This seems like a pretty unique (or at least very interesting) radio, so I thought I'd make a thread about it. I got it over winter break from craigslist for $90, and I think I got a pretty good deal. An RCA Loudspeaker 106 (1927, I believe) also came with it. What I think is very cool is that the radio seems completely original and the seller was the original owner's grandson. When I got the radio, it was extremely dirty with everything from dirt to leaves to mouse poop on the inside, all these pictures are after about an hour of cleaning! It also came with some original documentation as well as a letter from the "Sparks Withington Company" explaining how to hook up an external speaker (probably the one that I got with it). The seller said that it did not seem to work and that he "heard the problem might be a fuse"... Both fuses are fine, and obviously I haven't tried to plug it in yet - so I'm really hoping nothing got messed up when he tried turning it on. One of the doors is broken off at the top hinge, but I have all the pieces so I should be able to put it back together pretty easily. Also I have no idea what to do with the finish - it literally flakes off whenever I touch it. If possible I'd just refinish the moldings that are peeling but the top doesn't look good either... Any opinions on this are welcome (I'm not sure if it's a laquer or shellack finish, I heard shellack was used to finish the very early radios). Sadly I probably won't get to this for a while as it's sitting at home while I'm at college - but in the worst case it'll get done in 3 years Since this is so original, I'm planning to re-stuff the few capacitors that need to be replaced (I think there are less than 10 total), including that HUGE filter can on the power converter chassis (which is apparently several paper caps instead of electrolytics). This won't be my first radio, I've fixed a few small ones already successfully so hopefully this won't be too different. Thanks to some other members on here I was able to get the orginal schematic with values of all components so if anyone needs it I'll gladly send it to you. Enjoy the pictures and any comments / suggestions are welcome

And here is the Equasonne website which has been pretty helpful, even though they list this as a model 110 for some reason:

http://spartonequasonne.webs.com/

More pics...

That looks to be in good shape a very nice radio.

Very nice indeed! You have the 50s and 81s intact!

One bit of advice, make sure someone didn't replace the six 484/485 tubes in the RF amp box with 27s. While one 27 won't be a problem, having all 6 will tax the power transformer as their heaters draw significantly more current.

The 484/485 is rated at 3 volts 1.25 Amp.
The 27 is 2.5 volts 1.75 amp

In a pinch, a better choice is the 56 as it is rated 2.5 volts at 1 amp.

The Sparton Equasonne is a unique radio as it uses the Technidyne circuit. It does all the tuning first in a 4 stage tuner, then sends the tuned RF into a broadband amplifier. It works surprisingly well, though you will need a fairly good antenna on it.

Good luck with your Sparton!
The finish on these is nitrocellulous lacquer, although I suppose shellac would be a fair substitute.

I'm no expert in reinishing...


-Steve

I have that same cabinet I bought from a forum member with a later other-brand radios retrofitted into it.
Mine has a hinged top lid interestingly. I don't know if that was an option or done later by a craftsman.
These are fine high quality cabinets. I hope you get your set going again.

I wonder what size the original speaker was, as the grill opening is quite large on these.

Awesome score!! Great radio and a 106 to boot!! Wow. Mike...

Here are some pics of the speaker. It's also all original but I haven't tried it as the wiring needs to be replaced badly. I will also keep this as original as possible with period-correct wiring. Maybe the coolest thing about this is that it has a big yellow repair tag hanging on the inside dated 1929. Apparently that's when the speaker cone was replaced (as the tag says).

Very nice! Be EXTREMELY careful with those 250s, as replacements will be staggeringly expensive. When restored, that set should knock your socks off.

Ditto !! I would have those two tubes up on a high shelf someplace. Run the radio on a pair of triode wired 6L6 tubes. That pair of tubes is worth something around 400 bucks or so.

John k9uwa

Wow, I read somewhere that those tubes were rare, but I didn't think they were this rare. Just to look, I looked on ebay and there is a pair for auction that is currently at some $360 with about 2 hours left on the auction... wow.

When I get around to restoring this radio I will definitely use different tubes if possible and keep these somewhere safe. Does anyone know of any fairly cheap and common tubes that would work as a direct replacement for the 250s? Also, are the two 281 tubes rare and expensive as well? They are the exact same size and shape (I think these large globe tubes look super cool), but obviously I know that the appearance doesn't dictate value...

