about 6 feet above the ground (broad side to the receiving station) for NIVIS. Raise or lower it to adjust QRK.

When in doubt...call the SMRS guys.

[LongWire]

Damn, I hadnt heard anything about this............Looks like its a good system. Harris makes solid stuff!!!!!

[bravo22b]

I am trying to get myself educated on the PRC-150, and HF commo in general. I have already read what I can find on the site, and I have downloaded a bunch of reference material, to include:


USMC Antenna Handbook
FM 6-02.53 Tactical Radio Operations
An article titled: "OPERATIONAL CONCEPT AND PROCEDURES FOR HF RADIO IN THE BRIGADE COMBAT TEAMS"
An article titled: "AN/PRC-150 HF radio in urban combat"


I have some familiarity with the basic operation of the radio, and have used one successfully in ALE mode this past summer in what I am assuming was ground wave transmission, 5-15 km distance. I am mostly interested in information regarding manpack use for a LRS team, with an eye towards simplicity, ease of use, and minimizing the amount of equipment needed. After all, I will be trying to teach this to my E-3 and E-4 11B's who aren't likely to remember much about antenna theory, but will need to know how to turn the radio on, and make commo. I am also guessing, perhaps incorrectly, that we will be using them mostly for short-medium range commo for the foreseeable future (in training). I am sure I will get some good stuff when I go to RSLC in June, but I like to be prepared.

I have made a first pass at reading through the material, and I have a few questions I am sure someone here can help answer.

FM 6-02.53 talks about using the 10 ft whip as a field expedient NVIS antenna by turning the radio on its side and supporting the end of the whip with an insulator. I have also read about using ground radials to improve the performance of vertical antennas. Will ground radials also help increase the efficiency of the whip when used horizontally as an improvised NVIS antenna, or is the effect lost? And is there any other field expedient that can help increase the efficiency of the whip when used like this?

Also, I am trying to find out if there is any kind of quick reference card for using the 150, something that has the basic programming/usage steps and other basic info like antenna formulas on a GTA card. I have thought about trying to make one myself, but if there is already one out there, it will probably be better than whatever I come up with.

Any information (like a reference card) that has OPSEC issues can be sent to me at my .mil email, which I can PM as necessary.

Thanks in advance.

[Ret10Echo]

I am trying to get myself educated on the PRC-150, and HF commo in general. I have already read what I can find on the site, and I have downloaded a bunch of reference material, to include:


USMC Antenna Handbook
FM 6-02.53 Tactical Radio Operations
An article titled: "OPERATIONAL CONCEPT AND PROCEDURES FOR HF RADIO IN THE BRIGADE COMBAT TEAMS"
An article titled: "AN/PRC-150 HF radio in urban combat"


I have some familiarity with the basic operation of the radio, and have used one successfully in ALE mode this past summer in what I am assuming was ground wave transmission, 5-15 km distance. I am mostly interested in information regarding manpack use for a LRS team, with an eye towards simplicity, ease of use, and minimizing the amount of equipment needed. After all, I will be trying to teach this to my E-3 and E-4 11B's who aren't likely to remember much about antenna theory, but will need to know how to turn the radio on, and make commo. I am also guessing, perhaps incorrectly, that we will be using them mostly for short-medium range commo for the foreseeable future (in training). I am sure I will get some good stuff when I go to RSLC in June, but I like to be prepared.

I have made a first pass at reading through the material, and I have a few questions I am sure someone here can help answer.

FM 6-02.53 talks about using the 10 ft whip as a field expedient NVIS antenna by turning the radio on its side and supporting the end of the whip with an insulator. I have also read about using ground radials to improve the performance of vertical antennas. Will ground radials also help increase the efficiency of the whip when used horizontally as an improvised NVIS antenna, or is the effect lost? And is there any other field expedient that can help increase the efficiency of the whip when used like this?

Also, I am trying to find out if there is any kind of quick reference card for using the 150, something that has the basic programming/usage steps and other basic info like antenna formulas on a GTA card. I have thought about trying to make one myself, but if there is already one out there, it will probably be better than whatever I come up with.

Any information (like a reference card) that has OPSEC issues can be sent to me at my .mil email, which I can PM as necessary.

Thanks in advance.

Bravo22...

The characteristic you are talking about for a NVIS effect off the whip is simply changing the orientation of the main lobe. I am sure you have seen diagrams showing how the waves propagate off of the whip. The image usually looks like a large doughnut with the whip in the center. The gap being directly off of the tip of the antenna. Laying the doughnut on its side gives you a vertical radiation which can assist in a NVIS effect. Of course use of a ground may be required in order to really achieve the takeoff angle you are looking for.

Using a counterpoise is helpful in situations where earth-ground is not conducive to the takeoff angle you wish to achieve. Of course all of this is dependent upon proper frequency selection in order to achieve the near-vertical bounce you are looking for. For that reason, NVIS operations tend to be the area where everyone's lunch gets eaten, particularly in that area where the ground wave and sky wave may cause some fading.

If you can not find an instruction card or cheater that someone else has made, simply work the step by step yourself and write it down as you are doing it. When you are done have someone else use only the card and determine if the end result is the same. It should give you something pretty handy as well as something that is tailored specifically to your needs.

Have fun.

R10

[bravo22b]

The characteristic you are talking about for a NVIS effect off the whip is simply changing the orientation of the main lobe. I am sure you have seen diagrams showing how the waves propagate off of the whip. The image usually looks like a large doughnut with the whip in the center. The gap being directly off of the tip of the antenna. Laying the doughnut on its side gives you a vertical radiation which can assist in a NVIS effect. Of course use of a ground may be required in order to really achieve the takeoff angle you are looking for.

Using a counterpoise is helpful in situations where earth-ground is not conducive to the takeoff angle you wish to achieve. Of course all of this is dependent upon proper frequency selection in order to achieve the near-vertical bounce you are looking for. For that reason, NVIS operations tend to be the area where everyone's lunch gets eaten, particularly in that area where the ground wave and sky wave may cause some fading.


Thanks for the reply. I am going to to try to read back what you said in 11B language to make sure I understand.

The radio set comes with a small ground rod and a length of braided copper. My understanding is that this should always be used when practical, but I also understand that while better than nothing, this may or may not be a very suitable ground. In cases when there is a little more time and/or space to get set up, ground radials may help what otherwise might not be a very good ground through the grounding rod, and should help performance of the antenna somewhat. Is it correct that this effect is regardless of the orientation of the antenna?

I guess in my mind I am trying to sort out a logical sequence for trying to establish HF (short-medium range) with the least amount of time and setup. Here is what I am thinking, maybe the fine gentlemen here can tell me if this makes sense.


On the move - radio in ruck, whip antenna, no ground other than a grounding tail (mentioned in some of the above referenced articles)
At a brief halt - radio stays in ruck, whip antenna, deploy single ground rod
Long halt / Hide site - radio out of ruck, whip antenna, grounding radials
Long halt / Hide site - radio out of ruck, RF-1941 antenna or field expedient antenna if can't make commo with long whip


Frequency selection will be out of my control, but my assumption in this scenario is using ALE mode where hopefully at least some of the freqs are suitable for NVIS.

And I think I understand about ground wave/sky wave interference - the basic idea being that in the zone where the receiving station gets both signals, they may have a canceling effect.

[69harley]

HF NVIS comms is not for walking around. That might work for other CNRs, but not HF NVIS.

[Ret10Echo]

Thanks for the reply. I am going to to try to read back what you said in 11B language to make sure I understand.

The radio set comes with a small ground rod and a length of braided copper. My understanding is that this should always be used when practical, but I also understand that while better than nothing, this may or may not be a very suitable ground. In cases when there is a little more time and/or space to get set up, ground radials may help what otherwise might not be a very good ground through the grounding rod, and should help performance of the antenna somewhat. Is it correct that this effect is regardless of the orientation of the antenna?

