[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