How to install the RX antenna connection on a MVP
By Kevin Custer W3KKC

Concept:  When building a repeater from a MVP mobile radio, a separate receiver antenna connection must be installed.  The receiver antenna connection is added by drilling a hole in the back of the radio set and installing a pigtail with a quality SO-239 type "PL" or UG-58A/U type "N" chassis connector and a "hood" referred to as UG-177/U.  I use RG-400 or similar coax for the cabling since it is double shielded and has a tough teflon dielectric.  This method provides a totally shielded connection that will allow the repeater to work without desense.  The original antenna connection becomes the transmitter RF output antenna connection.

Procedure:  Remove the outer cover from the radio if you haven't already.  You will need to unplug the short RF cable from the antenna relay to the receiver RF deck.  Don't throw the jumper away as you may want to reuse one of the RCA plugs from this jumper for your new antenna connection.

Drill a 1/4" hole in the rear panel beside the original SO-239 antenna connector, about 1/2" toward the center of the radio, making certain to leave sufficient space from the edge of the panel to allow the outer cover to be reinstalled without covering the hole.  Using RG-142, RG-223, or RG-400, make a jumper cable about 1 foot long and solder a RCA Plug on one end.  Leave the other end flush cut for the time being so the wire can be threaded into the 1/4" hole made in the back of the radios rear panel.  Connect the RCA connector to the receivers front end casting and tailor the wire so it runs nicely to the hole keeping the wire away from the SO-239 transmitter connection as far as possible.  You should have about 5 or 6 inches of coax sticking out the back of the radio set.  Now install a quality SO-239 type "PL" or UG-58A/U type "N" chassis connector and a "hood" referred to as UG-177/U to produce a totally shielded connection.  4-40 x 1/4" bolts are used to secure the hood to the connector.

This added wire and connector will serve as your receiver antenna input connection.

Added receiver RF connection

RX coax out the back - Note clearance to 
cover and hood on RF connector.

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