The Fine Things are Always Hand Made
Good morning everyone,
This is my first time posting so please forgive me if I mess something up. I have recently purchased the radio stated in the subject line above and please see the attached pictures. Single tuner, Serial M-99, single speaker, and AVC with the Wunderlich tube. Before powering up the radio on a dim bulb tester, I notice the 80 rectifier tube was in one of the 45s' socket and the 45 was in the 80 socket. I decided I better start checking underneath the power supply before applying power. I noticed filter caps have been changed out in the past and some soldering on wires in different locations. I pulled the tubes out in the power supply and began tracing wiring and taking resistance measurements. The biggest GOTCHA so far is what I understand to be the audio interstage transformer. Please correct me if this is not the correct terminology. My Fluke meter shows an open circuit on all connections. I have never seen a transformer open like this. Anyway, I need a replacement. Performing research by looking at the grid and plate characteristics of the 45 and 56 tubes. I believe this transformer from Antique Electronic Supply could possibly work.
Any advice will be greatly appreciated letting me know if this part would work or I'm totally out in left field. I'm in and out of the house today so it may take time for me to respond.
Maybe not much help, but over 20 years ago, I found a person in either Tennessee, or Kentucky who rewound and re-coned a pair of Jensen A12s for me. The field coil for one A12 had shorted and burned the cones out of both speakers. I think a web search will be your best bet to find someone to do this. Another option would be for you to unwind the open coil and repair the break, since you have the coil out of the speaker.
Good afternoon Thom,
That was a lot of help. I value the opinions of Scott collectors. I performed a web search and there was a company who seemed to do a great job on antique speakers. They seemed to care about shipping and posted comments from satisfied customers. I will give it through the weekend for people to respond and after that I may email this company. I may as you say unwind to look for the break however; I'm so busy I do not know if I have time to perform this task. Thanks again for the great response.
When I had the A12s rebuilt, I built a wood box and bolted both speakers to a piece of 3/4 plywood locked into the box. The speakers were out of a Hammond tone cabinet. The woman I got the Hammond organ from had been a secretary in my office at the time. The organ had quit and the speaker cabinet had burned, which was why the organ quit playing. After the speakers were rebuilt, I put everything back together and the organ, which is from 1941, played like new. It still does, but now with a different set of speakers. I have also had 2 Jensen 15 inch and one Magnavox15 inch field coil speakers re-coned here in Chicago. These are out of Leslie speaker cabinets.
Good afternoon everyone! Interstage transformer installed (thank you Kent), and capacitors replaced in the power supply plus voice coil rewound by Nick at the speakershop.com. The voice coiled measured perfect plus it does look great. The speaker has already been reassembled and hopefully ready to go. Next question. Please see the picture with the line cord, switch and plugs. The black covered cloth wire going to the power switch is breaking down. The stranded wire looks to be 16 gauge wire. Do you agree on the gauge size? I need to be sure because I will have to order the correct gauge in order to successfully solder into the switch. I have vintage brown cloth covered power cord wire that I plan to use for the power cord. In the picture you will see the original plug sitting next to another plug. The plug without the wire I plan to use due to it's ornate design. Many moons ago I visited a lamp shop that had been around for many years. I raided there spare electrical plug box and purchased several plugs with these unique designs. I thought these type of plugs would look great on restored radios. Have a great day and I appreciate the responses.
The wire to the switch can be no. 18. I used regular plastic insulated for my allwave 23. If you haven't already, check out Sundial Wire for cloth covered wire. They also have the original style flat plugs. Restoring these is rather fun and the end result is very satisfying. Interesting when you can lose your tools in the chassis.
Thank you Thom for the reply! LOL on loosing the tools in the chassis. I have been checking out Sundial and will probably order the 18 gauge black. I had multi colors at 20 gauge but did not want to use that small a diameter on the primary side. Thanks again.
Good evening everyone. From what I can tell, the power supply and speaker are ready to go. Now it is time to work on the tuner. I had to step away for awhile due to overtime at work for hurricane Zeta but now back to business. The tuner is a mess. As far as the top end, broken grid caps on every IF tube plus clipped wires going to the grid caps. I will work on all this later and plan to start on the inside. To start off, I would like to verify the value of the bath tub capacitors. This is what I can tell by the markings on these cans.
Number on can Value on can Voltage rating Actual value
8047 1/10 uf 200V .10 uf
8048 1/2 uf 200v .5 uf
8049 1/2 uf 200v .5 uf
7204 1/10 uf 200v .10 uf
8050 1 uf 300v 1 uf
Please let me know if the capacitance values look correct.
I searched this forum and located great information about the bath tub caps on the rear of the chassis with a built in coil. I will follow the guidance of other restorations and leave these circuits alone unless there is a problem.
Lance - Those values look reasonable based on my experience. Remember, Scott sets do not always match the schematics exactly. If you find a circuit that doesn't seem to match, draw it out and compare. There are sometimes different schematics for the same model too, be sure to compare all of them. Good luck and keep asking questions!
Thank you for the prompt reply Kent. I would like to confirm the removal of the band selector wheel. Turn the selection knob fully counterclockwise or on broadcast and remove the two locking nuts. Do not turn the band knob until everything is reassembled. Does this sound correct?
Yes, that is the way. Do not lose the two springs and detent caps under the wheel. I always pull them out, clean them and set them aside until reassembly.
Thank you Kent. I appreciated the information.
Good evening everyone. I must be in transformer/inductor hell. This inductor (pictures attached) is open. Does anyone have one laying around I could purchase? This unit was connected to the interstage transformer which was opened as well. This radio must have suffered a hard blow by lightening or some type of power surge. Thank you.