***What you should understand is what is meant by “ground”. In the context of this discussion ground has more to do with the conductivity of the soil or surface below your radio. Not to get too in the weeds, but what must be understood is the waves coming off the antenna travel in both directions, up and down (picture that same doughnut buried halfway into the ground). Ideally the waves bouncing off the “ground” will meet the free-space (sky) waves in-phase and help things along. This ground is not necessarily the surface which you are walking on, and will vary based upon soil composition. Some places are better than others. Dry sand soil is generally a poor ground so a counterpoise (artificial ground) is appropriate. So a grounding rod is probably not exactly what we are talking about. Would it help? …sure…is it practical?....No. A counterpoise presents the best solution to get the waves to have as vertical a takeoff angle as possible and increase the gain of those waves. (hope I didn’t geek out too much on that)


I guess in my mind I am trying to sort out a logical sequence for trying to establish HF (short-medium range) with the least amount of time and setup. Here is what I am thinking, maybe the fine gentlemen here can tell me if this makes sense.

1. On the move - radio in ruck, whip antenna, no ground other than a grounding tail (mentioned in some of the above referenced articles)

***NVIS while moving is somewhat problematic. The reliability would not be the best, and I personally would not count on it. Ground wave maybe, but there are always possibilities. The simplest solution may be using a wire of appropriate length and having someone stretch it out for you (use an insulated stick or something to avoid burning you buddy) Depending upon the situation and circumstances you may be able to get a bit more creative on how you deploy your antenna. The biggest thing is to work this out beforehand since you may find that the solutions are impractical.

2. At a brief halt - radio stays in ruck, whip antenna, deploy single ground rod
3. Long halt / Hide site - radio out of ruck, whip antenna, grounding radials
4. Long halt / Hide site - radio out of ruck, RF-1941 antenna or field expedient antenna if can't make commo with long whip

***I am personally a fan of a wire antenna. They tend to be more durable and less of a “signature”. A long whip is a bit annoying while you are moving (I am sure you realize), but if I can chuck out a wire and use a Low-to-the-ground Dipole , inverted ‘L’ or an Inverted ‘V’ I find it much easier. A wire antenna can also be configured to fit the physical characteristics of where you are. A long whip is a long whip so you have to make it fit. (Example: Inverted L consisted of wire off the radio and run through a 550 cord loop about 3 feet above the radio, wire run out about 15 feet and secured)

Frequency selection will be out of my control, but my assumption in this scenario is using ALE mode where hopefully at least some of the freqs are suitable for NVIS.

***Your spectrum manager should have an understanding of what the requirements are and provide you with appropriate frequencies. It helps to double check the numbers for sanity purposes. There are several prop models and other resources on the web you can use to give yourself a warm fuzzy.

And I think I understand about ground wave/sky wave interference - the basic idea being that in the zone where the receiving station gets both signals, they may have a canceling effect.
**Yup

I know there are some Commo-Hammies wandering the hallways here that may have some additional ideas. (Albeham where are you?) Trying to keep it at the appropriate language level. Here is a manual you may find useful. It is comparable to the Single Channel Radio Techniques FM. I figure if it is written for Marines it should be pretty straightforward.

http://www.armymars.net/ArmyMARS/Antennas/Resources/usmc-antenna-hb.pdf



R10

[bravo22b]

***What you should understand is what is meant by “ground”. In the context of this discussion ground has more to do with the conductivity of the soil or surface below your radio. Not to get too in the weeds, but what must be understood is the waves coming off the antenna travel in both directions, up and down (picture that same doughnut buried halfway into the ground). Ideally the waves bouncing off the “ground” will meet the free-space (sky) waves in-phase and help things along. This ground is not necessarily the surface which you are walking on, and will vary based upon soil composition. Some places are better than others. Dry sand soil is generally a poor ground so a counterpoise (artificial ground) is appropriate. So a grounding rod is probably not exactly what we are talking about. Would it help? …sure…is it practical?....No. A counterpoise presents the best solution to get the waves to have as vertical a takeoff angle as possible and increase the gain of those waves. (hope I didn’t geek out too much on that)


That helps, thank you. I know just enough about electrical grounding to be dangerous, but this makes sense to me. I do know enough to know that the ground rod that comes with the radio (about 16" long or so) isn't going to do a whole lot anyway, especially in rocky/sandy soil.

***NVIS while moving is somewhat problematic. The reliability would not be the best, and I personally would not count on it. Ground wave maybe, but there are always possibilities. The simplest solution may be using a wire of appropriate length and having someone stretch it out for you (use an insulated stick or something to avoid burning you buddy) Depending upon the situation and circumstances you may be able to get a bit more creative on how you deploy your antenna. The biggest thing is to work this out beforehand since you may find that the solutions are impractical.

***I am personally a fan of a wire antenna. They tend to be more durable and less of a “signature”. A long whip is a bit annoying while you are moving (I am sure you realize), but if I can chuck out a wire and use a Low-to-the-ground Dipole , inverted ‘L’ or an Inverted ‘V’ I find it much easier. A wire antenna can also be configured to fit the physical characteristics of where you are. A long whip is a long whip so you have to make it fit. (Example: Inverted L consisted of wire off the radio and run through a 550 cord loop about 3 feet above the radio, wire run out about 15 feet and secured)

I probably could have done a better job of phrasing my question - I don't really envision using the radio much while "moving around". It goes without saying that the long whip is too long for movement, and the doctrinal LRS mission doesn't really call for commo on the move.

Interestingly, though, one of the articles referenced above "AN/PRC-150 HF radio in urban combat" talks about the possibility of infantry units using the 150 as their primary means of commo in MOUT, and even swapping out the long whip with a 3' short whip from a SINGCARS, and just bending the gooseneck horizontal for NVIS commo while fighting. I don't have the experience or background to know how well that would work, but it is an interesting article that helped me think about how I might use the 150 for the LRS mission.

All that said, it is clear that what I need is some quality time with a radio and someone who knows what they are doing with HF in the field. Like most people, I will probably have an "aha" moment when I see someone set up one of these more advanced antennas for the first time. I suspect I will learn a lot at RSLC when I go. I am just trying to educate myself, and have some tools in the toolkit to use when training my soldiers. The 150 is a relatively new piece of gear for my unit (we still have to borrow them from other units to train), and there isn't really anyone I know of in our unit that is a subject matter expert.

Right now, I am in "sponge" mode. Anyone that wants to put in their 2 cents on using manpack 150's in the field, I'd love to hear it.

[albeham]

There is a lot to say when it comes to NIVIS, back-pack comms.

Your going in the right direction, continue to think outside the "BOX'.

I run 5 watts, yep 5 watts with a " End Fed Antenna" 1/2 wave long.

It acts like a dipole, but you feed it at the end, so there is no coax to carry. I do some hiking, and like to have a lighter load then my old commo ruck.

Getting the Far end up above 5 feet, and using low frequencies , 10 MHz below, gets me a NIVIS shot, and if you get it up high 10 feet or more, and with the right high band frequencies, you can talk a hell of a lot further then you think.

When you use a short whip, you are asking the tuner to load the antenna, this could cause your antenna to be ineffective for what you are trying to do, but if it works go with it.

I would use the 16 foot whip, on its side, like what has been said. A vertical gives you ground wave, a horizontal antenna gives you sky-wave. Keep the antenna off the ground, so not to complete the path to ground, that's what you are asking the sky to do for you.

There is a great book out, that was written by a NG O,,"Near Vertical Incidence Sky wave Communications" Its a Ham radio book. But then again we are all Amateurs..

I have a lot more to tell you if you want it, email me, etc.

