Mathiew, A VHF/VHF system that was local controlled in a portable repeater set-up could be built using the identical circuits you used for the remotes. If you ID the repeater along with the user, it could serve in an emergency. It gets a bit dicey to let the users ID a repeater for long periods of time though, and not recommended for any extended use. As cheap as the simple controllers are these days, inserting one in the system would make a lot of sense. In that case, get one that has the audio de-emphasis built in, like the NHRC-3, and it will output the audio back to the mic input with no problem. The vol/sq high is used as the input to the controller. Use the CAS signal as the carrier input to the controller, and the PTT is supplied by the controller, so no circuitry is required in the radio. Plenty of room to mount one of these controllers where the CTCSS board was removed and wire direct to the terminals you used for the cross-band units. I have seen other controllers in kit form with very basic control capabilities that could be used, but I am not familiar with them.
If you want a really high-sensitivity repeater for your portable, think about separating the transmit and receive and use another cross-band (440 in and 147 out) at the 2 meter transmit site. With enough separation of the input and output sites, you can have a really high-performance repeater without a lot of the problems caused by a portable repeater, like poor sensitivity for receive and low transmit power without desensing the receiver. About the only solution for a portable with a reasonable sized duplexer is to use a wide transmit/receive separation, which means that all your users will have to program a non-standard split to use the repeater. Lugging a full size duplexer around for 600 kHz split 2 meter repeaters would be a bit of a bother. By the way - did you manage to get the repeated audio up to where you wanted it for the remote radios? I think you will remember that we mentioned that an emitter follower could be added between the receive audio which was de-emphasized by the 15K series resistor and the shunt .22 UFD cap. Just add the emitter follower base at the output of the 15K/.22 with the emitter to the 1 UFD cap going to the mic input, with the collector of the transistor going to the +10 from the SAS board. Put a 1K resistor from the emitter to ground. A common 2N2222 can be used, and the loading provided by the MIC input bias resistor will not bring the audio down so much. 73 - Jim W5ZIT -----Original Message----- From: [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tue, 5 Dec 2006 3:12 PM Subject: [Repeater-Builder] GE Exec II, I want to make a portable repeater, is it all the same I recently finished converting some GE Exec II's for crossband operation. Want I want to do is make a repeater from one, in the VHF band. Would everything be the same as when I did the crossband. Will there be any other issues that I might encounter? This is going to be on a VHF unit in the 147 Mhz range. Thanks. Mathew N9LV ________________________________________________________________________ Check Out the new free AIM(R) Mail -- 2 GB of storage and industry-leading spam and email virus protection.
