[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