[Hallicrafters] Instability Issue on My SX-111

[Jerome Wysocki]

First of all, a sincere "thank you" to the several replies I received in trying to loosen frozen slugs in the the RF coils of my SX-111. I was cautioned to be careful if I used WD-40 on the slugs, for fear that it might chemically damage the coil form material, so if I did, use the smallest drop possible.

I also got good advice on alignment of the 50.75 Khz IFs. Thanks to the folks who responded to this issue. I will soon try these techniques.

Meanwhile, I VERY CAREFULLY freed up the alignment slugs with WD-40 in a syringe and needle, and a metal wrench. I got the slugs finally to move, so I then used the appropriate plastic hex alignment tool and did the alignment successfully, but the slugs then froze up again. I hope the alignment holds, as I'm not sure the coils would survive another such treatment. This was literally a last ditch effort to save a badly rusted receiver from turning into a parts rig.

I dealt with remaining chassis rust issues, and re-capped the receiver. Voltage and resistance checks were all within acceptable ranges. The resulting sensitivity on all bands was phenomenal. The only outstanding issue is instability on 15 meters, only. 

I tried everything I could think of to relieve this instability problem. The band switch was carefully cleaned with a few drops of DeOxit, on the switch contacts, only. Examination with a magnifying glass showed no sign of malfunction of the bandswitch contacts.

All RF coils show electrical conductivity, so no breaks occurred. Except for the instability problems on 15 meters, the set is performing in a phenomenal manner (without further tweaking of alignment of the 50.75 KHz IF, which will be addressed, soon).

Have I overlooked anything? Obviously something is still wrong, or the problem would not exist.

Thankful for any ideas out there!

73s

Jerry Wysocki, KC9JXE

Sent from my iPad