[Kenneth F. Besso Jr.]

look like RCA knobs,,,,

[mikethedruid]

I have spent hours going over the circuit of this radio, and drawing, double checking, and redrawing the schematic for it. It is very, very similar to a Jackson-Bell model 4, the TRF version, but also different. Here are both schematics, first the Jackson-Bell model 4:

[Image: https://66.media.tumblr.com/2b33361c49c1...1_1280.jpg]

And here is the schematic for my mystery radio:


[Image: https://66.media.tumblr.com/e2ffa5e70f61...1_1280.jpg]
I know, I have had to edit this post a few times, each time because I found little problems with the schematic I had drawn. It is FINALLY correct. (I think)

[mikethedruid]

Things were going so well, then DISASTER ! I have the cabinet all done. The escutcheon polished up nicely, and then I shot it with some clear poly to keep it from tarnishing quickly. The new grill cloth looks very nice with it, since it is gold and black. I had reconnected the speaker, and tested the radio on my bench. It was working OK, so I started to put it back into the cabinet. Now I had decided to change the speaker mounting from 4 small wood screws put in through the back into the speaker board, to 4 flat head machine screws put in from the front of the speaker board, before I put on the cloth, with nuts on the inside, the the speaker, and 4 more nuts to hold it on. Well, the speaker didn't quite line up on the screws. Went to remove it, and the thick cardboard ring around the edge of the cone hung up on the threads, tore the cone to bits. Needless to say the air turned blue. I am sending the speaker to Nick Dorazio at The Speaker Shop in Savannah GA. Let him fit it up with a new cone.

[mikethedruid]

I called Nick Dorazio this morning and explained to him about my speaker problem. He told me he could rebuild it no problem, so I sent it off to him. In the meantime I have a 1 meg pot with a switch coming to replace the one in the radio which has some bad spots. I am not such an obsessive purist as to look for a perfect match for the original. I'm not doing a museum restoration. This is a brand new pot. The radio will look absolutely the same from the outside. It is like my philosophy when doing any radio repairs on these old sets. I don't try to hide the work I have done. I don't strip and re-stuff the old paper condensers, I just replace them with new ones. I figure this will make things a lot easier for anybody who has to service the set in future years. They will easily know what has been done, and what has not. Everything looks the same from the outside anyway. The only way you see the new parts is if you pull the chassis, and only a person who is going to do electronic repair work is going to do that. I figure, why make it more difficult for them. I know I wouldn't appreciate the cosmetic falsehoods were I going to work on a radio. It would mean I would end up replacing a lot of parts that I didn't need to, thinking they were old parts. Maybe it is a result of my doing these kind of repairs for over fifty years. It's how I feel, and how I do things anyway. So now I have to wait a few weeks to get the speaker back. In the meantime I have that potentiometer to replace, and I think I will make a brand new speaker board for the radio. I have enough grill cloth to cover it several times over, so I may as well do it so I can use screws the way it was originally done, and not risk messing up again. When the speaker comes back, if I'm happy with the result, I'll post the link to Nick's shop in Atlanta, so it can be added to the list of repair resources.

[OldRestorer]

Been there..
I poked a cone, burned a cone, dropped a cone, lost a cone,

Nick did my AK a few years ago. He does good work. I have never used but I have friends who used Sound Remedy in NJ but he doesnt rewind coils.

[Steve D]

I used Sound Remedy to rebuild an Arvin Rhythm Baby speaker that had no cone or voice coil and they used a new voice coil and did a great job. I don't know if they wound the coil themselves or purchased it though.

Steve D

[mikethedruid]

The field coil, transformer, and voice coil are OK on my speaker. Just trashed the cone itself. Nick said he would be making a new voice coil for it anyway, as he has found that using old ones sometimes does not last, so now he always makes a new voice coil. I'm glad to hear that someone else is familiar with his work. I look forward to getting the speaker back, and then finish the radio.

[Eliot Ness]

Sorry about the speaker Mike, but at least your little Pee Wee will sound its best.  My little 4 tube JB Peter Pan has a pretty bad cone so I'll probably send it off sometime also.

[mikethedruid]

I got back my speaker today, and hooked it up. It seems to be working fine, but I have some more issues to sort out. The volume control pot seems to be causing some problems. It seemed noisy before, so, while the speaker was being rebuilt, I took it out and took it apart and cleaned it. It does not seem to have improved things. The pot itself seems to be working fine, it reads smoothly as I wipe across the range. I'll eventually get it all figured out, I'm sure. The good news is, I can recommend Nick Dorazio , The Speaker Shop, as a good place to get speakers rebuilt. He is now down in Florida, no longer in Atlanta, and only does orders by mail. Here is a link to his web site. http://www.thespeakershop.com/

[mikethedruid]

I tried refurbishing the radio the way it was with no real luck, so I stripped out everything in the chassis, and am rebuilding it using the schematic of the Jackson Bell Model 4. which uses the same tubes, and from pictures I have seen of the chassis is almost the same as mine, except the layout is a mirror image, swapped left to right. I posted the schematic earlier in this thread. Hopefully this will get it going. I do hate the way they drew the tube diagrams in the schematic. I can figure out which grid is which from the circuit, but I wish they had used the standard way of drawing them.

[Jake Blake]

I agree on that tube drawing-thing. The only thing worse to me are the tubes drawn upside down   .  . . . . or at least what we, late-to-the-game think is upside down, ( Silvertone, etc.)  But the industry did , indeed, come to a standard on this later, and that standard is what I grew up with in the 60s and got used to.  I'm sure I'm not the only one.

[mikethedruid]

I finished with the re-wiring, except that I didn't have a 10K pot for the volume control, so I used the 25K pot that was used in the original circuit. Finally I am able to receive something! With just my body for an antenna, holding onto the antenna wire, I am able to pick up a couple of stations, which is an improvement over where I was. I still have a problem with "motorboating" sounds if the RF input is too strong. I'll chase that down. I have a 10K pot on order, I'll see how that affects things, but at least I'm getting there.

[Jake Blake]

Sounds like excellent progress.
I would like to know how you and others come to the conclusion that when you hear that motorboating, it involves the RF being too strong.  I think I hear that also, with this little Motorola, but assumed it needed an alignment.  What do you do about the RF being too strong?

[mikethedruid]

In my case I don't think it is the RF being too strong, I think it is that the circuit isn't handling it properly. The 10K pot may solve this because it affects the bias on the grids of the two type 57 tubes. We'll see.

[mikethedruid]

The 10K pot for the volume control arrived today. I undid the experimenting with bias that I had been doing for a while, and returned everything to the Jackson Bell Model 4 schematic. The radio actually works the best it has since I got it. The odd "motorboating is gone, and I am able to pick up a number of stations at night with my outdoor antenna. The volume is not very loud, but at least it now works.
[Image: https://66.media.tumblr.com/2c445a32e0e3...1_1280.jpg]