[mtownsend]

Originally Posted by Dick

1. Antenna – Radio Shack, Model? – Bought 17-18 years ago but in excellent condition as it was in the attic.

The VU-90 XR is an OK antenna. It's a relatively small full band antenna that does what it's supposed to. You are getting most of the channels that are within range of your location, but the problem is that it's not stable 100% of the time. This means that you could do better with some more signal margin to keep you off that "digital cliff". More margin will give you more room for variability caused by wind, trees, and weather that inevitably occur.

One way to get that extra margin is, of course, to get a bigger antenna. An antenna like the Winegard HD7084P or HD8200U will get you significantly more gain across the board and should give you much better stability on all your channels.

2. Mast mounted amplifier – Antenna Craft Permacolor Model 10G212

This amp has a Noise Figure pushing 3.5 to 4.0 dB, which is not quite as good as the 3.0 dB or less that you can get from the competition. The Antennacraft model 10G202 has better Noise Figure specs, and so do comparable offerings from Winegard and Channel Master.

However, switching to a better amp will only give you about a 1 dB improvement. This means that yes, it's possible to do better, but the gain is not very significant. I would recommend that you try a better antenna first. A big antenna will probably give you a ~5 dB improvement on most channels, and this will probably give you the added stability you need. If you still think you need that the extra 1 dB of improvement with a different amp, then you can always add it later.

3. Downlead – RG-6, RCA, 35 feet

That's good. The only word of caution I would add is that you need to make sure that all exposed connections are protected from the elements. You want to make sure that all moisture stays out of the cable and connectors because it doesn't take that much water to kill all your signals.

I'm would like to know in what order to try improvements. Easiest would be a different amplifier. Specs for the one that I have list a 50-890MHz frequency response and 30db gain. Would the CM 7777 do better?

It's my opinion that you'll get much more bang for the buck by getting a bigger antenna. The choice is up to you, but the Antennacraft amp that you have now is not that much worse than the CM 7777 or any other common amp. There are some more expensive very low Noise Figure amps (closer to 1.0 dB) that would give you a net improvement of about 3 dB, but that's still not as good as the gains you'd get from a good antenna.

Another option may be to gang another antenna. What would be recommended, do they have to be the same, how far apart and which should be on top?

If you gang antennas, you can almost gain 3 dB for every doubling of antennas. In all cases, you should only attempt this with identical antennas. Given the fact that you're starting with a VU-90 XR, you can gain a lot more than 3 dB from just a single antenna replacement.

I usually don't recommend resorting to multi-antenna arrays unless there are no other options. To do so requires learning a lot about constructing the mounts, connecting the phasing lines, and a whole slew of problems related to tuning everything.

A neighbor a few miles away recommended a CM 4228, but I’m not sure how good this is for VHF and since it measures 35 or 40" vertically, it might preclude the option of ganging a separate VHF antenna.

You are right to suspect the VHF performance of the 4228. It's VHF performance is actually lousy. Many people try to get away with a UHF-only antenna if they only have one or two really strong VHF stations to deal with, but I'd rather get the right antenna for the job. It's kinda out of the question for your situation anyway because your VHF stations are too weak to even have a chance with the 4228.