Sentinel Tabletop

Hi Everyone,

A few months back I bought my first tube radio, a Zenith K731. I'm glad I started with that particular radio as it sounds great, and does a real good job pulling in stations. Shortly after buying her, I found your forum and put up a few posts about the radio, seeking general information and thus I was hooked on radios. I'm up to 12 tube radios now, and have a few more on the way. I once again have questions, and I am hopeful that some of you can point me in the right direction.

Like my first radio, the K731 most of my radios are not restored and still have the original caps and resistors inside. The K731 has gotten a lot of play time, and remarkably still sounds perfect, no hum at all, and still a reception champ (although not quite as strong as my Superadio III - a guilty pleasure of a radio that lets me tune in C2C on Fridays when it's not on in my area). The other radios, not too much play time. I have reached the point that I am ready to learn about restoring radios and want to get these old gals back up to full speed. I'm going out to buy a soldering pencil, and a multi-tester this week, and will begin doing the research on what parts I need to buy to repair these radios. I must admit, I have no soldering experience, and have never attempted anything like this before (I do have tons of patience though, so I think that will make up for my lack of experience). Any basic tips to start? Am I getting in over my head?

I also have a few specific questions, and would like to detail the radios I have, and their present condition to see if you could advise me on which one to start with (although I think I am going to start with the Sentinel as I basically bought it for that purpose, but it may end up needing more work than the others after todays little experiement).

1. Zenith K731 - Simply put, there is no way I am starting with this one. She works great, and as my first, it is also one of the most precious if not my overall favorite. As the radio that started this hobby for me, she deserves a true tune-up when I have some idea of what I am doing.

2. GE model 200 Bakelite - No hum, volume seems a bit low, especially at the lower end of the AM band - what causes that? The volume is half as high in the 600-800 range as it is up around 1000-1200. Otherwise works great, tuning is accurate and reception seems OK, although a bit weaker than all of the others.

3. Admiral 6T01-6A1-IV (also a bakelite radio) - Works great, no hum, accurate tuning, very good reception. The only knock on this radio is that you can barely see the thin tuning needle when the backlite is on, and the tuning knob is both tight, and sticks a bit.

4. Dunlop radio from 1936 - This radio is simply beautiful and has shortwave and the police band, the only one I have so far with shortwave. I bought it "restored", but within a couple weeks I heard a popping sound and since then I mainly tune in chirps and whistles on AM. Also, the tuning is sticky, and the tuning eye always seems to be fully lit up. Reception is quite weak even when it was restored. (This is another radio I don't want to start up with as it is the most valuable one I own and by far the best looking).

5. Arvin 35R48 tabletop radio - This one has a little bit of hum, although not really noticable and while it pulls in great on AM, it is basically deaf on FM. What causes a radio to be good on one band, but deaf on the other? Similar problem with the Sentinel radio I am going to list next.

6. Sentinel wood table top radio (model unknown, schematic and all other labels missing) - I just received this one today, plugged it in and it worked great on AM. No hum, great sound, good reception. FM was totally dead. I noticed that the lightbulb was not installed, so I went and bought one for it, plugged it back in and heard what sounded like a circuit breaker go off and that was all she wrote. None of the tubes are lighting now and the radio seems dead. This was the radio I bought to make as my first repair unit, now I am not sure as it is the only one I have that is not working at all.

7. Finally, the last one I want to restore - GE model 102 another bakelite radio. This one worked fine for about half an hour, after which time the audio became distorted and lower and sounds lousy now, in fact hard to make out the words. The dial light is also out of operation.

So, sorry to have typed out such a long post here. I am wondering which you would advise me to work on first, any particular books I should buy to help guide me along the way, and also any help you can give me in explaining some of the specific problems listed above would be greatly appreciated as it will help me to better understand how these radios work.

Many thanks in advance, oh, and I've got pics of all these radios and would love to share them sometime but am unsure about how to post them here.

PS - I thought I should mention my favorite radio as well. An unknown model number Silvertone dual speaker AM tabletop radio. I bought it fully restored, and it sounds wonderful (similar to the K731, although not as bassy, yet perhaps a little more clear). The reception is great, and it has the best looking dial I've seen yet with the red lettering and all. Sadly it arrived in pieces, but I wanted this one so bad that I glued it back together and kept it. I use this one on a daily basis to listen to Coast To Coast