Sunday, July 17, 2011

EFJ Low Power Repeater Enclosure

Long story short…  I saw an E. F. Johnson-based mini-repeater up for bid on Ebay several years ago and got it for $130 shipped.

The receiver and exciter are from an EFJ UHF repeater.  Even though the enclosures look like complete mobiles, only half of each is in each enclosure.  An RC100 controller handles the ID, etc., and a Phelps-Dodge mobile duplexer rounds out the mix.  The original freq. was 444.575 which coincided with the Knoxville RACK repeater so I got a couple of crystals from ICS and soldered them in.  I tried to align the transmitter but in the end, Henry, WB4IVB aligned the whole shebang.  I actually have a 100 watt EFJ amp to go with the repeater. However, I sold the higher power set of duplexers and will have to find another set before the amp can be used.

SAM_1323 (Small)

An empty McDonalds fry container is applied to ward-off evil spirits and repeater gremlins.  The trans-fat residue does the trick.

SAM_1321 (Small)

The enclosure is an outdoor cable tv box you see adorning many power poles.  W4TEY found it at the Morristown Hamfest a few years ago and generously donated it to the cause.  It’s vented but in a way that helps keep water out.  The top portion has plenty of room for the repeater, controller, duplexers, and power supply.  A small fan would help but at 20 watts out may not be necessary with a commercial exciter.

Right now, I think the best use of this repeater would be at a medium profile site with a couple of beefy deep cycle backup batteries backing up the when PS.  If paired with a high-gain antenna, this modest set-up could really get out and be available during power outages.

I set up the Diamond 718 temporarily at the house to give it a whirl around town.  We’ll see how it goes.

SAM_1325 (Small)

SAM_1326 (Small)

Steve, W4HKL

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