IT'S ONE THING AFTER ANOTHER - In this Part 4 for this 1950 RCA vacuum tube radio, we decide to redo some of the restoration work we did in Part 3 to address Hum and run into more trouble. We also did restoration work on the case, let's see how that turns out! Alas, we have a fumble on the 1 yard line...

In Part 3 for this cool 1950 RCA tube set, we completed the re-capping and replacing out of spec resistors and see how she does. After all that work, something starts to act up!

In Part 2 we took this radio which we just got to play in Part 1 and begin the repair and restoration to make it work properly. This included getting the tuning condenser re-set and the dial cord re-strung.

In Part 1, we identified that this radio had had a lot of work done on it which was not readily apparent and some of it really needs to be corrected. The biggest issue we had was the tuner was set all "cattywampus".

This vacuum tube Bakelite radio has a classic midcentury modern look about it along with a large 8 inch speaker. Very large by comparison to other table top radios! Can we get that tuner deal worked out, and what other things will we find? Let's watch to find out.

See the checklist continued from Part 1which appears when status changes, for tracking what is discovered that needs addressing in Red, followed by Green when resolved.

ERRATA: I noticed later that on some of the Checklists, the Detector tube is incorrectly called the 12SQ12, it is actually a 12SQ7 of course. That is corrected in later Checklists.

NOTE: This is not instruction, it is for entertainment for people like me who enjoy watching projects and the experiences gained. If you attempt to do any of the things in this video you are at your own risk. I am using special tech-bench safety equipment not detailed here so don't take for granted you can just plug these old items in safely without them being checked and repaired correctly. Check out the link below to Mr Carlson's Lab video below.

ACKNOWLEDGEMENTS AND REFERENCES:
[note: am in no way representing how these folks have shown doing these things - I don't even think they would approve.]

Thanks to @hestheMaster and @jimnewman5596 for pointing out my schematic is not the latest rev, which led to confusion about the capacitor within the shield coil. I guess the RCA Service Notes and Sams is better for me than the Riders which I used. Thanks guys.

Thanks to shango066 for championing the approach of "fix it first", before mass re-capping. See shango066 for many examples of that approach.
@shango066

Special thanks to Doug at DERB for the shout-out here:
[ Ссылка ]
@DERB_Seymour_Indiana

Awesome discussion of bench safety including variacs and isolation transformers by Mr Carlson's Lab (highly recommended):
[ Ссылка ]
@MrCarlsonsLab

Modification method for a commercial Tripp Lite isolation transformer for tech-bench use by Todd Harrison, his channel is called ToddFun:
[ Ссылка ]
@ToddFun

Camera: Canon G7X Mark III
Mic: Rode Micro
Video Editing Software: Power Director
Video Editor: just me

свернуть