Feel like a little kid again! First hit on repeaters

[WRTC928]

17 hours ago, Radioactive said:

Be careful with long runs on gmrs. The loss is high at 467 and unless you have some good LMR or hardline then the cable loss will outweigh the gain of elevation. 

That is something to keep in mind, but IMO, the elevation will almost always be worth it, even with the coax loss. Obviously, that depends upon a number of factors. Let's say you have a Comet 712efc antenna (6.85 dBd gain) on a 50' mast and 50' of LMR400 coax on a 50 watt radio or repeater. You'll lose ~28% of your signal at the antenna feed point. If you raise the antenna another 50', you'll lose 48%. That sounds like a lot, right? But let's factor in the antenna gain. With 50 watts input and 6.85 dBd gain, you'll get an effective radiated power of 174 watts with 50' of coax and 125 watts ERP with 100'. How many watts do you need? Will 49 watts make a significant difference in performance? I doubt it. On the other hand, another 50' of elevation will probably make a very large difference in the range of your radio/repeater. If I could get that antenna up to 200', the ERP would be 64.6 watts. I'll take that all day every day over 174 watts at 50' elevation. WW2 pilots talked to ships 200 miles away on 14 watts. Every day, people talk to the International Space Station on a 5 watt HT. 

It's easy to make too much of the coax loss. Get the antenna as high as you can, then buy the best coax you can afford and quit worrying about it. 

Coax loss calculator

[WRTC928]

18 hours ago, WSKY567 said:

Pretty much decided to go with Times LMR-400.  1/2 inch helix is just too costly and to difficult to manage for the added benefit.  Right now I'm studying more on ferrite chokes to understand best placement etc.  I will have one horizontal run of about 6 or 7 feet, a vertical run of about 20 feet and another descending ~30° run down a roof line that I am guessing will be about 15 feet including drip loop at the bottom of the antenna.  I'll be able to attach to truss frame for stability.  

With 42' of LMR400, you'll get about 25% loss for 37 watts (assuming you're using a 50 watt base unit) at the antenna feed point. A good antenna will get you out with plenty of power.