Terry, First check the TR7 power supply board for exactly +10v. This is the rightmost pot and you can measure the 10v next to it on the top of a resistor as I recall. Go to wb4hfn.com and you should find info on where to measure this. This is not the best place to measure and adjust, but easy for starters. The +10v pot is easy to bump and knock off. Certainly, ... don't touch it until you've measured the +10v. When it is off (more or less than +10v), this can effect most every circuit in the radio. Resetting to +10v might solve the problem in the short run, but any change to this setting usually requires a full alignment. The 10v is properly set by taking measurement on a trace on the motherboard. You'll need the service manual for this one. And a high quality DVM.
While you are looking at the power supply board, look down about half way to the little transformer and make sure it is all in one piece. Sometimes the core comes loose and falls away. This makes for all kinds of stability problems, not to mention causing an "unlock" to the freq. display. If the +10v supply is spot on, I'd suggest a full alignment. Again, you'll need the service manual for that one. I'm sure others on this list have far more experience than I regarding a specific problem on 160, so I'll defer to their comments. David Wd9cmd ----- Original Message ----- From: [EMAIL PROTECTED] To: [email protected] Sent: Monday, December 08, 2008 8:51 AM Subject: [Drakelist] TR-7 Frequency Problem My TR-7 has developed a frequency problem. When turned on with the bandswitch on 160m, the frequency readout showed a frequency of 17600-17800 Khz and was jittery. After warmup of a half hour or so, it would start working and and show 1870 Khz like it should. Now, it doesn't show 1870 khz at all and stays in the 17600-17800 range even after warm up. Neither the RX or TX is working. However when I push the RCT button and go to my R-7 for frequency control, everything is working correctly and I am on 1870 Khz and the RX and TX is fine. When I switch to transmit the TR-7 readout shows 1870 Khz. When I go to RX then it goes back to 17600-17800 Khz. So where should I start looking in the TR-7 to find the problem? Is this a known problem that someone else has experienced or a new one? Any help someone could offer would be appreciated. Terry, W8NJR ------------------------------------------------------------------------------ Make your life easier with all your friends, email, and favorite sites in one place. Try it now. ------------------------------------------------------------------------------ _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
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