Bakelite Crosley Multiband Restore
 

I paid too much for an old brown bakelite Crosley multi-band radio today at the trift, but man it was in great shape. All the knobs present, no cracks in the case, the back intact all tubes present, dial cover in good shape, tuner working... It has a large dial face, says "America" on top and "Overseas" on the bottom register.

I got it home and removed the chassis. I haven't plugged it in, and don't intend to without some good advice. I think the thrift guys might have plugged it in, so possibly the damage is done...

I have two questions. First, what is the recommended way to restore the finish on bakelite cases? My first thought was Armor All, but possibly wax? I've removed several years of cigar smoke.

ALso, I counted and including one large multi-value cap, there are about 10 caps that are candidates for replacing. Should I replace all the paper caps as a matter of course, or will that hurt the collector value? I guess I just need an education about restoring old radios as this is my first. I don't think its that valuable, but It's coool I'll post some pics later tonight.

Appreciate advice on where to go from here.

"Recapping", i.e. replacing all paper/wax and filter capacitors, is the first step in restoring a vintage or antique radio to past glory. If you want to test the radio before starting the recap, use a Variac (variable voltage autotransformer) or a dim bulb tester. Start out with the Variac set at zero, then bring the voltage up by degrees, observing the chassis at the same time. Stop immediately and unplug the power if you notice smoke and/or sparks coming from the chassis; this indicates a short circuit which must be corrected before going further.

The dim-bulb tester may be used if you don't have a Variac. Connect a standard 100-watt light bulb in series with the radio's line cord, then plug it in. If the bulb lights normally, you can safely go ahead with further testing. However, if the bulb lights to full brilliance and then burns out with a bright white flash as soon as the radio is turned on (or, worse, as soon as the set is plugged in), there is a dangerous short somewhere in the chassis which must be cleared before anything else is done to the radio. Shorted filter capacitors and/or a shorted rectifier tube will cause excessive current drain, which will blow the house fuses or the line fuse in the radio because the caps and rectifier tube are in a position to short the power line directly to ground if defective.

Thanks for the advice Jeff. I'll go through and make a list of all the caps, then out to PE to order. The model is 66-TA. Any advice for restoring the shine on the bakelite finish?

Just wanted to add some comments on the dim bulb tester (which is basically a plug with a lightbulb in series - check out this link: http://www.antiqueradio.org/dimbulb.htm).

The dim bulb tester is a good way to go and any newly acquired old radio or newly worked on old radio should only be switched on while using one. For a normally operating 5 tube radio a 60 watt bulb should glow dim while the radio is on. If it glows brightly right away there is a short circuit in your radio somewhere. The link describes some other tests you can perform with the dim bulb tester.

The general consensus these days seems to be that recapping will not hurt the collector value, but some people go to such lengths as matching wire colors, refilling aluminum cap holders, and even hollowing out the original paper/wax caps and putting the new ones inside the old hollowed out one. I haven't yet, but on a very special or valuable radio I would perhaps consider taking the trouble. It may not be a problem with collectors in 2009 but who knows if it will matter 100 years from now.

Here's a link for some advice on restoring bakelite finishes:

http://web.ukonline.co.uk/freshwater/bakelit1.htm

Armour-All is mentioned on it.

StarMover...... c'mon, you know the drill ! Where are our pix ???

Just looked up the model and although it sure looks like bakelite in some of the photos, the info I'm finding is that the 66TA is not a bakelite radio, but is made of plastic. You may wish to explore this further because plastic is much more delicate concerning solvents and such than is bakelite so the advice for restoring it will be quite different.

Pics of the Crosley
 

Ok, here are some pics. As you can see I've removed and dusted the chassis. The bakelite cabinet was nasty with smoke residue. I'm surprised the plastic dial cover is in perfect condition. Not sure about tubes or other components, I'm just going to assume a recap. Neat field coil speaker. Does that date this radio? I'm guessing around 1940?

One more pic of just the cabinet.

