I’m working on this SX-62. It appears as I read this that it has a 100 mf electrolytic and a .25 cap in parallel connecting to the pot and a common ground for the tone control.
For a 1948 radio this is in decent repairable shape. I’ve had to splice a wire or two that was mouse chewed with new 23 AWG solid wire covered with heat shrink, checking all the resistors, replacing the electrolytics, cleaning, new power cord with a fuse.
And removing the dead mouse that came with it.
I debated totally pulling apart the wiring harness to put in new wires but decided against that for now.
This came with Sprague caps so I’m leaving them until I see if there’s an issue rather than shotgun replace them.
That cap is NOT 100 uf or microfarads, it's 100 mmf now known as picofarads, it was more then likely a mica cap, rather then an electrolytic, though that is not necessary with a tone control.
Regards
Arran
Thanks for clarifying that. There was a 100 mf cap in there which I removed - hence my confusion. I’m sure I have the right value in my parts box.
Apparently a previous owner “fixed” this with whatever random parts he had on hand. The power supply cap is the wrong value. The other electrolytic is a strange brand which I’m convinced was salvage.
This sat in storage in Michigan for 18 years - not good storage evidently judging from the dirt and rust . I’m taking my time going through this - hopefully that will give whatever moisture is in this a chance to dry out.
<<This sat in storage in Michigan for 18 years >>
The state or the lake?
I've seen these before.
I’m thinking a lake inside Michigan. This came with a dead mouse and his nest. I got this for the cost of shipping. The seller was some flipper who had the idea he’d “restore” it.
I’ve actually seen worse. It has all the original glass intact, a case without any dents.
Have worked on a number of Hallicrafters over the years the resistors will be all good or time to replace them all! Have fun. David
Yea - I’ve restored a number of Hallicrafters and that’s how it goes.
I’m currently checking through the resistors. So far about half are out of spec e.g. 20 percent or more above listed value.
This gives you a sense of this. Given this I’m going to in some cases clip the old resistor close to the body and do a wire wrap with the new resistor . Not sure it’s the best practice but I’m wanting not to break anything on these riveted in tube sockets.
Still working away on this. Decided to replace three tube sockets so did that and now rewiring. Have this old Micamold of unknown value previous owner just stuffed in.
Radio did work briefly but developed a short which I think I have tracked down to an untrimmed wire lead touching the chassis.
Looks like a 680pf. There's a meaning to the white dot but don't remember. Could mean it's a mica cap. Some MicaMold caps are paper.
I think the white dot is a tolerance marker. I just ordered a new silver mica at 680 at 5 percent.
I’ve been rewiring basically the entire audio section of this SX-62. The 75 year old tube sockets were just becoming brittle. So far so good although I’d love to see a good clear photo of this whole section to check my wiring. I dry fit some wires this morning and will recheck them again before I solder.
These new ceramic sockets seem to work well. I’ve been having to splice several of these short old wires and cover them in heat shrink.
With many of those molded Bakelite tube sockets, especially the Amphenol made ones, you can replace a broken terminal rather easily, but you have to desolder everything from it, and then you straighten the terminal to flatten out the little barb, and push it up through the top. The ones in the radio look like Cinch brand sockets, but I think the terminals come out the same way.
Regards
Arran
Thanks. In this case the terminals just broke off even with the base of the socket. No saving it. Plus these were so dirty, greasy and filled with old solder just better to start clean