Re: S-85 refurbish: I've got a problem during the RF alignment of bands 1 and 2 - trimcaps don't peak!
¿ªÔÆÌåÓýHi jim, ?RE? C4 and C15 both peak nicely (by ear) at 1.4 MHz ???always good to have a verification? ? ? After looking at the S40B, we might just have to resort to the gimmick idea, but with the capacitance being between the front and rear of S1B Possibly enough capacitance? PS I tried to make this so most others could understand my thought. ? From: [email protected] [mailto:[email protected]] On Behalf Of JThorusen
Sent: Friday, February 14, 2025 4:48 PM To: [email protected] Subject: Re: [HallicraftersRadios] S-85 refurbish: I've got a problem during the RF alignment of bands 1 and 2 - trimcaps don't peak! ? Greetings to the Group: ? I have been following this thread for awhile and I thought I'd add what data I can.?? I have my S-85 apart on the dining room table and I can state the following using my VNA as a signal source: ? 1.?? The RF amp (6SG7) is definitely in the circuit.?? When this tube is pulled, the signal goes away. 2.?? C4 and C15 both peak nicely (by ear) at 1.4 MHz. ? Unfortunately, the area around S1B is very crowded and visibility is poor.?? As far as I can tell, the unit is wired just as the schematic states; I'm sure there is a divergence somewhere as the circuit cannot function as drawn, but I cannot find the difference. ? This is probably not much help, but it is the best I can do at this time. ? 73, -- Jim T. _._,_._,_ -- don??? va3drl |
don Root