I just assumed bakelite because it looked like it to me... Plastic would make it a little later model, perhaps late 1440s early 50s.?:scratch2:

Yes. I'm seeing dates of 1945-46.

http://www.crosleyradios.com/66ta.html

http://www.radiomuseum.org/r/crosley_66ta.html

http://radioattic.com/item.htm?radio=0094009

The last link there describes it as bakelite, but if you try a google search for Crosley 66TA Plastic you'll get a lot of links that claim it is plastic rather than bakelite.

There are some tests you can perform to check for bakelite. The smell test is as follows: Rub the item in question vigorously with your thumb until you feel the plastic heat up. Then, before it cools, take a whiff. A distinct chemical odor similar to formaldehyde will linger with most genuine Bakelite. This often takes a bit of practice. Some noses find better results when the piece of plastic is placed under hot running tap water before sniffing it. There are other ways to tell from the weight, or the patina or even the type of wear. You can find lots of suggestions for testing on the internet.

After looking up the Crosley I now am beginning to suspect that a Northern Electric I picked up last week and assumed was bakelite may be plastic as well. http://www.audiokarma.org/forums/att...2&d=1241282754

BTW. Nice looking radio and in great looking condition as well. I can see why you bought it.

The seller cited in the radioattic link contacted me and confirmed that his is indeed a plastic composite of some kind and not Bakelite.

THanks for the follow up!

I took inventory of the caps today. There are 7 flat caps, the rectangular jobs with the six colored dots. How do I derermine the values of these? Should I just replace them with normal caps as the other ones?

The "flat" caps are mica caps...normally shouldn't need replacing. (Although they HAVE been known to go open once in a while). There remains a possibility of a drift in value with age...but it's a pretty safe bet you'll be OK. Sweet looker there!!

Thanks ej, I wasn't looking forward to replacing those.

I've made a list of cap values I'll need for the project, but after looking at a couple of online sources, I've become confused about exactly what kind of caps to order. There are WWII, post-WWII, Tubular, etc. The caps required are:

.005 MFD 600VDC (x3)
.01 MFD 200VDC (x1)
.01 MFD 400VDC (x2)
.05 MFD 200VDC (x1)
.05 MFD 400VDC (x1)
20 MFD 275VDC (x1) (large)

There is one component, that I think is a cap, but it looks like a large resistor coded (orange, orange, brown, silver) stripes. I've circled it in red on the attached image. Is that a cap, and if so, then what is the value and what do I replace it with?

If someone could set me straight, I'd appreciate it! :yes: I'd hate to order the wrong parts. Thanks, PJ

That's a 330 ohm resistor, and looks to be fairly hefty...at least a 2 watt if not larger. If you don't have a color code chart...bookmark this: http://www.ealnet.com/m-eal/resistor/resistor.htm Very handy.

still waiting on my parts. I didn't realize that SimplyRadios was in Canada! I've started replacing some of the brittle rubber wire, but I don't want to get too far along without my new caps.

Don't worry, the border is still open for business! Good luck!

Got parts today. Amazing how much smaller modern caps are... 3-day weekend coming up, so perhaps a chance to put a couple hours in.

Great Sound!
 

What a Fantastic find at the thrift store! The 66 series is a stunning looker and performer. I have had several over the years and kept the best one of each model (Brown, white, wood and wood victory so far). Well done!-Ray>:thmbsp:

I finished replacing all the wax caps and brittle wire. I need help replacing the electrolytic cap 20mfd (the large one on the left). Not sure how to wire it up. The old cap has 5 wires coming out of it. Assume one side to chassis ground, everything else to the other end?

http://www.audiokarma.org/forums/att...0&d=1241754743

Forgive me if I explain something that you might already know.

You need four 20uF electrolytic capacitors to replace this multi-section electrolytic. Each of their negative leads will go to chassis ground. This is only true because your set uses a power transformer. Hot chassis sets would have a seperate ground.

The positive end of each electrolytic would go to where each of the other four leads of the current capacitor connects.

