PRC-150?

[glebo]

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

[bravo22b]

Originally Posted by 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.

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]

Originally Posted by bravo22b

...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]

Originally Posted by bravo22b

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]

Originally Posted by 69harley

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..

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]

Originally Posted by 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

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

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

[69harley]

Originally Posted by 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

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.

[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?