Re: [Drakelist] TR7
Y'know, I just had that area apart on mine a week and a half ago, but I don't recall the specifics of the mounting. The collector of Q2101 is definitely hot, but it is a plastic encased device with the only exposed metal on the back side, as I recall. Metal hardware on the top side shouln't be a problem. If it were, the rig wouldn't be working at all, as you would have no +10V. U2102 is the 5 volt regulator IC, and should have a plastic bushing under the nut. Although it could be bolted directly to ground, as the tab of the device is common to the ground leg, Drake may have chosen not to do so to avoid the possibility of a ground loop in the 5V supply. If there's no plastic bushing, someone messed up somewhere along the line. 73 -Jim NU0C On Sun, 1 Jul 2012 20:08:26 -0700, k6uo wrote: >I'm trying to get the audio on my TR7 to work properly and making some >progress. One thing >that seems strange, Q2101 and Q2102 on the power supply board have mica >isolators behind >them attached >with metal hardware which defeats the isolators and I can't imagine the >transistors shouldn't be >attached to the heatsink. Anyone know? -- 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
[Drakelist] TR7
Hi All; I’m trying to get the audio on my TR7 to work properly and making some progress. One thing that seems strange, Q2101 and Q2102 on the power supply board have mica isolators behind them attached with metal hardware which defeats the isolators and I can’t imagine the transistors shouldn’t be attached to the heatsink. Anyone know? Thanks, Norm FREE ONLINE PHOTOSHARING - Share your photos online with your friends and family! Visit http://www.inbox.com/photosharing to find out more! ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] R4C Questions
Hi Group I recently obtained a Sherwood upgraded R4C (SN 22xxx), the only Sherwood upgrade it doesn't have is the 2K Upper & Lower SSB filters. It performs very well but it has one oddity. When in SSB mode and the PBT is adjusted Upper & Lower end of travel it varies the S-Meter from S6 middle center PBT to S1 either PBT endpoint. On CW using the 1.5Khz, 500Hz or 250Hz it works like it should or what I'm accustom to. I've corrected many small problems by treating grounds and filter sockets, tube sockets from the topsidebottom side next. It just seems like I'm getting allot of white noise or bleed through from somewhere to cause the SSB mode oddity. Question? How can it tell if this has the T7C version xfrmer?? These Sherwood upgrades were done 20+ yrs ago and this nice condition R4C has sat unused for many years. Perhaps all is typical as I don't have another to compare to. Best 73 Bill KB9IV___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