A radio man is the life line to the team, shooting a gun is nice, but I like to get a ride home, not walk.. :D

ASk away.... AL

PS We did a lot of NIVIS stuff while on the GMV, while on the move..

[bravo22b]

There is a lot to say when it comes to NIVIS, back-pack comms.

Your going in the right direction, continue to think outside the "BOX'.

I run 5 watts, yep 5 watts with a " End Fed Antenna" 1/2 wave long.

It acts like a dipole, but you feed it at the end, so there is no coax to carry. I do some hiking, and like to have a lighter load then my old commo ruck.

Getting the Far end up above 5 feet, and using low frequencies , 10 MHz below, gets me a NIVIS shot, and if you get it up high 10 feet or more, and with the right high band frequencies, you can talk a hell of a lot further then you think.

When you use a short whip, you are asking the tuner to load the antenna, this could cause your antenna to be ineffective for what you are trying to do, but if it works go with it.

I would use the 16 foot whip, on its side, like what has been said. A vertical gives you ground wave, a horizontal antenna gives you sky-wave. Keep the antenna off the ground, so not to complete the path to ground, that's what you are asking the sky to do for you.

There is a great book out, that was written by a NG O,,"Near Vertical Incidence Sky wave Communications" Its a Ham radio book. But then again we are all Amateurs..

I have a lot more to tell you if you want it, email me, etc.

A radio man is the life line to the team, shooting a gun is nice, but I like to get a ride home, not walk.. :D

ASk away.... AL

PS We did a lot of NIVIS stuff while on the GMV, while on the move..

Cool stuff. I am going to try to digest this info and do some more research... I'm not looking to be spoon fed.

At the same time, more info is always good.

A happy coincidence that we've got two SF commo gurus both in MD... which just so happens to be where my unit is (Hagerstown). Maybe at some point I can repay your kindness with some food & drink on me...

[albeham]

I am good with that.

I work at Fort Meade.

Its a Ham thing be glad to help you.


AL

[Ret10Echo]

Cool stuff. I am going to try to digest this info and do some more research... I'm not looking to be spoon fed.

At the same time, more info is always good.

A happy coincidence that we've got two SF commo gurus both in MD... which just so happens to be where my unit is (Hagerstown). Maybe at some point I can repay your kindness with some food & drink on me...


I am good with that.

I work at Fort Meade.

Its a Ham thing be glad to help you.


AL

The fact that we know each other is also somewhat coincidental too.

Thanks for stepping up AL and keeping me straight. :D

[albeham]

Hey its cool, i don't know everything, hell just ask my wife!!!!


AL

[Badger52]

I am good with that.

I work at Fort Meade.

Its a Ham thing be glad to help you.


ALFirst, thanks for your contributions to this thread as well as Ret10Echo's and others. I'll personally vouch that the search engine is still working just fine. Good field-tested info provided herein and better than a new thread.

Being one who would rather have less gear/more Ramen I can vouch for the end-fed wire with some counterpoises, either as a simple/cheap/lightweight setup that has gotten me nearly 1K miles on my 5w, or to solve that other problem:

Can talk x-country but not the friend 95 or 150 miles away. That is where I found there wasn't a substitute for making some research/work investment on the front-end. There are squiggly lines to interpret & a bit of math to do. (Of all the various service field handbooks, the USMC seems to be the best of the bunch.)

Have also learned (with chagrin) that in my climate it's useful to insure in the morning that the counterpoises are still looking up at the world, rather than the night's heavy snowfall.

I am curious to see if bravo22b has some follow-up as to how the various bits of advice worked out for his particular requirement that started the thread.

Thank you again.

[bravo22b]

I am curious to see if bravo22b has some follow-up as to how the various bits of advice worked out for his particular requirement that started the thread.


There is another thread that has some more good info, and also summarizes the results of a COMMEX we had with the 150.

http://www.professionalsoldiers.com/forums/showthread.php?t=30107

Since this thread, I have had a chance to do more work with the 150 on shorter range stuff as well.

My unit has a COMMEX this coming weekend with the Georgia LRS unit. I will be busy with other things but I will get some feedback on how it goes and what freqs and antennas they use.

I still owe Albeham and Ret10Echo some food and beer. Gentlemen, I am doing the Army's work full time now, you let me know when is a good time.

[Badger52]

There is another thread that has some more good info, and also summarizes the results of a COMMEX we had with the 150.

My unit has a COMMEX this coming weekend with the Georgia LRS unit. I will be busy with other things but I will get some feedback on how it goes and what freqs and antennas they use.Trackin', thanks.

[albeham]

Any update to this? Would like to hear how it turned out for you all.


AL


PS JOTA :munchin

[2018commo]

My favorite for NVIS was a slant wire with a teaser to adjust TO angle and a terminating resister at the end of the counterpoise. Worked well in the winter out west and the Flintlock/ Reforger trips in Europe. Did one on a 77 in Pathfinder School and talked to Lawson Airfield from the LZ at Darby. The guys with the Bert and Earnie haircuts were scratching their heads and yes it was a good day to be SF!

[bravo22b]

So this summer my unit spent three weeks in Australia for Talisman Sabre 2011. Our teams conducted missions that ranged from 30-70 km away from our COB. Primary means of communication was HF with the 150, with some teams having TACSAT for alternate means using MBITR's.

We had to beg, borrow, and steal the equipment we needed to make this work, but we were able to come up with a limited number of Toughbooks, and we had enough MBITR's for two per team, and a handful of TACSAT antennas. One of our best assets is actually one of our E-5 riggers, who works for the State Department as a commo guru, and took charge of our commo section for this exercise.

One of the biggest limitations we had was batteries. We were unable to get 5590 adapters for the Toughbooks, so as anyone who has ever used one knows, battery life is very limited. Also, the 5590s that we took for the 150 were old and did not have their full life expectancy. For MBITR's, we had a limited number of rechargeable batteries and again no 5590 adapters.

My team spent 5 days out without resupply and battery life was definitely a major concern. The Toughbook lasted about 1.5 days using Tac Chat, and then we had to go to digital voice. The MBITR's lasted the whole time, but only because we only used them during commo windows and I used the 150 to monitor FM for intra-team communications most of the time. I also kept one MBITR battery in reserve so that we would have TACSAT for emergency use.

On the HF side, we used mostly the Harris RF-1940 antenna, with a field expedient antenna for a backup if necessary. Operation was in 3G mode. One issue we kept running into was the radio losing its TOD sync. I am not sure what was causing it to lose sync so quickly, but in about a 12 hour period we were losing it. This caused a problem during our first commo window because we had lost sync completely, so could not do an LQA to try to get our antenna configuration worked out. We had to resort to using TACSAT for our first commo window and doing a manual TOD reset.

Once that issue was resolved we had fairly good success during the rest of our mission using HF. We experimented with different antenna configurations and concluded that a dipole approximately 5' off the ground using the Harris antenna was the best configuration. We experimented by reproducing that configuration using our field expedient claymore wire dipole, and interestingly enough, it actually had a better LQA score on our best channel at that time, but dramatically worse on the other channels. Given the transmitting distance I am fairly confident that we were using NVIS and not a ground wave.

It was excellent training for us. My RTO and ARTO got a lot of practice setting up the antennas and using the radios, became fairly proficient at using the Toughbook and TAC Chat, and came to understand a little bit of the complexity of using HF. They recorded LQA's at each commo window and got to see how the link quality went up and down for different channels based on the time of day, so now they have a better understanding of that aspect of HF.

All in all, we feel like we accomplished a lot during that exercise. All teams made HF comms during their missions, and most if not all teams had some success with TAC Chat and sending some digital imagery of their NAI back. Considering that we are talking about NG 11B's who do not do this every day and have limited experience with this equipment, I think that qualifies as success.

