The problem has been fixed! I'm happy to report that simply adding an OA2 regulator a tube has resulted in a clean signal. However I have noted that the interstage tuned circuit is not resonating properly on 40 m and the drive tuning control has to be set with the capacitor all the way open. Several other users of T 60 rigs have noted The same problem and had to remove three or four turns from the 40 m coil in order to get it to resonate properly.
I'm using those remanufactured FT 243 crystals from AF4K, hi hi. It sounds great now and I just made a contact with the station in Cuba who is running 7 W on 7110 kHz. My Signal report from the T 60 running 38 Watts: RST 599. Best regards - Brian Carling AF4K Crystals Co. 117 Sterling Pine St. Sanford, FL 32773 Tel: +USA 321-262-5471 > On Jan 6, 2015, at 9:00 AM, [email protected] wrote: > > Dear fellow Boatanchor Ops, > > I recently bought a nice looking old Knightkit T60 from a friend in > preparation for > the Novice Rig Roundup coming up in February 2015. > > However, it chirps. I replaced all the fixed caps with Tom's Hayseed > Hamfest kit. No improvement ensued, but great insurance against future > failures. I observe that > the osc plate voltage drops from around 320V to 215V when keyed down. This > being derived from > the same source as the buffer screen supply. I tried replacing the 8.2K 2 watt > resistor which was up around 9K. That hasn't helped either. > > What would you try next? I am thinking about replacing the two tubes, 6HF8 > and 6DQ6B, but that would make it a very expensive T60. I also thought anbout > putting in > a 185v regulator but have my doubts. This transmitter should not chirp this > much. > > 73 - Bry AF4K > > Brian Carling, Radio AF4K > _______________________________________________ > Boatanchors mailing list > [email protected] > https://puck.nether.net/mailman/listinfo/boatanchors _______________________________________________ Boatanchors mailing list [email protected] https://puck.nether.net/mailman/listinfo/boatanchors
