As I recall, the gain pot on the V1 predriver was problematical; Drake service notes basically said to leave it alone unless you absolutely have to adjust it. Other than that, I'm just making a wild guess that the V2 board may bhave been a cost saving redesign. Someone else may have more info.
When I had strange oscillation problems (not to be confused with the "40-Meter oscillation" problem in V2 boards) in my rig, it turned out to be leaky driver transistors on the PA board. You can read about my adventures here: http://zerobeat.net/drakelist/smf/index.php/topic,224.0.html 73 -Jim NU0C On Thu, 14 Jun 2012 21:17:30 -0500, Lloyd2 wrote: >I am working on a TR7 that the transmitter PA breaks into oscillation every >time the it is keyed. Is there a design issue with the version 1 predriver >that caused Drake to change to the version 2 board ,or should I rule it out >and focus on the PA itself? > >TNX, >Lloyd - K4HWB -- 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 [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