Our key take aways, some of which may be obvious to an 18E, but nonetheless:

5590 adapters are a must for long missions
PCC/PCI's - radio checks not just the morning of the mission, but immediately before moving out
The importance of PACE (or at least PA)
Trying to transmit lots of information on digital voice sucks
The importance of adjusting your HF antenna to get the best results

Hope some of this helps somebody else.

[Ret10Echo]

Our key take aways, some of which may be obvious to an 18E, but nonetheless:

5590 adapters are a must for long missions
PCC/PCI's - radio checks not just the morning of the mission, but immediately before moving out
The importance of PACE (or at least PA)
Trying to transmit lots of information on digital voice sucks
The importance of adjusting your HF antenna to get the best results



Thanks for the post bravo...Can't help but notice that some things never change.... :D

[Traweek]

Thanks for the post bravo...Can't help but notice that some things never change.... :D

With that little AAR it looks like he will be ahead of the game next time.... and some things never change.... except weight, things seem to be getting heavier now-a-days

[Ret10Echo]

With that little AAR it looks like he will be ahead of the game next time.... and some things never change.... except weight, things seem to be getting heavier now-a-days

Don't get going about weight....(her come the FOG's) :D

Considering the days of the PRC-70, G-76s, BB-542s and DMDGs...and P-A-C-E meaning different pieces of hardware (as opposed to different modes of comm that may reside in the same metal case)

Heavy is relative...:rolleyes:

[Badger52]

Once that issue was resolved we had fairly good success during the rest of our mission using HF. We experimented with different antenna configurations and concluded that a dipole approximately 5' off the ground using the Harris antenna was the best configuration. We experimented by reproducing that configuration using our field expedient claymore wire dipole, and interestingly enough, it actually had a better LQA score on our best channel at that time, but dramatically worse on the other channels. Given the transmitting distance I am fairly confident that we were using NVIS and not a ground wave.

It was excellent training for us. My RTO and ARTO got a lot of practice setting up the antennas and using the radios, became fairly proficient at using the Toughbook and TAC Chat, and came to understand a little bit of the complexity of using HF. They recorded LQA's at each commo window and got to see how the link quality went up and down for different channels based on the time of day, so now they have a better understanding of that aspect of HF.
Good stuff, thanks for the follow-up. Sounds like you also had the opportunity to play with different heights above ground and that can be very illuminating.
:)

[bravo22b]

So it is that time of year for us again, our LRS teams are going out for an urban surveillance FTX. Primary comms will be HF with the 150 as in the past. Distance of the HF shot will be appx. 115 km.

Over the past couple years we have built up a good basic level of skill using dipoles, but given the goal of setting up an antenna in an urban environment and staying concealed, that does not seem like the best choice. I'm not saying that you cannot set up a dipole and keep it concealed in a real city given the time and materials, but it is probably not practical given the time and material constraints we are operating under. In addition, the training venue is a MOUT site, and there is not a lot of existing wires, clotheslines, or the like that you could conceal an antenna alongside.

I have done some research, in particular an article in the spring 2004 edition of Army Communicator called "AN/PRC-150HF Radio in Urban Combat" which has a lot of good info.

I have used a field expedient square loop antenna once in the past successfully, and I plan on trying that again. I would be interested to hear any other suggestions on good techniques for urban HF. Our constraints are basically that we can't afford to buy new gear, so we will be using either the 10' whip, Harris RF-1940 antenna, or field expedients.

[glebo]

Do you have an amp with that?? If not, you're doing NVIS, which I'm sure you know. Try using a vertical on the upper part of the HF spectum. Vertically polarized signals will not attenuate as quickly as horizontal (however, they are omni-directional as far as RDF threats are concerned)...Are ya gonna be able to do any test shots to try and experiment??

If ya have room/concealment, also try the AS-2259 NVIS antenna that came out with the 104. Basicaly, two inverted V's fed from the same feed point. As long as the 150 can match it. (SWR wise)

Good luck..

[bravo22b]

Do you have an amp with that?? If not, you're doing NVIS, which I'm sure you know. Try using a vertical on the upper part of the HF spectum. Vertically polarized signals will not attenuate as quickly as horizontal (however, they are omni-directional as far as RDF threats are concerned)...Are ya gonna be able to do any test shots to try and experiment??

If ya have room/concealment, also try the AS-2259 NVIS antenna that came out with the 104. Basicaly, two inverted V's fed from the same feed point. As long as the 150 can match it. (SWR wise)

Good luck..

We don't have any amps. As you say, I expect to be doing NVIS so I am trying to expand my knowledge base of improvised antennas that will fit inside of a building but also get me some good upward radiation.

I think we are going to have a BRS set up within about 20 kilometers as a backup to our longer shot. That way if the teams are unable to get comms using NVIS they can at least have an alternate station to pass up their reports to.

My tentative plan is to start off with a couple different NVIS antennas and then if I can't get anything with those try a 1/4 or 1/2 wavelength vertical on the closer BRS. Being as we will be hiding out in a building for about 24 hrs. it should give us plenty of time to play with different configurations.

[Badger52]

If ya have room/concealment, also try the AS-2259 NVIS antenna that came out with the 104. Basicaly, two inverted V's fed from the same feed point. As long as the 150 can match it. (SWR wise)

Good luck..Glad you mentioned that; good catch. This is a rather neat antenna and has some EMCOMM uses which I've been exploring however, as dimensioned, it either needs loading coils or has to be recut a good bit longer for civ use (or use a heckuva good tuner). Not sure how much VSWR the 150 handles w/o its coupler but I recall seeing some pretty high numbers outside the 5.9 or 9.1 MHz areas as presented at the feedpoint.

bravo22b, I'll assume hiding means just that & roof-top footprint isn't an option, or is that available as something for the AS-2259, which I think is now Harris' RF-1936?

Good luck; watching with interest (again).

[bravo22b]

Glad you mentioned that; good catch. This is a rather neat antenna and has some EMCOMM uses which I've been exploring however, as dimensioned, it either needs loading coils or has to be recut a good bit longer for civ use (or use a heckuva good tuner). Not sure how much VSWR the 150 handles w/o its coupler but I recall seeing some pretty high numbers outside the 5.9 or 9.1 MHz areas as presented at the feedpoint.

bravo22b, I'll assume hiding means just that & roof-top footprint isn't an option, or is that available as something for the AS-2259, which I think is now Harris' RF-1936?

Good luck; watching with interest (again).

Each of our teams will be in a different building ranging from a 3 story "hotel" with a nice big flat roof with a parapet to smaller 1 and 2 story buildings with pitched roofs. Given that our mission calls for being undetected, each team has to come up with a plan for their antenna that accommodates the size and type of building they are in. A team in a building with a flat roof and a parapet may be able to get away with installing an antenna up on the roof, a team in a small building with a pitched roof probably needs to plan to keep it inside the building. Given the physical size of a 1/4 wavelength antenna in the 2-8 MHz range, not too many teams are going to be able to plan to erect a dipole, or an inverted V.

Part of the goal of our training is to increase the complexity as the teams become more proficient. This exercise should make them think a little bit and hopefully learn more about how to do HF.

[glebo]

b22,

given the low freq you're operating on, which will dictate resonant antenna length (which will be long), you can also alter the physical characteristics of the antenna. Just make sure each leg is as symetrical as you can get it. I've seen "V"'s/doublets legs zig-zagged to fit in a confined space and they worked. You may also try "coiling" each leg around a 6" dia. or so piece of PVC pipe to. Make sure you have even spacing on the wire, hold in place with tape. Obvioulsy, the less altering, the less you'll be taking away from antenna characteristics and efficiency.

At that range, you'll be somewhat omni-directional anyway.

