Sonora 50s metal portable

[bandersen]

It was unmarked. It made more sense to have the 200uF closer to the AC line where one end connects while the 140uF hooks up to the seleniums on the right. I bet they would have done it that way originally if there was enough room.

[dieseljeep]

Originally Posted by bandersen

It was unmarked. It made more sense to have the 200uF closer to the AC line where one end connects while the 140uF hooks up the the seleniums on the right. I bet they would have done it that way originally if there was enough room.

I should've said that, I would've done it the same way.
It was great that the terminal strip was there and it turned out, without having to install another one.

[bandersen]

I finished replacing the last of the electrolytics tonight. This time it was an Astron three section and I did add a terminal strip.

[dieseljeep]

Originally Posted by bandersen

I finished replacing the last of the electrolytics tonight. This time it was an Astron three section and I did add a terminal strip.

It's amazing how much interest this set generated. Sometimes, you get satisfaction, getting back to the basics. Wait until you get the set working, with good picture and sound and unplug it. They make the strangest sound, when the caps discharge. You don't hear it, when you shut if off with the volume control. I never heard it on any other make, except Trav'lers.
BTW, the tuners are made by Sarkes Tarzian, according to Sams.

[bandersen]

I'm enjoying working on it because it's something different. I have more Admirals, Motorolas and RCAs to get to and this is a nice break. It's also nice that it matches the Sams service info perfectly

I just finished recapping tonight and the set has really opened up with the much smaller new caps. Check out this comparison.

At the top is the original 0.5 uF @ 200v cap.

Below that are

0.47 @ 630V
0.47 @ 400v
0.47 @ 250v

Amazingly, the smallest one at the bottom is a new line from Panasonic - 0.47uF @ 450 volts!


Here's one of the two green 1N60 germanium diodes. This one is used in the sync circuit. The other is a detector hidden inside an IF can. I hope they're still good.


This was the most annoying cap to get at. I had to bend back some metal tabs and unmount the contrast control to gt at it.


The horizontal wave shape coil was damaged but some epoxy cement fixed it right up.


So here it is just about done. Tomorrow I'll recoat the flyback and start putting it back together. I had to order a couple oddball tubes types that should be hear in a few days. Soon I hope to hear that strange sound you described

[bandersen]

This has to be the smallest flyback I've encountered so far. The wire gauge is pretty thick though. Perhaps because it's an auto-transformer ? Meaning that there isn't a separate primary and secondary.


I recoated it with RTV-133 silicone smoothed out with a paper towel dipped in isopropyl alcohol.

[dieseljeep]

[QUOTE=bandersen;3090167]This has to be the smallest flyback I've encountered so far. The wire gauge is pretty thick though. Perhaps because it's an auto-transformer ? Meaning that there isn't a separate primary and secondary.


I recoated it with RTV-133 silicone smoothed out with a paper towel dipped in isopropyl alcohol.
Is the RTV-133 available at home centers, or do you get it from one of the electronics distributors.

[bandersen]

No, it's pretty expensive stuff ($65 for 10 oz!) and few places carry it. It's also rated for 20kV / mm and gross overkill. I'm sure there are less expensive silicones that would work just as well.

[bandersen]

I found the service info for the Airline version on Ebay. The knobs are different, but in the same location.

[Phil Nelson]

That location in Minneapolis is still a TV service shop.

Phil Nelson

[bandersen]

Cool

I tried turning the controls at the back and found that one is frozen and the other two are crusty. Luckily, some DeOxit fixed them right up Some tubes I ordered haven't arrived yet so I'll just have to be patient and wait to power it up

[dieseljeep]

Originally Posted by bandersen

I found the service info for the Airline version on Ebay. The knobs are different, but in the same location.

That's the 17" model, the one I worked on more often.

[bandersen]

My tubes finally arrived As soon as I get the yoke wired back in I'll fire it up.

[kvflyer]

[QUOTE=bandersen;3090629]My tubes finally arrived As soon as I get the yoke wired back in I'll fire it up.

Gosh Bob, as hard as we try, do we ever have all of the tubes that we need? Seems as though another orphan set shows up at the door and it needs yet another different tube!

Great thread and thanks for keeping us informed.

[bandersen]

I have a few thousand tubes up in the attic, but very few 0.45A series strung type tubes.

The first power up was a mixed bag. Horrible buzzing sound out of the flyback area and no HV. So I popped of the HOT plate cap lead and fiddled around with the tuner. Eventually, I got some halfway decent sound. Next I'll double check my wiring the the horizontal area. I hope it's something simple.

First though I need to wrap some presents.

BTW I do hear that weird sound when I power it off