Servicing Hallicrafters SX-100 Mark 1B Shortwave Receiver with bad Trimmer Capacitor

In this video, my use of the radio found an unacceptable popping noise at the upper end of Band 3 and a badly misaligned Broadcast Band Oscillator Coil. I replace the Band 3 RF trimmer capacitor and realign the Broadcast Band Oscillator Coil.

[@Backtothefutureradios]

Enjoyed the video Albert! Last I looked Dalton is still listed as a go..... I could see a boneyard at a minimum......Take Care-Larry

[@micjam1986]

Hi there, I was wondering if hallicrafters tuning caps are isolated from the chassis? I'm working on a S20R that has been worked on previously... presently it's sitting on metal washers. Thanks.. mic

[@i82996]

Hello Mic. I don't have an S20 schematic but I looked on the SX-32 schematic, which is as early as I have, and the tuning caps are directly connected to ground. All the radios I worked on, the SX-71, SX-99, and SX-100 did not electrically isolate the tuning caps. Only the SX-71 had non-metallic washers (but the screw went directly from the bracket to the chassis), and the washers provide mechanical isolation to keep tuning caps from experiencing vibration from audio sound or other sources; that radio was a cut above in quality. By the way, you may or may not realize it, the stator on a tuning cap is electrically isolated from ground and connected to the tuned circuit. The bracket and rotor assembly are grounded. Blessings and 73, Albert

[@micjam1986]

@@i82996 I was focusing on the mounting hardware but removing it I see it had a soldered braided connection to the chassis and it shows its the stator that is isolated..interesting! Thx for your time and input!!

[@i82996]

@@micjam1986 If you could send a "clip" image of the relevant part from the schematic I am interested. Use the "business email" on my channel. Albert

[@micjam1986]

@@i82996 I will try