You should still be able to get out some good useable signal from the antenna..

As always, it all depends on how well the freq's you're using are propping though. You can have all the power in the world, best antenna, but if the freq's not there...you're wasting your time.

[Badger52]

given the low freq you're operating on, which will dictate resonant antenna length (which will be long), you can also alter the physical characteristics of the antenna.Fellow I know is residential "lot-size constrained" and has a double-bazooka, resonant at 3.9 and has it running around in a very lazy, but very symmetrical "W". He does his inside 300-mi thing with no problem (other than the aforementioned radio gods having a bad day). Not specifically to b22's situation but you've shown benefits of getting one's head out of the dicta.

b22's variety of site challenges makes this interesting.

[glebo]

Fellow I know is residential "lot-size constrained" and has a double-bazooka, resonant at 3.9 and has it running around in a very lazy, but very symmetrical "W". He does his inside 300-mi thing with no problem (other than the aforementioned radio gods having a bad day). Not specifically to b22's situation but you've shown benefits of getting one's head out of the dicta.

b22's variety of site challenges makes this interesting.


awsome, good deal. "Bazooka"...I remember that term..cool.:D

You'd be surprised at what ya can do with an antenna...as long as you don't get to crazy..

[bravo22b]

b22,

given the low freq you're operating on, which will dictate resonant antenna length (which will be long), you can also alter the physical characteristics of the antenna. Just make sure each leg is as symetrical as you can get it. I've seen "V"'s/doublets legs zig-zagged to fit in a confined space and they worked. You may also try "coiling" each leg around a 6" dia. or so piece of PVC pipe to. Make sure you have even spacing on the wire, hold in place with tape. Obvioulsy, the less altering, the less you'll be taking away from antenna characteristics and efficiency.

At that range, you'll be somewhat omni-directional anyway.

You should still be able to get out some good useable signal from the antenna..

As always, it all depends on how well the freq's you're using are propping though. You can have all the power in the world, best antenna, but if the freq's not there...you're wasting your time.

Thanks for the advice, I find it very educational. Since my guys will have some time to kill during the surveillance portion of the mission (rest plan, what rest plan?) I may try to set up something like you describe.

As far as freqs, we have our VOACAP prediction which shows we should be able to have good comms between 3-6 MHz, but whether the spectrum management people give us the right freqs is, unfortunately, out of our hands.

[Badger52]

awsome, good deal. "Bazooka"...I remember that term..cool.:D

You'd be surprised at what ya can do with an antenna...as long as you don't get to crazy..A double-bazooka made right, vice the other 999 versions somewhere on the internet that don't take velocity-factor into account (with subsequent complaints that they don't work). Then again, it might be too heavy to haul in unless you get some super low-loss high-$ low-payload coax like DoD uses all the time. Oh. Wait...

..but whether the spectrum management people give us the right freqs is, unfortunately, out of our hands.IIRC that's on the standard list somewhere of a signaleer's alibis. 'Course 5x5 is better than an alibi anytime.

I like glebo's idea of wire around a PVC, assume here basically talking about using loading coils to make the wire electrically longer than it really is, ergo more portable & "hide-friendly" no?

[MD2colo]

I really like these 150s...
Been using a pair of them to send data to a distance of about 300 mi here in A-stan. Not sure when/if 19th group with ever get them, since 137s fill the HF role but they are cool for a non-SOF ALE radio.

THe third generation ALE works great... better than I expected.
Base station has a 2259 NVIS antenna and the outstations have the radios in the vehicles, coax out to a cobra head with 18' of speaker wire off of the hot side and the negative post grounded to the truck frame. wire is ran up an FM antenna and tied to the back of the truck. not the sexiest thing you ever saw, but it works. Hell of a lot more lo-pro, also.

Used the VOACAP online prediction website to get in the ballpark, freq manager did his best to hook me up but I was impressed with how easy the VOACAP is to use... for me the other programs like DXprop and the like are too difficult to understand. probably my fault tho.

[bravo22b]

It's been a while since I have posted anything on this, but I thought I would add something as my unit increases its' proficiency and experience with using the 150. Our drill this past weekend took us to Camp Santiago, Puerto Rico and one of our training goals was to do HF shots back to Hagerstown, MD. Total distance was approximately 2640 kilometers.

We had extremely limited training time and real estate, so we weren't able to get each LRS team set up with their own antenna, but our commo section got a sloping vee set up using a Harris RF-1940 antenna, and got very good link quality back to Hagerstown. I don't have the LQA scores handy, but it was good enough link quality over 3G ALE to use digital voice without a lot of problems.

The antenna was set up on a hilltop with the apex about 18' off the ground on a OE-254 mast, legs approximately 75' long (whatever the standard length of the RF-1940 leg is), and spread about 50'-60' apart.

I'll see if I can get any more details and post them if I do.

[69harley]

It's been a while since I have posted anything on this, but I thought I would add something as my unit increases its' proficiency and experience with using the 150. Our drill this past weekend took us to Camp Santiago, Puerto Rico and one of our training goals was to do HF shots back to Hagerstown, MD. Total distance was approximately 2640 kilometers.

We had extremely limited training time and real estate, so we weren't able to get each LRS team set up with their own antenna, but our commo section got a sloping vee set up using a Harris RF-1940 antenna, and got very good link quality back to Hagerstown. I don't have the LQA scores handy, but it was good enough link quality over 3G ALE to use digital voice without a lot of problems.

The antenna was set up on a hilltop with the apex about 18' off the ground on a OE-254 mast, legs approximately 75' long (whatever the standard length of the RF-1940 leg is), and spread about 50'-60' apart.

I'll see if I can get any more details and post them if I do.

Good job. What can you tell us about the setup at the base station Hagerstown?

[bravo22b]

Good job. What can you tell us about the setup at the base station Hagerstown?

Our BRS in Hagerstown also had a sloping vee antenna, set up on the roof of our building. Initially when they were trying to make comms at night, PR could hear Hagerstown but Hagerstown could not hear PR. In the morning, the antenna in PR was adjusted and they were able to get good traffic both ways with voice and Tac Chat. I think the highest LQA was a 35.

One of the theories being discussed is that there is a large solar panel array (several acres) and power lines just south of our building in Hagerstown, on the transmission path, and that there may have been some EM interference that was affecting the weaker incoming signal more than the stronger outgoing signal. It's hard to know, but it sounds plausible.

Both stations were using un-amplified PRC-150's on high power (20 watts) and the Harris RF-1940 antennas.

[69harley]

Those solar panels may have been a source of interference, but being in the transmission path is of little consequence. The electrical noise, whether it is in the path or not, may sort of drown out the weaker signal of the distant station, but does not absorbe or 'block' the transmission.

Sort of like while peeing in the bathroom, I cant understand what my wife is saying in the next room. But she can hear me just fine.

Did reliable two-way comms ever happen at night between PR and Hagerstown?

PR to Hagerstown on two 20 watt radios and what are basically a manpack dipole antennas is pretty good.

How HF is typically worked is the base station will have larger, higher gain antennas and amplifiers, and the out stations have smaller, lower powered radios and antennas with less gain. The base station antennas are typically very large, this allows them to reliably receive the weak transmissions from the outstaions. The amplifiers allow the base stations to blast out to the smaller antennas used by the out stations. Having the same setup, manpacks and small dipoles (sloping v), is challenging and on the fringes of workable link margins.

Even though the antenna in PR was adjusted in the morning and then comms were established, I suspect the real cause was the sun came up and polarized the ionosphere. IME. that shot is much easier to close the loop on during the day than at night.

Good job. Glad to see units learning and using HF.

[Badger52]

Even though the antenna in PR was adjusted in the morning and then comms were established, I suspect the real cause was the sun came up and polarized the ionosphere. IME. that shot is much easier to close the loop on during the day than at night.

