Garey, congratulations to you!!!! We did it!!! I checked C6, it was looking fine, so I tried to move it a bit more hard and saw it was multi-turn! In fact, only then was able to null the CO completely!!!
I hope to catch you on the air with this singing T-4XB! 73 and grazie mille! Frank IZ2OOS 2010/3/22 Garey Barrell <[email protected]>: > Frank - > > Congratulations! :-) > > C6 is also multi-turn. It is a "piston" trimmer, where turning the threaded > adjuster moves a metal piston up and down within a tubular body with the > other "plate" of the capacitor wrapped around it. IF you are able to null > the CO completely, I wouldn't force it. If not, then you'll have to see > what is interfering with the piston under the chassis. One thing I have > seen is where someone got too close to the plastic tube with a soldering > iron, deforming it and preventing the piston from going any further. > Hopefully that's not your problem. > > Let us know what you find! > > 73, Garey - K4OAH > Glen Allen, VA > > Drake 2-B, 4-B, C-Line& TR-4/C Service Supplement CDs > <www.k4oah.com> > > > iz oos wrote: >> >> Hi! Homework complete! >> >> Yes, Garey was correct !!! The RF Output meter was not sensitive >> enough to balance the Balanced Modulator and I think I followed his >> procedure! >> >> I connected a Drake 2-C, with the mute cable and the antenna cable >> connected to the rx output of the T-4XB and then "spotted", so that >> the RX and the TX were at the same frequency. The 2-C was set at with >> the function EXT-mute. Then, with the "Transceive function of the >> T-4XB set at SPOT", I tuned up in the TUNE position on LSB, then >> switched to CW and closed PTT. Then I listened on the 2-C for the >> "suppressed" carrier. Set AVC to FAST, and adjusted the Carrier >> Balance control (10 turn pot) and C6 for minimum S-Meter reading. I >> could see the difference moving the Carrier Balance pot on the RX >> s-meter !!!. >> >> While the Carrier pot can be moved by 10 turns or so, C-6 seemed to >> move by just 90 degrees (a quarter of turn). I didn't want to force it >> as I was afraid to break it. Do you know if C-6 moves just by that >> little? >> >> 73, >> >> Frank IZ2OOS >> >> > _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
