Work is now finished on the Loop Antenna that was in a state of disintegration. Many thinks to Jerry for his excellent work on making a new fiberboard copy of the original. The salvaged loop was then silicon cemented to the board and wires attached to screw-terminal lugs to facilitate easy attachment or removal via spade lugs. Sorry for the fuzzy image but I had to reduce the photo quality because of the 256K size limit.

wow didnt think that you would be going all out. I thought that everything bonds to nickle. base for chrome plating. should be great for soldering. this is what I found about chassis recovery
http://www.youtube.com/watch?v=-dbANTNv ... 1E5F6072B2
maybe noto what you had in mind but usefull info for those not doing a complete disassembly.

Although the chassis does have a couple minor rust areas, the main problem is that it's covered with millions of black dots. I've used Lime Away & Q-Tips and it takes the surface grime off but the dots remain. Notice the area where the IF cans were removed are clear but the surrounding areas around all the tube sockets is covered with black dots.

Raymond, have you tried naval jelly on the chassis? It tends to take those spots off which are probably rust. I suspect this picture was taken prior to removal of the sockets. You can go wild with the jelly with those sockets removed. Otherwise, if it gets into them, watch for the release of the hidden smoke. I know!
Jerry

Looks like things are going well. Just note the alignment of the replacement tube sockets so you can follow the original lead dressing and connections. (Don't ask me why I bring this up.)

If you removed the tube sockets, are you replacing the rivets with new rivets or screws?

I found that most screw heads seem to get in the way of the tube from fully seating... be careful.

Hi:
If you haven't figured out what to do with that broken case yet... here's an example of one that I got that could hardly have been worse... but we stripped it and patched what was needed and my friend painted it using auto paint.. here's the encouraging results showing before and after:

No, I have not used Naval Jelly yet but will try to find some today. If that doesn't work my only other idea is a bench grinder with rotary brush.

Good thinking and thanks for your suggestion. I had already anticipated that problem and put pencil lines on the tube layout chart indicating the keyway. I also have pictures of the chassis before I removed everything. I decided to take it all the way down because of the chassis pits & rust, brittle and cracked wiring, and the need to update the various capacitors & resistors. I'm also going to retrofit the speaker and the new one requires front mounting. That means I'll be drilling out the speaker mounting bracket. I've mapped the from-to locations of all the parts and wiring using Excel spreadsheets. Between that and collecting all the parts & supplies, it's a slow drawn out process.

I planned on using regular pan-head 6-32 screws but did not anticipated the potential problem you have pointed out. The chassis holes are only 1" diameter with mounting centers of 1 5/16" and are very difficult to find. But after a lot of searching, I found the item below on eBay. It's bottom mount so hoping with the mounting tabs below chassis, it will afford more room for the screw head. I won't really know until I try one. If they don't work, I'll have to use rivets as you suggest or look for top mount sockets.

Re: If you haven't figured out what to do with that broken case yet... here's an example of one that I got that could hardly have been worse... but we stripped it and patched what was needed and my friend painted it using auto paint.. here's the encouraging results showing before and after:

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Wow! You've done an outstanding job on the Radiola. I can only hope to get results like that. I'm wondering if the automotive paint was hand-held from a can or done in a paint shop booth?

As for patching, I went to a body shop and they suggested I buy the material shown in the photo below. I have not yet started any cabinet restoration.

POOF

Re: Sorry to write a book here, but you can use any or none of what I wrote.

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I will use as much of your information as I am able with my limited knowledge and I thank you. Radio Museum lists the cabinet as plastic "Modern plastics (no Bakelite or Catalin)". I will try holding the cracks open with tooth picks and then apply some super clue and see what happens. According to the seller, the 3M stuff I purchased can be sanded and painted. That, of course, is yet to be seen.

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I had great difficulty today removing the speaker bracket so I can prep the chassis and retrofit a new speaker. Rather than a couple rivets like the tube sockets, the bracket (only measuring 1.25 x 2.125) was spot welded in 5 places --one near each corner and one at the center. Funny they would put so much effort into attaching a small bracket and then use a lousy cardboard for the loop antenna and cabinet back. I had to hammer and chisel so much I was afraid the chassis would be destroyed. I would rather just leave the bracket on there but the modern 4" speakers intended for automotive use have a huge donut magnet that needs clearance.

Thanks,
It was not spray-cans.
...I'm sure my friend has an air brush or auto-paint type spray-gun as he otherwise does custom motorcycle gas tanks and such.
As for patching I really don't know what he used.. I just assumed it was something like "Bondo" or equivalent.

I'm now alternating between applying the naval jelly acid and going over it with steel wool and the black dots are slowly fading. The third coat if naval jelly is on there now and I've been leaving it on 20 minutes during each treatment. This crack house radio is not going to give up easily.

I still have several solder blobs to remove where they soldered pin 1 to the chassis. The new tube sockets I'm waiting for have ground lugs built into the mounting ring so I'm going to be using those. That sleight alteration is not going to make any difference in the 1 KHz frequency range. I've mapped all the parts & wires (as well as their lengths & dressing) so will be putting it back together as closely as possible as the original. However, I will probably have to do an alignment once the radio is built back up.

Maybe I can find a project to build a small crystal controlled 455 KHz oscillator one of these days as all I've got here in the former Ham Shack is a volt-ohm meter.

Finally I'm making some noteworthy progress! Below is the chassis after the 3rd application of naval jelly and going over it each time with steel wool. Just about all the black dots are gone; those that remain will be spot treated. Now I need to get my hot little hands on a grinding wheel so I can take the sharp edges off the spot welds. And like they say on TV, but wait there's more. The inside of the chassis needs the same treatment. Is there no end to this misery?

I'd go without a back before I'd pay $22.95 for one. He wanted $100.00 to make a back for a Philco 38-116. I don't know how he gets any business. JMO

Oh yes, I'm in full agreement here on that topic. For that kind of money, you might be able to buy a tool or materials to make your own.

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Now shifting focus to my RCA 66X1 for a moment, it had that annoying AC hum that I guess is "normal" with all AA5/AA6 radios having a half-wave rectifier. The parts list calls for a 50/30 dual wax unit and has the typical 1200 ohm 1W resistor between the two. I've converted the 35Z5 to a silicon diode (1N4007) in series with a 100 ohm 1W resistor and using a pair of radial-lead 60/40 uF electrolytics for filtering. But even with increasing each by 10 uF, I was still able to hear some AC hum with the volume control at minimum. Therefore, took another 60 uF radial and bridged it across the input capacitor rendering a total of 100 uF for input and 60 uF output. That took care of the hum problem and now it's hardly noticeable. So, we have a power supply consisting of AC line > 100 ohm > silicon diode > 100 uF > 1200 ohm > 60 uF > B+. (A doubling of what was originally used) Can anyone find fault with this wiring scheme? I know the 100 uF input cap is quite a bit but there seems to be no ill effects. What I'd really like to have is a 3-terminal voltage regulator that could be operated at 160V. Comments? Suggestions?

Should be OK. Now add a fuse. Your B+ still may be high, if too high increase that 100 ohm resistor to tame it.

I'd recommend not using an automotive speaker as they are not quite as efficient as the older speakers are. if the original speaker is ok then use it. If not check here for a speaker http://www.oldradioparts.com/pg2a32.htm

Concerning the RCA 66X1 I recommend removing your mods and installing a 35Z5. That should solve your hum problem.