Good job. Glad to see units learning and using HF.Cool stuff indeed and I agree. Certain bands can be very sensitive that way, and just a few more degrees of sun above the horizon - literally wait a few minutes - can make a huge diffference.

[glebo]

Are you guys propin' for mid path, or area of refraction ??

[bravo22b]

Those solar panels may have been a source of interference, but being in the transmission path is of little consequence. The electrical noise, whether it is in the path or not, may sort of drown out the weaker signal of the distant station, but does not absorbe or 'block' the transmission.

Sort of like while peeing in the bathroom, I cant understand what my wife is saying in the next room. But she can hear me just fine.

Did reliable two-way comms ever happen at night between PR and Hagerstown?

PR to Hagerstown on two 20 watt radios and what are basically a manpack dipole antennas is pretty good.

How HF is typically worked is the base station will have larger, higher gain antennas and amplifiers, and the out stations have smaller, lower powered radios and antennas with less gain. The base station antennas are typically very large, this allows them to reliably receive the weak transmissions from the outstaions. The amplifiers allow the base stations to blast out to the smaller antennas used by the out stations. Having the same setup, manpacks and small dipoles (sloping v), is challenging and on the fringes of workable link margins.

Even though the antenna in PR was adjusted in the morning and then comms were established, I suspect the real cause was the sun came up and polarized the ionosphere. IME. that shot is much easier to close the loop on during the day than at night.

Good job. Glad to see units learning and using HF.

I don't think they ever did get two-way comms at night, so reading your comments it makes sense that it has more to do with time of day than adjustments to the antenna.

I don't think the guys have ever put a lot of thought into a permanent antenna array here in Hagerstown, although maybe we should. As you know, our mission usually has us setting up BRS's in temporary locations, usually co-located with our TOC. But it might be worth setting up a bigger and better antenna here if for no other reason than good training.

Posted by Glebo - Are you guys propin' for mid path, or area of refraction ??

I'm sorry, come again? I doubt I really understand what you're asking, but with regards to propagation models I believe that at the company and BN level we have some propagation software (not sure the name, but I can find out), but I'm not sure what if anything they are using at the State G-6 where they are assigning our frequencies. My suspicion is they are using a Magic 8-ball or maybe a 12 sided dice.

For my purposes as a LRS TL, I usually run a VOACAP prediction just to get a ballpark sense of what I am looking at. Unfortunately VOACAP doesn't seem to have antenna parameters that really fit what we are using, so I think the accuracy is probably lacking.

[glebo]

copy

"I'm sorry, come again? I doubt I really understand what you're asking, but with regards to propagation models I believe that at the company and BN level we have some propagation software (not sure the name, but I can find out), but I'm not sure what if anything they are using at the State G-6 where they are assigning our frequencies. My suspicion is they are using a Magic 8-ball or maybe a 12 sided dice.

For my purposes as a LRS TL, I usually run a VOACAP prediction just to get a ballpark sense of what I am looking at. Unfortunately VOACAP doesn't seem to have antenna parameters that really fit what we are using, so I think the accuracy is probably lacking."


I'm sure the prop programs do that (mid path), I haven't used them in ages....

As far as antenna info. If you have the usual radiation patterns of the normal antennas (doublets, Sloping V's, Longwires) on a graph (depicting the radiation angles of that antenna at various electrical hieghts above ground), all ya need to figure out is the take off angle from you to the distant station. Once you determine that, raise/lower your antenna according to the major lobe of radiation plotted on the antenna chart to that angle...(to go from point A to point B), no matter what antenna you're using. It's all about the take-off angle and your orientation of the major lobe of radiation(strongest) on that angle.

I'll try and find some of our handout stuff we used and try and post them...

Oh...keep a GOOOD log book so you don't have to go through this asspain again if you find yourself doing it in the same area later...

Hope this wasn't to confusing...kinda got on a roll...

[Badger52]

...but I'm not sure what if anything they are using at the [fill-in higher HQs] where they are assigning our frequencies. My suspicion is they are using a Magic 8-ball or maybe a 12 sided dice.Feel your pain; that probably sounds familiar to many here.

glebo's advice re logging can = workarounds to the voodoo above.

[69harley]

VOACAP will provide the take off angle, right down the the minute of the day.

Run VOACAP, determine when you plan to make comms, then look at the radiation angle chart. Then determine the FOT for each planned window and the take off angle for the time of the window and plug them into the antenna modeling portion of VOACAP. You will have to play around with the lengths, heights, etc, in the software, but it will get real close. Build your antenna as close to the specs that the software modeled.

[69harley]

Ignore everything a freq manager tells you about HF.

Run your prop, make your best guestimation, listen to your chosen frews for a day or two before using them (just to make sure they are not being used and to check for noise/interference).

[69harley]

As you know, our mission usually has us setting up BRS's in temporary locations, usually co-located with our TOC. But it might be worth setting up a bigger and better antenna here if for no other reason than good training.

I was a LRS Commo Sergeant for 12 years, 82nd, Korea, 18th ABN Corps.

Regardless of location, the BRS should always have a larger antenna and higher power than what the teams have. The teams are limited by the tactical situation and weight. The BRS has no real contraints. The BRS team should always use their amplifiers and couplers as well as set up multiple base station type antennas. Always.

[bravo22b]

I was a LRS Commo Sergeant for 12 years, 82nd, Korea, 18th ABN Corps.

Regardless of location, the BRS should always have a larger antenna and higher power than what the teams have. The teams are limited by the tactical situation and weight. The BRS has no real contraints. The BRS team should always use their amplifiers and couplers as well as set up multiple base station type antennas. Always.

Roger, I probably phrased my reply poorly. Our BRS's typically do set up multiple antennas, and they do use amplifiers when possible (we have a severe shortage of amplifiers vs. our MTOE). What I intended to convey was that we hadn't really considered setting up a permanent antenna array at our armory in Hagerstown because that is not typically where we operate from, but that we probably should. That said, our BRS that was set up in PR was constrained both by time but also by equipment. Space on the C-130's was limited and they basically had with them what they could hand carry in their rucksacks plus one OE-254. Your point is well taken , though.

As far as the other comments from you and Glebo regarding takeoff angle and propagation, I think we have a decent working understanding of that, at least enough to get the basics. One of the things we focused on training our LRS teams this weekend was the fundamentals of using the propagation model to predict takeoff angle and which antenna to use based on that. I carry around a miniature copy of the USMC antenna manual which is a great reference for me to show soldiers the takeoff angle charts. We do also teach them to use log books, although I suspect most go through the motions at best. Still, it's a start.

What success we did have was on frequencies that, shall we say, accidentally found their way into the RPA program rather than the ones issued to us by the frequency manager.

[glebo]

69 Harley's on it. That'll do it..yeah, I forgot about the T/O angles on the props...been awhile..

Experience/guestimation is the key...after all it's HF...to some, it's verrry scaaaryyy....LOL..:eek:

But it works, and is reliable when ya get it down. Just gotta convince these "O" types ya don't need a friggin powerpoint for msg traffic...:(

[albeham]

"What success we did have was on frequencies that, shall we say, accidentally found their way into the RPA program rather than the ones issued to us by the frequency manager. "

Careful.... There is a lot of others out there that still us the hell out of HF.


There is a reason why we have and use Frequency Managers...


AL

[glebo]

"What success we did have was on frequencies that, shall we say, accidentally found their way into the RPA program rather than the ones issued to us by the frequency manager. "

Careful.... There is a lot of others out there that still us the hell out of HF.


There is a reason why we have and use Frequency Managers...


AL

that is true, unfortunatley some times the useable freqs aren't approved as we all know.

