No, I didn't forget.
This year I picked the chassis of a Philco 41-KR, which uses the same chassis as those tiny five tube Transitone/Philco Transitone models.
Before picture:
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attachment=26033]
After picture:
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Before picture, underneath:
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attachment=26035]
After picture, underneath:
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I heard it play on Christmas Eve, so I'm happy.
I eliminated the filament dropping resistor and changed the tube layout so it runs on the regular AC line with no dropping resistor. This was accomplished as follows:
Change the 7A8 to a 14B8.
Change the 7B7 to a 14A7.
Change the 7C6 to a 14B6.
Change the 35Z3 to a 35Y4. The 35Y4 has a tapped heater designed for use with a pilot lamp.
Change the 35A5 to a 50A5.
The 14B8, 14A7 and 14B6 tubes have 12.6 volt filaments but are otherwise identical to the tubes they replaced. Likewise, the 50A5 is the 50 volt equivalent of the 35A5.
The radio isn't finished - here is what still needs to be done:
* Acquire a 35Y4 tube and install it in place of the temporary 35Z3.
* Wind a new loop antenna, or come up with a suitable substitute.
* Finish stripping the cabinet, perform needed repairs, and then paint the cabinet in white lacquer. This is a warm weather job, so it will have to wait until spring.
* Paint the replacement pointer white to match the original, broken pointer. Ditto.
You can read all the details on my blog in a few weeks.
Ron, you certainly are a glutton for punishment! Do I understand you that those tubes are exact pin-out replacements, or was rewiring involved here? When you are done, is there anything still broadcasting on that SW band? Forget the first question... I just took a closer look! Take care and BE HEALTHY! Gary
Want me to peek in my tube box for a 35Y4? Never know whats in there......
Lemme know.
Paul
Hello Ron
that is reminds me of the Deltrola chassis that our late ARF member Dale gave me .
Wow you love taking on the hard ones don't you ?
Sincerely Richard
The "after underneath" picture certainly is brighter
> Do I understand you that those tubes are exact pin-out replacements, or was rewiring involved here?
With the exception of the 35Y4, the tubes are pin for pin replacements. Only the heater voltages differ.
The 35Y4 uses pin 4 as a heater tap for the dial lamp; otherwise it, too, is a pin-for-pin replacement of the 35Z3. Philco originally used pin 4 on the 35Z3 socket as a tie point for other things, and that tie point must be removed. However, as my repair technique for these little Transitones involves stripping the chassis bare, removing all wiring and components and rewiring it from scratch, this is no issue.
Completely removing all rubber-covered wires and rewiring the radio is the only way to ensure the radio will be more or less "safe" now and in the future. Of course, no series string filament AC/DC radio is completely "safe," but they may be safely operated as long as common sense prevails.
> When you are done, is there anything still broadcasting on that SW band?
There is no SW band on this set, it is AM only. I don't know why Philco felt the need to include a second scale indicating meters. I feel it is redundant and a waste of time and space since we don't use meters to indicate AM station position in the USA. But hey - I didn't design the set.
I suppose since the pointer only sweeps 180 degrees on the dial, they wanted to put something on there to use what would otherwise be empty space.
> Wow you love taking on the hard ones don't you ?
I wouldn't say "love"...but I look upon them as a challenge.
These Transitones are so cramped under the chassis, plus being filled with crumbling rubber-covered wires, I have found that completely stripping and rewiring is the only way I can service them to my liking. Others may disagree. But I feel comfortable with my technique as it totally eliminates old rubber insulated wires and replaces them all with new wires.
And, really, it isn't that difficult to do, especially after you've done a few this way.
I don't feel badly about not restuffing paper capacitors in these sets. As you can see from the photos, the capacitors can use all the space they can get. The yellow film caps are great space savers in these radios.
Wow Ron, I’m going cross eyed looking at that cramped chassis! My neighbor found one of those tiny Philco Transitone radios in his attic, he said it was his grandfather’s and wanted to know if I would repair it for him. After looking at it I passed. Missing antenna, destroyed speaker and a crushed IF can
, no idea how that happens. Plus gobs of crumbling wire, I told him it was time to let it be. I noticed in your ‘after’ under chassis shot that the audio output transformer is missing. Good luck on your project, I know you will do your magic on it!
Ron
The audio transformer isn't missing - it is mounted on the speaker. It's smaller than the original audio output transformer, so I could place it above the chassis and the chassis will still fit inside the cabinet.
The speaker I used is a PM speaker taken from a 1955 Philco C579. The grille you see over the speaker was part of the speaker's original installation in the C579. It is on there temporarily until I can get the cabinet stripped, fixed, and repainted.
Totally nice job Ron!!
In answer to the "Meters" Scale, I have noticed the same thing on a 42 PT-94, my Emerson 330 and several pre-war RCAs. My 48-206 does not have the "Meters" Scale.
I think that the reason is that early on, Radio Station frequencies were expressed in meters instead of KHz Oops- Kilocycles. I have many TRFs and one working Superhet (a Radiola 60). even the "Single Dial" Units, (The Crosley 602 (DONT ASK), and the Radiola 15, 17 and 18, all have scales calibrated in a relative 0 - 100 Scale that corresponds with percent mesh of the tuning cap. One radio stands out, a 1927 Federal F 11 Orthosonic which has a dial calibrated- in Meters!! no corresponding calibration in Kcps.
I have done 2 Transitones, a 42PT94 and a 48-206. The PT94 was for a friend and was a total mess, requiring a complete rewiring. Was my friend's dad's radio and had a lot of sentimental value. I bought the 48-206 to donate the modern (polystyrene?) grille to replace the total mess Tenite grill on the PT94 but the radio was almost perfect cosmetic condition, complete with back, stickers, and original rubber power cord in very good condition. My friend is good at molding plastic so he created a mold and molded a replacement for his basket case Tenite Grille.
It is interesting how tube values change, likely based on availability, depending on year. The PT94 had a 50L6 as the only Octal tube, while the 48PT206 had a 50A6 Output and the Octal 35Z5.
May all have a Blessed Christmas and Holiday Season and may our New Year see God's Blessings for peace, harmony and an end to COVID
> Want me to peek in my tube box for a 35Y4? Never know whats in there......
Paul - Email sent.
Hello Ron,
For sure far as Room goes I have some small Arvin radios and the Detrola Pee Wee that I got from Dale .
Happy new year Ron and I will check out your link.
Sincerely Richard
Hello Ron,
man what a pain those IF cans I can feel for you .
Sincerely Richard