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]

Originally Posted by 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.

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]

Originally Posted by 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.

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]

Originally Posted by 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.

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.

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

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/Ant...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..

ASk away.... AL

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