Ahh, the 'ol "bootleg freq's"...LOL

[69harley]

"What success we did have was on frequencies that, shall we say, accidentally found their way into the RPA program rather than the ones issued to us by the frequency manager. "

Careful.... There is a lot of others out there that still us the hell out of HF.


There is a reason why we have and use Frequency Managers...


AL

Freq managers have not caught up with current HF technology, especially in regards to the PRC-150 with 3rd Generation ALA and LPI/LPD. In regular 3G mode the radio will listen to a freq before transmitting on it, in LPI/LPD mode the radio will jump around, not transmitting on the same freq twice. Typical been counting freq managers plan for exclusive use of freqs as if they will be in constant use. That technique may have been neccassary twenty years ago, but not now.

[albeham]

OK cool..

But don't you still program the freqs in to the radio, so each radio knows what channel to use?

If so, you need to request the use of theses freqs. even for a ALE type radio like the 150. Unless regs have changed since I use them this morning. Freq Managers are up to date, might be the person you go to that is not doing his/her job..you do go to your S-6 and get freqs..right?

even with LPI/LPD emissions, there is still a need to get them assignment, it helps to protects you from EMI to others and others to you. ( in a nice world) Boat legging freqs is not good.

That statement you gave tells me that you don't have or use your Freq manager.

twenty years ago..I ant that old....

I have not had time with the 150 so a good lesson is in store for me. :munchin

[BMT (RIP)]

7th Gp didn't have 150's when this happened.
I took a young radio op toget his one time pads.
After signing for the pads he said" BTW Chief what's that number you divide into the freq toget the antenna length".

BMT

[albeham]

I remember well.

The days of old... and every radio op knew better then the S-6.. LOL


AL

69harley:

As I talked to another GRP Spectrum Manager, that working in the field I do now. we do recall another radio we used. LPI/LPD I do reminder using a radio type that got spectrum support from its the Base station. See what happens when you become a big brain engineer.. We used it for a good portion of my 17 years in 5th grp. But an ALE type system still needs assignments for it operates on discreet channels. See in where one would not need to go to the S-6 for freqs, but they are still managed in the base-station by a controller.

Am I now understanding your statement?

[Badger52]

I remember well.

The days of old... and every radio op knew better then the S-6.. LOL


ALThink they didn't count that high in my day; someone got parked in the Bn 3 shop on their way to goin' somewhere else, bestowed a title called C&E officer and quite often the operators did know more. Times like that make for entertaining threads about "why can't we make comms?"
:D

[mark46th]

I used crystals to set frequencies on the ANG/RC109. It looks like things have changed over the years.

[albeham]

I used crystals to set frequencies on the ANG/RC109. It looks like things have changed over the years.


A little, but its still magical ...

:D

[BMT (RIP)]

7th Gp had a C&E officer even in 1971.

BMT

[69harley]

OK cool..

But don't you still program the freqs in to the radio, so each radio knows what channel to use?

If so, you need to request the use of theses freqs. even for a ALE type radio like the 150. Unless regs have changed since I use them this morning. Freq Managers are up to date, might be the person you go to that is not doing his/her job..you do go to your S-6 and get freqs..right?

even with LPI/LPD emissions, there is still a need to get them assignment, it helps to protects you from EMI to others and others to you. ( in a nice world) Boat legging freqs is not good.

That statement you gave tells me that you don't have or use your Freq manager.

twenty years ago..I ant that old....

I have not had time with the 150 so a good lesson is in store for me. :munchin

Military Automatic Link Establishment (ALE) and LPI/LPD work sort of different from each other. With the legacy HF radios, ie 74,70, 104, the base station would monitor a bunch of freqs and outstations would select the best one for them.

ALE sort of automates the process and allows a single radio in the base station to monitor a bunch of freqs. The radios ping each other, score the channel quality and then link on the best channel. LPI/LPD adds a slight variation in that once the radios link on a chennel, they then begin to hop around, going higher and lower than the center freq.

So yes, freqs are still programed into the radio, but they are not always 'fixed'.

[glebo]

Military Automatic Link Establishment (ALE) and LPI/LPD work sort of different from each other. With the legacy HF radios, ie 74,70, 104, the base station would monitor a bunch of freqs and outstations would select the best one for them.

ALE sort of automates the process and allows a single radio in the base station to monitor a bunch of freqs. The radios ping each other, score the channel quality and then link on the best channel. LPI/LPD adds a slight variation in that once the radios link on a chennel, they then begin to hop around, going higher and lower than the center freq.

So yes, freqs are still programed into the radio, but they are not always 'fixed'.

Correct, the two different ALE's are SOF ALE (which is also LPI/LPD) which scans the spectrum and links up automatically without preprogrammed freqs and MIL STD ALE, which you program a set of hopefully useable freq's and it scans those freq's to link up.

[albeham]

Correct, the two different ALE's are SOF ALE (which is also LPI/LPD) which scans the spectrum and links up automatically without preprogrammed freqs and MIL STD ALE, which you program a set of hopefully useable freq's and it scans those freq's to link up.


Yes I know.... D. all of the above.

Glad to see there are smart folks out there still..

AL :D

[glebo]

Yes I know.... D. all of the above.

Glad to see there are smart folks out there still..

AL :D

I know, I was just throwing it out there in case there was any confusion....between the two different systems and their technique of ALE...

gotta love HF "magic"..:D

[albeham]

I am with you.

I spoke before I read..shame on me.

What I do now is not the cool shit we use to do, but I get into a lot of IFF, SAT, 1494s, SPEC21, etc. and there spectrum support.

Miss the days of really playing HF. I was told once that I was too military minded when it came to everything.. I said with "SO", but I did open my mind set to the many other paths of RF, that one can get into out here as a commo god. But at times even a commo god needs to remember his past.

There is still a lot of spectrum that needs attending... :D

AL

[Joshua.David]

We "briefly" covered the 15o in the echo course. The power point was brand new and we basically roughed our way through it. Honestly disregarded the entire platform and was told to use the 137 it is a better system. Although I heard they have gone a bit more in-depth with it now and it is actually a testable system and it being used.

I'd like to find more out about it and people thoughts and reviews.
-josh

[Aimpoint]

Hey all. Hopefully this thread hasn't died. I'm an 11B on one of the teams in Hagerstown, currently the RTO. I've been RTO for the past 4 years, and I really wouldn't trade it for anything else- it's a good feeling when we're in a hurricane and all the teams can't make comms except for yours ;). Anyways, AT is coming up so I'm trying to get up on all my radio knowledge (again). Its tough because this stuff really is a perishable skill.

A couple of drills ago, our teams were being graded on our basic skills by the det LT- insertion, SILS, hand and arm signals, ANGUS, ect... To make a long story short, myself and the ARTO were running our RF-1940 antenna up, and the LT (who was fairly new to LRS) and the TL (also fairly new) were dumfounded as to why it took SO FRIGGIN LONG. Now there's always room for improvement, but the ARTO and myself can do it pretty quick. At least as quick as the 1940 could ever go up. It really made me realize how vulnerable the team is when doing a commo shot, and how much attention it draws.

I'd like to avoid the 1940 at all costs this AT. Avoiding the whip would be nice too, as it makes metal on metal noise that can be identified at a distance. Is there a field expedient method that would give similar capabilities? I've thought about rolling up some commo wire (or similar) into my ruck, and just unfurling it while doing comms. Would this would have to be cut for freq , or can the 150 tune to pretty much any length of wire? Currently have the 7-93 and FM 6-02 in hand, but no experience with field expedient methods.

[69harley]

The 1940 as I recall is a dipole antenna kit manufactured or sold by Harris.

Hmmm, were to start. The antenna type is really driven by the distance between the two radios and transmitter power. Low hanging dipoles work pretty good for short range NVIS shots and verticle whips with their lower take off angles are good for longer range shots (ie Ft. Bragg to Ft. Polk).