The UX-250 is not even close to being rare, just popular for audio use which drives the price up.
What good are the tubes if you don't use them? 250's last forever and they are probably safer in the radio than stuffed in the closet somewhere.
If you have to sell them or hoard them, the best thing to put in the radio is a set of "weak" 250's which the audiphools won't touch, but work fine in radios with usually no noticeable drop in performance.

281's are $10-$20 tubes.

True, the 281 is pretty much a 250 without a grid, but it isn't anywhere near the value.

There is no direct replacement, but John has an interesting idea of wiring a pair of 6L6Gs as triodes. You would need to make two adapters with old 4 pin tube bases. Preferably with the side pin.

I believe the screen grid is tied to the plate? correct me if I'm wrong.

Granted, I've been using my 50s in my radios. call me nuts?

Bruce: I know the 109 has a huge grill, but it uses the same 9 inch Magnavox most Spartons of that vintage use.
Maybe the cabinet was designed while sparton was using an earlier magnetic speaker? Those are at least 15" in diameter.

-Steve

Completed Auction for a sort of matched pair.

http://www.ebay.com/itm/Two-Cunningham-CX-350-50-globe-balloon-matching-pair-UX250-UX-250-equiv-/220974185261?pt=Vintage_Electronics_R2&hash=item3373167b2d

Your Nickel if you want to run them in your radio.

6L6 in place of 50 tubes. Yes screen grid tied to plate and cathode tied to one side of the filament. Adapter is a junker 4 pin tube base and an octal socket. If you use glass 6L6 tubes best to also put a 0.7 ohm 3 watt resistor in series with your filament as the 6L6 is a 6.3 volt filament and the 50 tubes are 7.5 volts. Or if you don't mind looking at metal tubes just use metal 1614 tubes. They will take the 7.5 volts and not complain.

One more tidbit on this chassis rebuild. First Litic needs to be well over 500 volts. This thing will blow a 450 volter on turnon as the B+ comes out of the 81 tubes long before the 50's or 6L6 tubes start drawing current. Easy is to series a pair of 10 Mfd 450 volt litics giving you 5 Mfd at 900 volts.

Wouldn't hurt to also use a bucking transformer and drop the juice to the whole power transformer. It is 70+ years old.

John k9uwa

You know, for as much as 50s are going for, why havn't the Russian/eastern bloc or Chinese started reproducing them? I see you can buy Chinese 2A3s now.

I've been using non electrolytic caps in my Spartons. I know they are expensive, but you can get 4.7 uf @ 600V axial capacitors from Mouser and Newark.

That, and I've been building up caps from a big bag of 4.7 uf @ 250V I ran across.

-Steve

They are: http://www.ebay.com/itm/Shuguang-type-5 ... 0359390544

Thumbs up on using film caps. I've been using them more and more for replacing filter caps in the 2 - 10 uF range.

The very best place for those tubes is in the radio, and that's also the safest place. They'll last forever, for the short time you'll actually be demonstrating it.

As noted, the finish is nitrocellulose lacquer. Some careful touchup with Mohawk toning lacquer (applied with a brush) would make that cabinet look like new.

That's way above average condition for the RCA 106.

Well this thing is still sitting in my mom's storage unit, so I probably won't get to it anytime soon but I was just wondering if Sparton ever made record players to go with these radios? Since it has a "phono input" jack and I know some of the other models of that year had a built in record player there must have been some kind of electric phono that could have been plugged into a radio like this... anyone know if Sparton made one or what a period correct electric record player would look like? If I could find one that would be small enough to sit on top of the cabinet I might eventually want to get one. Any thoughts?

Congratulations, both are excellent finds. I've got two spartons - a Model 301A, and a Model 79A.

this is one of my favorite Spartons sets i had one about 15 years ago and regret selling it,saw one on CL that was very modified
didn't buy it ....

with regard to 50's i have bought 10 for my set in the past 2-3 years ,and never paid more the $100 apiece Don

I once had a Sparton 109 chassis that was given me by the original owner, who kept the cabinet and gave me the chassis. this was in 1945 or so, and I was still learning about these sets. I had a little RCA 78 RPM player attachment that I used on lots of sets, to include the 109. The gain wasn't impressive, but I learned about the extra audio stage that was on some Sparton models. I made one up for the 109, using a 27, on the tuner panel board. it provided the additional gain I needed, and as someone said earlier, could blow your socks off. LOL, that was the best sounding set I had up to that time.

On the issue of the 50 tubes, I have a total of 21 or 22 50's in sets in my collection, and I have spares. I stocked up on them long ago, when I smelled this situation coming. No problems here.