John

Thanks John! I'm still getting my head around this electronics sutff. My first thought was that this was a multi-value cap, then I saw marked on the side only one of the values was highlighted with a black dot, so I ordered only one (and a spare in case I screwed up). All the values were 20uf, just different voltages. Can all the new 20uf electrolytics have the same voltage rating (450) or should I match the values of hte old cap?

As long as the voltage ratings of the new caps are the same as, or higher than, the old caps you'll be fine.

John

I'm REALLY interested in how well this l'il guy performs after you get him all squared away...I'm bettin' you'll be pleasantly surprised !

I'm just hoping I don't screw something up. I'm trying to be real carefull. I've replaced all the caps now, only need to acquire to more of the 20uf electrolytic caps. I broke a resistor, so I've also got to score a replacement for that. I hope rat shack has these parts, there is no longer an 'old school' electronics shop here. Most internet sellers have a minimum order $$.

New Pics
 

Here is the Crosley Model 66-TA radio mocked up on the bench. It looks pretty nice. The case was cleaned with polishing compound and waxed. The clear plastic dial cover is cleaned and reinstalled. The unit had been splattered with paint. what a PITA to clean all those thousands of white dots off!

Under the hood I still have to replace two more electrolytic caps plus the resistor I broke. I'll go hunting parts locally next week. I can't wait to see if it works.

Question: Would the original power cord have been cloth-covered? I don't think this cord is original. It has a 60s vintage plug. :scratch2:

Edit: I found an identical 66 in a wood case on the auction site. See pic attached.

I doubt that the cord was cloth covered, but perhaps someone knows for sure. There are some very nice reproductions out there if you decide to go with cloth.

My 1948 Arvin had a rubber cord and this link has replacements that are very nearly identical to what the Arvin used. http://www.radioantiques.com/supplies.html#cords

John

Well, I finished with the recap. When tested the 5Y3GT began sparkling then got hot. At least a bad tube, possibly a short somewhere. I ordered a trio of tubes for $10 on ebay, so we'll see. Next time I'll bring it up on a dim bulb as the wise folks here suggested. Should have done that in the first place, but too anxious to take the time. Lesson learned.

Any progress?
John

I collect and restore old radios for my main hobby and you will find that when you get this radio running right it's a very good performer. Most old radios you find only need a the caps and electrolytics and an alignment. A good place to go for schematics and other info on old radios is Nostalgia Air here's the link
http://www.nostalgiaair.org/. Good luck with your radio.

I'm gonna have to get the schematic because something isn't right. The dim bulb test worked, but when I plugged in to 110, a resistor got hot and started smoking. I think the 6V6 is fried as well. This project is getting over my head. It needs more than I have skills.

I can't imagine how your radio passed the dim-bulb test if a resistor started smoking when you plugged the set directly into the line. There is still a major problem with the power supply, especially if the 5Y3 rectifier tube is running hotter than normal (as you mentioned in a previous post; you also mentioned the tube was "sparkling", which means trouble as well). The resistor you mention is burning for exactly that reason--the component is being called on to handle more current than that for which it is rated. Did you replace the filter cap when you recapped the chassis? If so, that rules out a shorted filter and leaves either a shorted high-power tube (such as the 6V6 you mentioned) or, worst case, the power transformer. When a resistor burns and smokes in any piece of electronic gear, you can be sure there is a serious short somewhere that must be corrected before the equipment is used again.

The 5Y3 rectifier running hotter than normal is a danger sign as well, as I mentioned above. There is one other possibility--I don't know whether or if this would apply to a transformer-powered radio, but I'll put it in here anyway. Does the dial light work when the radio is switched on? If not, I'd replace it ASAP. I mention this because in some radios, the pilot light is part of the power supply; for example, I have a 1951 Zenith H-511 that uses a pilot lamp as a current limiter. The lamp glows very dimly when the radio is switched on from a cold start, then brightens as the set warms up. When the tubes are fully warmed up and the set starts to play, the pilot light is at its maximum brightness. If there is a short anywhere in the power supply (or if the 3-section electrolytic filter cap is deformed from years or decades of disuse), the pilot light will burn out with a bright flash. If the radio is used without the pilot lamp in the circuit (e.g. the bulb is burned out), the 35W4 rectifier tube will glow brighter and run hotter than normal, leading to premature failure of the tube.

