On Tue, 27 Sep 2011 07:41:03 -0400, ian parkinson wrote: >I saw a Mod for the TR 7 which involves cutting some pcb tracks for all band >tx option..it certainly would be great to operate on the 30 metre WARC band. >Any thoughts over this mod is it too risky ??
The only real risk, per se, is that you may accidentally transmit somewhere that you shouldn't and the communications authorities will notice. However.... There is a right way and a wrong way to do this mod. Surprisingly, the published method from Drake is the wrong way to do it. It does give you all band allband transmit as described, but the method for doing so has the side effect of disabling the out-of-lock (OOL) transmit inhibit signal from the PLL. This could allow you to accidentally transmit out of band if the PLL happens to unlock for some reason, and also prevents G4ALG's mod to eliminate the TX spike when power is turned on from working. I have published a method that preserves the OOL signal and involves two trace cuts on the old version Digital Control board. I haven't worked it out for the newer version board yet, not having one at my disposal, and there seeming to be no interest. Most people seem to go with the bad method, despite explanations as to why it is not a good idea.... 73 -Jim -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! "Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime." HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org _______________________________________________ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
