On Sun, 8 Feb 2009 19:23:52 -0500, David & Chris Drake wrote: > >Other issues: I had tweeked the S-meter some, but still reads high. I've >noticed at least 4 S-units higher than my Omni VI+ and about 5 S-units >higher than my TR4C which I think reads a bit low. On Calibrate, CW, on the >null, its 20-30 over.
I just went through S-Meter troubles on two units. My problem was the opposite, though - Drake suggests that a properly calibrated S-Meter circuit will read S-9 at 30-50 uV, and I was seeing more like a couple of hundred. In addition, there was quite a difference in meter readings and apparent sensitivity between my TR7 and R7A, even thouugh the actual measured numbers were very close. There are several changes to the S-Meter circuit that Drake made over the years, as well as variations in the alignment procedures. I've been meanining to go back over my notes and compile them into something sensible about what I ended up with. There's a document floating around, I think it's on the Drakelist web site and maybe WB4HFN's web site, about "factory alignment" of the TR7 - this may be helpful. In the meantime, I'll dig out my notes. Do you have a calibrated signal generator? There are some anecdotes floating around on the web, probably in the Drakelist archives, about typical S-meter readings from the calibrator - although I never really put a lot of stock into such reports, they may be helpful to you as well. >On the plus side, .....the TR-7 receives great, had very good transmit audio >reports, and A,B,C tests between the 3 radios are quite amazing. Welcome to Drake. A properly working TR7, whether or not it should be characterized as "amazing", is a standout. This is why I take my TR7 out to our club's Field Day every year to run 20 fone - to prove a point. 73 -Jim -- Ham Radio NU0C TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://radiojim.exofire.net http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
