Motorola 57W

[SpaceAge]

For what it's worth, I did finally test the bulb today and it shows infinite resistance.

[maxm]

For replacing the dial lamp bulb, I recommend looking for NOS USA-made lamps from a company like GE, Chicago Miniature, etc. They are much better quality than the new Chinese bulbs you can buy. I've had some of the new bulbs burn out very quickly, or have the glass twist off the base when installing.

I often find the old bulbs at estate sales, but depending on where you live, they may be tricky to find locally. There are some sellers on ebay offering the old bulbs.

[SpaceAge]

Originally Posted by maxm

For replacing the dial lamp bulb, I recommend looking for NOS USA-made lamps from a company like GE, Chicago Miniature, etc. They are much better quality than the new Chinese bulbs you can buy. I've had some of the new bulbs burn out very quickly, or have the glass twist off the base when installing.

I often find the old bulbs at estate sales, but depending on where you live, they may be tricky to find locally. There are some sellers on ebay offering the old bulbs.

Didn't think about looking for a NOS. I checked and the brand I ordered from Mouser is Visual Communications Corporation. I guess if it dies I'll buy NOS from eBay next time. My neighborhood is too new for anything like this to show up at estate sales, garage sales, etc.

[SpaceAge]

After nearly a week in transit, the parts order finally arrived today so I attempted the recap. I'm happy to say everything went mostly well, and the radio is now reassembled and sounds better than it did before. Here is a before and after look at the underside of the chassis


Here are a few of the capacitors that have been removed.


One minor complication... The leads on the .047uf caps were significantly shorter than the others. Compare them to the .01's to see the difference. I had to add some wire which was time consuming but worked out fine.


As you may recall, the knobs were pretty gross. I cleaned them by soaking in warm water with dish soap, then scrubbing with an old toothbrush. I also used toothpicks to scrape shirt out of the grooves. Ended with a spray of formula 409 to sanitize them. There is a little bit of discoloration on one of them which is probably permanent, but it's hardly noticible.


Cleaned up and reassembled.


So that pretty much does it. I may try to publish a YouTube video of it playing. Thanks to everyone here for all the help and guidance on this project.

[SpaceAge]

I have no idea why the picture links aren't working. Anyways, see for yourself here: https://www.flickr.com/photos/145591...57673579346334

Edit: I realized some of the pictures in this album were private. This has now been fixed

[SpaceAge]

Okay... so I've been having a lot of fun with this radio. It now sits on my desk where I have been running it while doing homework. It's a lot of fun to listen to Christmas tunes on either of the two "oldies" stations I can receive. There's also a station operated by the Lutherans or something that sometimes plays Christmas music. BUT... I have noticed when I turn up the volume past a certain point, it becomes scratchy and garbled. Does anyone have any ideas of an obvious cause? Over Christmas break I am planning to open it up again because I discovered the metal bracket that held the old electrolytic capacitor will actually fit the three replacement caps perfectly, so I'm going to add it to make everything more orderly. But yeah, scratchy audio when the volume is turned up. Any ideas?

[dieseljeep]

Originally Posted by SpaceAge

Okay... so I've been having a lot of fun with this radio. It now sits on my desk where I have been running it while doing homework. It's a lot of fun to listen to Christmas tunes on either of the two "oldies" stations I can receive. There's also a station operated by the Lutherans or something that sometimes plays Christmas music. BUT... I have noticed when I turn up the volume past a certain point, it becomes scratchy and garbled. Does anyone have any ideas of an obvious cause? Over Christmas break I am planning to open it up again because I discovered the metal bracket that held the old electrolytic capacitor will actually fit the three replacement caps perfectly, so I'm going to add it to make everything more orderly. But yeah, scratchy audio when the volume is turned up. Any ideas?

It looked like it had the original 50C5 and it's probably weak. That's where I would start, next would be the 12AV6 or 12CR6. Motorola used the 12CR6 in some of their radios.

[jr_tech]

Possibly the voice coil of the speaker is dragging on the magnet with longer travel (higher volume levels). You can "test" by manually pushing the cone in and out and listening/feeling for scratchy noises. Paper cones can warp over time, especially if high humidity is present.

jt

[Reece]

Great looking radio, and good job. Congrats!

[SpaceAge]

Originally Posted by Reece

Great looking radio, and good job. Congrats!

Thanks! Over the holidays I'm going to follow the suggestions from both dieseljeep and jr-tech to try to get it working 100%.