buying a good used GMRS repeater for neighborhood watch

[Logan5]

I have seen this type antenna in a junk pile more than 12 years ago. if I had known then. what i know now.

[PastorGary]

Even a single stack such as that will give you just under 6dbi gain.  With a 50 watt repeater and figuring a small amount of line loss, that's still an ERP of around 109 watts or EIRP of 179 watts.  Check with JohnE concerning a coverage area  - that should be easy to calculate with his software because your part of Florida is nearly flat. 

 

 

Good luck on your project!! 

[Billy]

Have seen used on ebay. Still pricey.

[JohnE]

you have LMR 400 witch IMO is a little better that you average 213 cable. losses at 450Mc by the book are 2.5db/100'. in the grand scheme of things you total losses (duplexer/line/insertion) will be  ~2.5dB so any antenna you can get to get over that would be good. I personally use fiberglass sticks w/5dB gain typically, they can be had for $100.

on control's I use 5 or 6 element yagi's.

one of these yrs I'll put a set of yagis in a stacked array like the folded dipole's just to see how it will work for s&giggles. one of my RF engineer friends thinks I'm out of my mind, but hey there nothing wrong w/experimenting.

link to the propagation software http://lrcov.crc.ca/main/

[Logan5]

Logan5,

If you have not bought the repeater for $229.00 checked by a Motorola technician let it go buy.I bought one several years ago and had nothing but head aches from it and also had a friend buy one a few weeks ago and it is not right either,programmed wrong CW ID doesn't work.The only reason the bought it was for amateur radio and it will not work in many different ways...William

Thanks William, I did end up buying the Motorola. it arrived this morning, I connected it to a pretuned duplexer I had already ordered and I like it better than the Uniden. mostly because it's small and light weight. the technician/seller claims it's a 30 watt set up, and I forgot to ask if it's a 25 watt radio with a boost. or if it's a 40 watt radio turned down to 30. someone mentioned this radio does not come in 30watt's I will have to ask, but so far I am getting even better range than the uniden. I have FTL600 and FTL675 but only have one up at a time.

[JohnE]

do us a favor

measure the output before and after the duplexer, I'm curious about how much loss it has. if its a good tune your losses will be ~6W based on the 30W its suppose to do.

this was one of those Chinese filters ,right?

[Logan5]

nope, it's an RFS same company as cell wave out of Marbouro new Jersey. The other duplexer I have is an actual Cell wave and I found a place that tunes them for 45 bucks here on the site.

[JohnE]

good. those should have a loss of 1.5dB sometimes less and around 75dB of isolation. you'll be good to go w/those.

[Guest spd641]

Logan5 good luck with it,I just know what I was told and I have bought from him also and was not satisfied but it was the radio/WT combo,should have known better....William

[Logan5]

Thanks again William, I will find another person to tune the duplexer then.