Project began March 11th, 2024, written on March 12th
So, I thought it would be fun to purchase an old floor model radio. I've always liked them and wanted one, and thought that it would be easier and cheaper to obtain one in Maine rather than Arizona. A quick look on Facebook Marketplace found a nice looking one that works for $65, much cheaper than what I usually see (never plug in an an antique radio you just got)! I did not know the manufacturer, model, or year until I brought it home, but thankfully there is a small but mighty antique radio community that has put together lots of information! Before I even took the radio out of the cabinet, I was able to identify it as a Philco Model 90L (L stands for Lowboy, the type of cabinet). It was introduced in June of 1931 and was manufactured through 1932 - one of Philco's earliest radios. It only receives AM radio signals. This point on, information gathering for this project quickly let me realize that this would involve much more time and energy than anticipated.
For context, my electronics experience doesn't go past building a PC and some basic soldering. This radio is entirely pre-WWII, consisting of seemingly loose wires, components, and vacuum tubes within and attached to a chassis inside this wooden cabinet. The nearest (and I believe one of only five in the country) professionals who work on these is all the way in New York, so definitely not getting any help there. Again, there is lots of info online from people who do this as a hobby so it has been, and will continue to be, a huge learning opportunity!
Cosmetically, the radio grille cloth (the fabric covering the speaker) is torn in multiple places and needs to be replaced. I was able to find a pretty close match at Marden's for $2.50 that I will be installing in the future. I do know there is a formal online shop for replica grille cloth, but at the moment I am content with this fix. Maybe one day I'll swap it. In addition, there is a small piece of wood accent that broke off and one of the legs is slightly loose. At this time I have no plans on repairing either.
Safety-wise, the original power cord was cut at some point and was spliced to a more modern rubber cord. It was done entirely with electrical tape... not very well. I re-spliced it and made it all nice with shrink tubing.
From there, I unbolted the radio unit from the cabinet, removed the knobs on the front, disconnected the speaker, and took the unit out. From there I removed the vacuum tubes (which I believe still work!), dusted the thing off the best I could (a quarter inch of dust/dirt in some places), and took a look at what was ahead for me. Inside/underneath the unit is the wonderful mess I get to work with:
To describe what you're seeing, the orange-brown cylinders are non-electrolytic paper & wax capacitors (condensers as they were called then), the red metal rods are resistors, and you likely cannot make out the additional capacitors and more from this photo. Capacitors and power cords are the two most common points of failure for old electronics. We've already replaced the power cord (at least part of it), and will be replacing all the capacitors. This is known as "recapping" and more info is on this website. This radio has definitely seen a professional repair person at least once, but definitely not recently - there are no modern parts in the radio.
As of writing (on March 12, 2024), the replacement capacitors are ordered and will likely arrive this week. Until then, I will be looking more into the radio's schematics (wiring diagrams are beyond me) and once they arrive I will immediately replace the wax & paper capacitors you see above since they can be done without a diagram. After that I plan on replacing the Bakelite container capacitors (which involves melting tar out of the container) and the electrolytic capacitors. Once that is done, I will power the thing on and hammer out any issues from there! Having received a functioning radio (with a hum and occasional "cut outs"), I hope the initial replacements will be adequate.
2nd Update: March 17th, 2024
Since the initial post I've spent about 7.5 hours working on the radio! I've learned a lot and have had lots of positive progress.
The first thing I did while I was waiting for my capacitors to arrive was replace the grille cloth. I am very happy with how it looks, although Butters was really trying to go to town scratching it. Thankfully now that my focus isn't on it her's isn't either (for now at least). I'll include a photo of the unit further down.
Once the capacitors arrived on Saturday, I immediately got to work replacing them all and noticed some unexpected quirks to this radio. Those Bakelite capacitors I mentioned before have already been replaced external to the containers they were originally in. For appearance and neatness this is not ideal, but functionally is not a problem. I did not have a hair dryer or heat gun yet so I replaced the capacitors without restoring the original look. Additionally, in this radio there originally were two electrolytic capacitors that are both in metal cans top-mounted to the chassis. You can see them in the diagram at the top of the page on the lower right corner of the image (they are not labeled). On my unit, one of them has been removed and replaced with a tube-style capacitor inside the radio.
It was my plan to keep both cans in place for visuals, but cutting their connections and replacing it functionally with a new tube-style capacitor. This means that my radio is missing one of the cans that visually would have kept it looking original. Again, not ideal but functionally totally fine! This did signal to me that the previous work done on the radio (im guessing 1950s or earlier, I couldn't find a date on the capacitors) was NOT done by a professional. Upon this realization I took some extra time checking wiring, and all looked to be a-ok! After one oopsie that was resolved, this is the result of the replaced capacitors:
There is so much more room in the radio since the new capacitors are so much smaller. Once this was completed, I could finally turn it on!
The test went great, there is only the slightest hum from the speaker meaning the capacitors are doing their job and there aren't any short-circuits. However, there is no reception being picked up. All the vacuum tubes lit up except for a Type-27, so I've put in an order for a replacement, which will hopefully be the final step to success! The pilot light for the tuning display now lights up, and below is an image of the front of the cabinet. I will provide another update after the replacement tube arrives!
3rd & Final Update: March 24th, 2024
The Type 27 Tube arrived yesterday and I picked it up today, popped it in, and voilà! Picking up stations loud and clear. Emphasis on loud - this speaker can make someone deaf without problem. The only thing is that it is quite out of tune. It can still pick up most of the band thankfully, but otherwise it seems that this project is essentially done until something else pops up. Tuning it is WAY out of my abilities, so I may ask around to see if there is anyone who could. Anyways, thanks for reading.
Brendan Trachsel © Copyright 2024 
