On Mon, 25 Jul 2011 08:36:05 -0400, Joe Pyles wrote: >It's not just the PTO in the TR7 that drifts. On the PBT/Reference board the >are 3 crystal oscillators, 40 mhz, 13.695 mhz, and 8.050 mhz, and they all >move around with temperature. The 40 mhz crystal moves the most and it not >only is part of the synthesizer, it provides the 500 khz reference for the DR7 >board. When you install the X-Lock you control the PTO drift but not the >crystals.
That's a very good point, Joe. Every time I open up one of my rigs, they all seem to be just a :"hair" off. After fully aligning both my TR-7 and R-7A, with the same frequency counter referenced to the same Rubidium standard, they are far enough off from each other after bing in service for a while that people notice that I am "off frequency" if I transcieve from the R-7A. There is an adjustment procedure for that in the R-7 manual that is reminiscent of the 4-Line (pre-"C") alighment. I woulda thunk they'd learned enough that the 7s wouldn't do that.... 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
