WRTC928

I'm curious about why you want to do this.

As I said, I've seen houses wired with aluminum wire and secured with steel screws without any significant corrosion. Granted, they aren't exposed to the weather, but they carry a lot of current. I'm not saying it doesn't happen and I'm not going to start randomly screwing dissimilar bits of metal together, but if Comet uses stainless steel radials screwed into an aluminum base, they must not be too concerned.

That makes sense. If three radials can provide a ground plane, expanded metal should work as well or better.

My radials are on the way from Comet. I hung it from a tree and ran a few tests using my improvised "mystery metal" radials. I think I'm going to like this antenna. I had a lot of work to do to get my deck ready to support the mast, but I think I have it ready now. I can raise the antenna as soon as the radials get here. Well, when I also have someone to help me. I can raise it with a rope using a tree branch as a pully, but I need someone to guide it and secure the clamps while I hold it up.

But then I wouldn't get to watch my pitbull bite their leg off on my surveillance cameras.

The one in Oklahoma City appears unused, but I'm trying to breathe some life back into it. The problem is that people ignore it because nobody uses it, but if everyone ignores it, there will never be any activity on it. I do know a guy who said he and his wife use it to stay in touch when they go to the state fair in the fall, so I guess it isn't completely devoid of life. I throw out my call sign every time I'm within range but haven't gotten a response yet. However, Tulsa has four 1.25m repeaters which get quite a bit of use, and I travel there fairly often, so I want to have that capability.

Since it seems to have worked for you, I'll give it a try. It's the only antenna I have that has good readings on 2m, 70cm, GMRS, MURS, and 1.25m. It has good signal on 70cm, GMRS, and 2m; I've never keyed up on MURS since I had a pair of MURS radios about 12-15 years ago. It would be convenient if it worked on 1.25m, because my car has limited real estate for antennas. I could have one antenna that did it all. On the truck, I have 3 antenna mounts, so it's no problem to have one antenna for GMRS/2m/70cm and another one for 1.25m.

The only reason I don't run the 2x4 on my truck is that it doesn't like the very limited ground plane I get on the back of the bed. It works like a dream on the roof of my car, though. It's probably the most versatile multi-band antenna available. Mine even shows excellent SWRs in the 220 MHz band. A good SWR doesn't necessarily mean it will transmit well on that band -- the ability to transmit is dependent upon the electrical and physical characteristics of the radiating element -- but it does mean that if I try it, it's very unlikely to damage my radio. I likely will try it sometime just out of curiosity.

TBH, I'm not sure. It has that dull sheen like aluminum, but that could just be the finish. I don't have a magnet handy, but a lot of stainless steel isn't very magnetic anyway. I think the whole "dissimilar metals" things is a bit overblown anyway. Cars and motorcycles bolt aluminum to steel all the time. If it were a part that carries a current, it might be different, but I've seen lots of aluminum wire secured to an outlet with steel screws for decades without any issue, so maybe not even then.

I'll recheck it when I have the antenna stood up. I hung it a few feet off the ground for the initial test. I wanted to be sure there wasn't anything to address before I got it 40' in the air.

That's true, but the Comet radials are stainless steel, and so are my temporary substitutes. Comet apparently doesn't think the stainless steel/aluminum interface is a problem. It may be a slightly different composition of stainless steel, but I doubt it's enough to cause problems before Comet sends me some. Meanwhile, I'm doing some testing and trial runs. At any rate, Comet isn't kidding when they say "pre-tuned". SWR < 1.2:1 across the entire GMRS band.

Access is just a matter of tipping the mast up and securing it to a post with hose clamps. I just now emailed Comet about the radials. In the meantime, I'm going to stand it up and do some tests with the improvised radials. It will be easy enough to tip it back down and change them when the "correct" ones arrive.

The rods I got are also stainless steel. I'm going to email Comet, but I'll use what I have until the new ones arrive.

I'm of the opinion that on 2m/70cm, anything more than 50 watts is just wasted, with perhaps a few exceptions under very unusual circumstances.

There aren't any buildings in the way.