[Dave Loudin]

Originally Posted by metcalfg

http://www.tvfool.com/?option=com_wr...b7c8ab867e5a8f

Ok, I made an antenna out of coat hangers based on some instructions I found on the web (4 bay?). I aimed it in the right direction. Works pretty good (as good as the 2 commercially made antennas I tried - 1 yagi type, 1 omnidir compact type), but periodically the signal fades briefly and gets little frozen pixellated squares. I have tried with an without 2 different amplifiers.

First point: many of the bow-tie antenna plans derive from a Youtube video that uses too-small elements. There's a long-running thread on a Canadian site devoted to this design that usually recommends these dimensions.

Originally Posted by metcalfg

1. Lot of trees in the area of my yard, but a somewhat clearer view of the sky can be had from the other end of the house. Is it worth the trade-off to get the clearer view though I'll have to add 50 ft of cable?

Use the "start MAPS" option to set your receive location at the different points you're interested in. Zoom in on the Google map (using the satellite option) and move the receive location to each point. You'll see the predictions update below. Be sure to use the correct antenna height, too. Given the noise margin (NM) in your original plot, you've got plenty of signal to work with, so 50 feet should not be a problem.

Originally Posted by metcalfg

2. Is there a significant difference between different antennas. I was thing about trying an Antennacraft® HBU22 or HBU33

Antennas of similar construction should perform the same. The only difference between the two Antennacrafts you cite is a trade-off between more sensitivity in the forward direction against sensitivity in other directions. The HBU22 should work for you. However, the bow-tie design that you can make yourself should work just fine, also.

Originally Posted by metcalfg

3. Is an amplifier an amplifier, or is there considerable variations there, as well?

There are differences! The major design factor is noise figure, which subtracts from the noise margin caculation no matter what. Good commercial designs have noise figures of 2 or 3 dB. Cheapies, often buried in indoor amplified antennas, will have 6 to 10 dB noise figures. You should not need an amplifier with the right-sized bow-tie or the Antennacraft you're considering.

Originally Posted by metcalfg

I care most about WKOP, the local PBS system, which is giving me the most trouble, but not consistently. Some nights it works great...other nights almost unwatchable. I'd really like a few major broadcast networks (I like NBC), but other than that, I don't really care

WKOP transmits on channel 17, the low end of UHF. If your current antenna has 7" whiskers, then it's too small to perform well on 17. Use the bigger design, or spring for the Antennacraft. You might not have to use all that coax. Good luck!