Note that the foregoing applies to series-string radios with pilot lamps; as I said earlier, I don't know if the same applies to transformer-powered sets. Again, that the 5Y3 rectifier tube in yours is "sparkling" and also running hotter than normal, not to mention the burning resistor (which is probably a large power resistor in the supply circuit, near the transformer), are unmistakable indications of a very serious short in the power supply.

I will gladly box this radio up and ship it to anyone who is willing to try and save it. I'd rather give it away than ruin it. It is too big of a project given my electronics skills. PM me...

The pilot light does not affect the B+ in a transformer set. Check your electrolytic capacitors. If you installed any of them backwards, this could be the problem. There is a strip on the side of the caps with minus signs on it pointing to one end. The wire from this end will come out of the outer aluminum can of the cap. The positive wire from the other end emerges from an insulating disk. If you find one backwards, replace it with a new one because it will be damaged. By the way, the voltage rating of these caps ought to be the same or slightly above the voltage rating of the original caps. This means that such caps used in the cathode circuits of tubes ought to have lower voltage ratings than the filter caps used in the B+ circuit.

Check all your B+ wiring. There could be a short somewhere causing B+ voltage to be shorted to ground.

Did the transformer pass its test before you even started on this radio? Try this: pull all the tubes. Plug the radio in to the dim bulb tester and turn on, using about a 60 watt bulb. Bulb should not light, or only very dimly. If it lights bright, your transformer primary is bad.

If you got a dim bulb on that test, a good sign, now put all the tubes back in EXCEPT for the rectifier. Plug the set into the wall and see if tubes light. If all is OK watch carefully for a few minutes, feel the transformer, listen, sniff.

If all looks OK, leave the rectifier tube out still. Turn the set over and check the AC voltage between the two plate terminals on the rectifier. Should be several hundred volts. Now check between each plate and transformer secondary center tap. Each should be approximately half of the previous figure.

If all these tests are OK, your transformer is OK and you have a short somewhere in the B+ wiring, or an electrolytic reversed. Don't try the radio again with the rectifier tube until all B+ wiring has been checked.

Download and print out the schematic and then using a highlighter, trace every circuit in the radio, highlighting it when you are sure of it. This takes time and concentration so don't do it when you're tired. Spread it out over several sessions if necessary. It's a good exercise and you'll see how the actual wiring is done versus the drawing. This should lead you to find the problem.

BTW, the cord and plug on that set would have been moulded rubber. Cloth cords went out depending on the manufacturer around 1936-37.

Reece

Did you test the radio at any stage while recapping? When a radio works (even if poorly), I briefly try it out after replacing every cap or two, to make sure I didn't space out and miswire something. I also check off each cap on the schematic and parts list as I go.

If the radio worked OK before you replaced the last two electrolytics, they are obvious culprits. It's easy to connect one backwards. Also, when you have more than one component disconnected at a time, it's easy to forget where the chinbone connected to the neckbone.

If you didn't test the radio or keep notes, I would carefully doublecheck the wiring of every capacitor that you replaced, using the schematic as your guide. Is it the right value? Are both ends connected to the places where the schematic says they should go? Note that schematics sometimes show parts located close together which are far away in the physical radio, and vice versa. Using an ohmmeter to check connections may help sort things out.

Finally, is it possible that you mixed up the tubes and accidentally swapped two of them when putting them back in the sockets? Sounds obscure, but many people have done that in a moment of inattention with tubes scattered around the workbench.

I would not give up and send it to someone else at this stage. A printout of the schematic and an ohmmeter can help you confirm that all of your capacitor replacements are correct.

This article has general advice about recapping: http://antiqueradio.org/recap.htm .

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html