[Bob Andersen]

Here's another long neglected project that I'm finally finishing

It's a slant Philco 39-30 table top. It covers the BC and 5.0 - 18 MHz bands and features 8 presets.
The original finish is in pretty good condition but the decals around the controls are pretty bad. I picked up a set of repros and will attempt to carefully sand them off and apply the new ones. Then clear coat the whole set with some lacquer.

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The three electrolytics and one power resistor were replaced ages ago, but the rest looks original.
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I also picked up a set or repro push buttons and plastic dial face.
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The yellow caps are from when I started recapping this set a few years ago.
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First, I'm tackling the brittle power transformer insulation.
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I spliced in new wires that match the colors indicated on the schematic. Then, I sealed it with some hi grade wax.
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[Arran]

Bob;
I like the looks of these slanted panel Philco table sets but have never owned one, the closest thing I have is the chassis and speaker out of a 40-180, or the Canadian version of which. I did not know that the 39-25 through 39-35 sets had a celluloid dial scale, the chassis I have has one of the more typical back painted dial glasses in brown. Philco definately got some mileage out of that chasis, they used versions of it with as many as ten tubes up until 1942. I heard that some call them "console top" sets, maybe that was unusual in the U.S but in Canada it was a pretty popular idea, some even looked like they cut the top off a console with the speaker grille bellow and the control panel at the top.
Nice to see that the power transformer repair was successful. Do you know if the IF cans used rubber covered wire as well? By the way, I think that the other transformer/choke under the chassis is the output transformer, I'm not sure about the single ended models but the output transformers in sets with push pull screen grid inversion have a habit of going open.
Regards
Arran

[Bob Andersen]

The wiring is a real mixed bag. Some cloth, some flexible rubber wire and some rock hard rubber. Luckily only the transformer wire was actually falling off. I'm inclined to leave the rest alone.

Yes, that is the output transformer and it's good

I find the tube lineup a bit odd. 84, 6A8, 78, 37, 75 41.
I wouldn't expect a set from '39 to be using 75s & 78s

[Arran]

The wiring is a real mixed bag. Some cloth, some flexible rubber wire and some rock hard rubber. Luckily only the transformer wire was actually falling off. I'm inclined to leave the rest alone.

Yes, that is the output transformer and it's good

I find the tube lineup a bit odd. 84, 6A8, 78, 37, 75 41.
I wouldn't expect a set from '39 to be using 75s & 78s

I've seen a more bizarre tube combination the that, a friend in Alberta had a 1939 or 40 Philco bakelite that was not only an AC set but used 2.5 volt tubes like a 2A5 and a 58. Maybe they got a deal on the older types and thought they would build a set around them. Some of the later models with a similar chassis to yours used a combination of octals, loctals and old style tubes like 41s or 84s. I need to have a look at that chassis again, Ron was asking if they used more cloth wire in the 1939-42 Canadian Philcos and I think they did.
Regards
Arran

[Ron Ramirez]

Hey Arran,

I have one of the Canadian versions of Bob's set, a 39-330AT. It has the cabinet of a 39-25 and the six-tube chassis of a 39-30, but only has six pushbuttons.

The only rubber-covered wires in the 39-330AT were the IF transformer leads. All the rest of the wiring, including the power transformer leads, are cloth-covered.

My little Canadian 39-3A1 Bakelite table model is the same way - all cloth wiring except for the IF cans.

I recently acquired another Canadian Philco - a model 39 which is identical to a Philco Tropic 41-722. I have not yet looked at its chassis, but I suspect I will find cloth wiring in it as well. I hope so, anyway.

Bob, that is a neat table model and you will enjoy it when you have it finished. My 39-330AT has the same tube lineup as yours. Mine plays quite well on a good longwire.

[Bob Andersen]

Uh-oh. I checked the output transformer and the primary is measuring about 50,000 ohms instead of 400

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I wonder if something like a Hammond 125ASE would be a suitable replacement :

[Image: http://www.hammondmfg.com/jpeg/125ASE_B.jpg]

[Ron Ramirez]

The original matched a 6000 ohms impedance load to a 5 ohm voice coil.

That said, I think the suggested Hammond 125ASE would probably work as a replacement. You might have to experiment with different output tap combinations to obtain the best volume.

Good luck.

[codefox1]

The Hammond would work out fine, as would just a bout any single ended 9-12 K primary to voice coil transformer rated 3 or more watts.

[Bob Andersen]

Thanks for the advice. I have some good news. I performed a little surgery and restored continuity It measures about 430 ohms now. Hopefully it will hold up - 125ASEs are a little pricy.

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[Arran]

I've sen some more generic single ended output transformers listed on either the Radio Daze or the AES site that are less expensive then the Hammond ones, but I don't think that they are as universal with the different taps on the secondary. The type 41 has the same plate impedance as a 6K6 I believe so you could pull one from a junk chassis using that tube if the reapair doesn't work out.
Regards
Arran

[Bob Andersen]

I found a deviation from the schematic. Originally, The brown wire from the 1st IF coil was connected to the 2M resistor on the left. Now, it's going to the junction of a 2M and 0.05 cap not shown on the schematic. The other side of the 2M is pin #4 of the 78 IF tube.

Any thoughts ?

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[codefox1]

Well, I'd leave it as wired, (set played once or it would already be in landfill) but replace the remaining wax capacitors and if it were my set, I'd replace the associated resistors at the same time, as they will probably all read high. Then we'll see.

[Bob Andersen]

OK, I'll see how it plays as wired. Yes, I'll be restuffing all the caps and replacing out of spec resistors.

As I dug deeper into the set, I found more crumbly wire in the IF can so pulled it out. Good thing too as the mounting screw had broken away from the coil form which was flopping around loose. The resistor had drifted off spec too.

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Now I'm really glad I bought a multi-colored assortment of wire a while back
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[Ron Ramirez]

Bob

I just looked, and I do not find any production change mentioned such as you described.

Looking at the schematic, the brown wire of the 1st IF transformer was originally connected to a 2 meg. resistor (28), and a .05 uF capacitor (3). The other end of (28) connects to resistor (29), 1 meg., and to the plate of the 37 tube which is used as a dual-diode detector (the grid being used as the other "plate" with a 110 pF cap (19) between plate and grid). The other end of (29) goes to B-, and to the suppressor grid of the IF amplifier tube, a type 78.

[Bob Andersen]

Thanks Ron. The brown wire is long enough to reach that #28 resistor so it could be easily routed there. What I find really odd, is that the modification uses exactly the same type of resistor as the rest of the set. It's a twin for the one a few inches to the left. Also, the capacitor is a genuine Philco.