The take off angle of a dipole is tuned by raising and lowering the feed point. Good rule of thumb is higher feed point, equals a lower take off angle, and vise versa, lower feed point will give a higher take off angle.

If you are not already doing this, ask the commo section for the antenna analysis and propogation charts for the exercise. You really want these in electronic format so that you can click around on the screen and determine various take off angles and other key bits of information, like signal to noise ratio. Look at your window times on the prop chart. It may be that signal to noise ratio will change drastically within your window. It may be planned up front that you will attempt comms in the last half of the window, etc.

Many a team has found success with some variant of the 112' (or so) long piece of wire. Start with simple and easy and work your way up to large and complex. The best antenna is the smallest and easiest one that closes the circuit with an acceptable link margin.

The ALE aspect of the 150 makes cutting resonant antennas somewhat of a compromise. I would look at the freqs in the RPA and cut a few antennas to those freqs.

If you don't already have a sling shot in your antenna kit you should get one. I think more noise and movement is made trying to get a rope over a tree branch than any other commo activity. Use some small green rope and a medium sized fishing weight, or the rope from a GRA-50. Use the sling shot to shoot the weight over the branch. Practice this a few times before going to the woods with your team. Bring a couple ropes in case one gets caught.

[Aimpoint]

The 1940 as I recall is a dipole antenna kit manufactured or sold by Harris. Roger, it's a dipole kit although we usually run it in a sloping v.


Look at your window times on the prop chart. It may be that signal to noise ratio will change drastically within your window. It may be planned up front that you will attempt comms in the last half of the window, etc.
Awesome tip. It didn't occur to me that the s/n ratio would change during the window.

If you don't already have a sling shot in your antenna kit you should get one. I think more noise and movement is made trying to get a rope over a tree branch than any other commo activity.
That's a GREAT idea. Getting the rope up is damn noisy, especially in the dark. Sending an ANGUS with the 1940 kit at 0200 when there's a time hack (eyes on) is counterproductive, IMO. In addition, security hasn't really been established, and it's noisy as hell... just a bad idea. One day we'll get dedicated SATCOM :rolleyes:


I forgot we're doing a CALFEX, which is graded, so experimentation at the hide probably won't happen. Hoping to run the whip, which is fine. Thanks for the tips.

[69harley]

Sending an ANGUS with the 1940 kit at 0200 when there's a time hack (eyes on) is counterproductive, IMO. In addition, security hasn't really been established, and it's noisy as hell... just a bad idea. One day we'll get dedicated SATCOM :rolleyes:

I was a LRSD & LRSC Commo chief for over twelve years and this does not sound right. Typically, a LRS team inserts at first dark and does not have a planned window until first light. We used to have teams come up on SATCOM voice to send an ANGUS one terrain feature away from insertion, but over time that was deemed not neccasarry. The guys on the insertion aircraft confirm the team was inserted. Having the team do anything between insertion and sunrise just takes away precious time for movement and digging.

[bravo22b]

Hey all. Hopefully this thread hasn't died. I'm an 11B on one of the teams in Hagerstown, currently the RTO. I've been RTO for the past 4 years, and I really wouldn't trade it for anything else- it's a good feeling when we're in a hurricane and all the teams can't make comms except for yours ;). Anyways, AT is coming up so I'm trying to get up on all my radio knowledge (again). Its tough because this stuff really is a perishable skill.

A couple of drills ago, our teams were being graded on our basic skills by the det LT- insertion, SILS, hand and arm signals, ANGUS, ect... To make a long story short, myself and the ARTO were running our RF-1940 antenna up, and the LT (who was fairly new to LRS) and the TL (also fairly new) were dumfounded as to why it took SO FRIGGIN LONG. Now there's always room for improvement, but the ARTO and myself can do it pretty quick. At least as quick as the 1940 could ever go up. It really made me realize how vulnerable the team is when doing a commo shot, and how much attention it draws.

I'd like to avoid the 1940 at all costs this AT. Avoiding the whip would be nice too, as it makes metal on metal noise that can be identified at a distance. Is there a field expedient method that would give similar capabilities? I've thought about rolling up some commo wire (or similar) into my ruck, and just unfurling it while doing comms. Would this would have to be cut for freq , or can the 150 tune to pretty much any length of wire? Currently have the 7-93 and FM 6-02 in hand, but no experience with field expedient methods.

Aimpoint -

I applaud you on your motivation and initiative. As you can see, I use this board as a resource to find answers to questions just like you do. As usual, you got some great advice here. That said, the answers to your questions can also be answered within the unit by just asking the right people. The RF-1944 antennas are difficult to set up quickly, although with a lot of practice and some modifications, they can be set up pretty quickly, even at night. I would be happy to show you how to do it faster and more efficiently. You want to keep the RF-1944 in your bag of tricks, because it will generally get you better link quality across a wider range of freqs without modifications.

If you want to know how to make and set up a field expedient dipole, ask me or SSG D (1st Platoon). We both have our slightly different techniques, but I can tell you that I can easily set up a quick low level dipole in under 10 minutes (probably under 6-7 minutes), and I can break it down in under 5 minutes.


Quote:
Originally Posted by Aimpoint View Post
Sending an ANGUS with the 1940 kit at 0200 when there's a time hack (eyes on) is counterproductive, IMO. In addition, security hasn't really been established, and it's noisy as hell... just a bad idea. One day we'll get dedicated SATCOM
I was a LRSD & LRSC Commo chief for over twelve years and this does not sound right. Typically, a LRS team inserts at first dark and does not have a planned window until first light. We used to have teams come up on SATCOM voice to send an ANGUS one terrain feature away from insertion, but over time that was deemed not neccasarry. The guys on the insertion aircraft confirm the team was inserted. Having the team do anything between insertion and sunrise just takes away precious time for movement and digging.

Aimpoint and 69 Harley -

In some ways, you're both right. The unit SOP is to send up the ANGUS report within 4 hours of insertion. There is an argument to be made that it is not 100% necessary and that it takes time away from getting to the NAI and getting eyes on. What you have to keep in mind is that we are a NG unit conducting our training within some time constraints. The typical training mission we run is about 36 hours from insert to extract. The team inserts at last light, moves to the NAI during hours of darkness, gets eyes on by first light, then exfils after last light that evening and is extracted the next morning. If you didn't do your ANGUS report on that first night while moving, when would you get the chance to practice setting up your antenna at night, while at a long halt? Setting an antenna up once during daylight while in the hide site is easy, that is not adding much to your training. During our training, the commo windows are somewhat unrealistically closer together than necessary. The reason for this is to force the teams to set up their antennas multiple times and use the radios and reporting formats multiple times. That maximizes the training value we can get out of a 36 hour mission.

Two other quick points: you should not be doing comms without having security set up first. Long halt procedures start with establishing security and setting out your claymores. If this isn't done, you shouldn't be using the radio. Also, the rest of the team should be at 100% security.

Also, the technique a lot of teams try to use is to get to their ORP within the 4 hour window. That way they can set up security and make comms once instead of twice. It doesn't always work, but it's a good technique if you can do it.

Lastly, Aimpoint, if you go to RSLC, be prepared to do it the way we're teaching it. That's the way they do it (at least as recently as last year), and you might even be thankful you've had all this practice doing it. RTO is a graded position and getting your ANGUS up is definitely part of the grade.

[helicom6]

Are people still looking for information on the PRC 150? Leave me a PM.

[helicom6]

I am confused by some these posts because they have a certain amount of information that would be considered at least secret because posters are using acronyms,along with, theories that can be used by non-subjectives. While this is a great resource for our SF community, I found that using PM's and a secure email to exchange information to be the better school of thought. Just my .02!!