Repeater to be installed.

[antnee1069]

Hello

I am about to buy a comet ca-712efc antenna and install it about forty up in a tree.It will be used as a base station until I get a Repeater up this summer.

I have a number of questions

1) what should I use as cable? About a 75 foot run

2) lightning arrester ? Going to put this in a plastic box on outside of house. ( like cable and phone company does) to protect there splitters.

3) How do I ground the antenna ?

4) I want a 50 watt Repeater. What do you recommend? Hopefully after all is installed I'll get 40 Watts out the antenna!

Recommendatioñ please

Thank you

Wqww770

[n4gix]

I have that exact antenna installed on my roof for my repeater. You can see it in the right picture below on the left side (closest to the front of the house).

 

I installed 60' of 1/2" Heliax feedline to allow for future relocation to a taller building.

 

There is a 12' copper ground rod driven into the ground near the service entrance in my front office. All feedlines from the antennas are terminated there into MFJ-270 lightning surge protectors mounted on a 12"x12" copper plate. This plate is bonded to the ground rod with solid copper wire. The entire assembly will be mounted in a weatherproof box similar to what you are planning to use.

 

I have a Bridgecom BCR-40U repeater currently in use and am still in the process of tweaking the antenna system and transmit power to maximize receiving range and lower desense of the receiver's front end. 

 

http://puu.sh/nD77M.jpg

[ASRM]

Search eBay for Vertex VXR-7000's or the Kenwoods, both are decent repeaters. I was on the more watts, better range but honestly you will realize little difference between 20 and 40 watts. I was able to snag a 7000 with duplexer for $700. It looks new and no scratches or anything.

 

I was using the same antenna as you on the comet (if I had to do it again I would go Laird 6DBD instead as it's better built. I have heard bad reviews though?)

 

We went with 60 feet of 1/2 heliax and mounted on a 30 foot telescopic pole and 10 foot above the porch for a 40 foot height. Our range was okay but knew I needed to get 60-80 feet up to get over the pines and trees once they leaf out. I expected my coverage would suffer come this summer.

 

But to be honest it gave us about 90% coverage with mobile for our AO and receive on portables to know we were calling each other.

 

Height is going to be the best thing you can do (Zap and others have drilled that into me) and they are right. Look into the highest point in your area and then see if you can get 60-80 feet up from there. You won't be sorry. If you know of any HAM's with a tall tower you might try to get space on their tower, but use a more commercial grade antenna (the Comet is not a long term solution IMO).

 

Enjoy though, GMRS as a communications tool is great, I am slowly getting my daughter and family as well as brother on my repeater and looking to get some good friends as well (with a license of course) to also get on the system. Our system is for SHTF and backup/cost savings on cell phones. AND for FUN!

[Logan5]

a 10 watt repeater at 100 feet, is 10X better than a 100 watt repeater at only 10 feet. Height is King.

[zap]

a 10 watt repeater at 100 feet, is 10X better than a 100 watt repeater at only 10 feet. Height is King.

Line of sight. UHF in the 460 range is roughly LOS range plus 5-10%.

 

Money is better spent on receivers, antennas and location versus power amplifiers.

 

Coming from a guy who's shooting 500 mW 19 miles at 5.5 GHz and still delivering 60 Mbps over it…

[ASRM]

Line of sight. UHF in the 460 range is roughly LOS range plus 5-10%.

 

Money is better spent on receivers, antennas and location versus power amplifiers.

 

Coming from a guy who's shooting 500 mW 19 miles at 5.5 GHz and still delivering 60 Mbps over it…