[Radioroslyn]

Proceed! Check the DC volt at the cathode of the 84 that's the important thing.

Terry

[MarkBardenwerper]

Thanks.
I think things around 84 are not what they aught to be. I got as far as getting some good readings from the audio transformer. But there are three new caps in that area, two grounded at the backlite case (must be #65 in the schematic) and between one end of the candohm and a leg of 84.
I also see some other intruders on the rear 41.

Waddya think?

I am tempted to remove them and try to get this circuitry back to the way it belongs. I'll wager they are part of the power transformer graft. You can also see how the replacement transformer is cobbled in.

You can also see where that some original caps that were clamped to the front wall of the chassis are gone.

[Radioroslyn]

Looks like those are just replacements for the originals. However probably  done 40 or 50 yrs ago. I'd replace them too. Yes the original transformer did take a dump. that's what all that brown is from on the chassis.

Terry

[MarkBardenwerper]

Hello folks,
I think the number of issues with this chassis make it a good candidate for a graft. I found a 41-285 on Ebay and I wonder how good a choice this would be for either swapping or using as a donor. The transformers physically look the same and the resistances are alike. Getting just that might be worth it, along with tubes, extra coils, ext and this one might have been partially restored already.

Are there any differences that might make me think otherwise?

http://www.ebay.com/itm/281752672003?_tr...EBIDX%3AIT

[jerryhawthorne]

Mark, it looks like the 41-285 has has substantial recaping done on it and the work looks good and recent. Others can advise as to how it would "fit" into your cabinet. The chassis does appear to have a line switch added to no doubt bypass the on/off switch on the chassis as these were very prone to failure. There are threads showing how to sub in available new switches or perhaps the one on your chassis is still good.
Good luck, Jerry

[MarkBardenwerper]

I think the chassis are essentially the same except for the addition of another tube. Pretty sure they are the same dimensions. In effect it is a minor upgrade.
Here is the electronic side
http://www.tuberadioland.com/philco41-255T_main.html
(I'll wager the 485 is a 455 on stilts. Same speaker trans part no.).
Some sites say the sound is much better, others say, not much.
Additionally, the faceplate has a minor difference. Mine has a an additional box below the band indicators that says, "push but." Instead of the cable operated single indicator light, the 485 has a switched row of lights (missing here).
But the output section looks to be the same. It might be an interesting swap, but I think I would just use it for parts. Here are top and bottom views of the 485.

[MarkBardenwerper]

Today, the 41-285 chassis arrived and I am impressed with its overall condition. It was reasonably priced at $28 plus shippiing. The only changes done to it are several new caps, not the neatest job, but easily improved. The tubes are all there, so now I have spares. Still could not test the 41's or the 85. No biggie. The power switch might be donnage, as it has one on the cord. It feels as if it works.

Solid wiring and no rust are it's biggest plusses. Original trans looks very good. Will test it yet tonight.
Did some research and so far, I see no difference between a 285 and a 255 chassis. They both have the additional 7A6 tube and the diagrams are clones. Will learn more as I proceed. 250, of course is the little sister to 255 table top, with this tube absent. 285 is a floor model crate.

Push buttons are in excellent condition. It has an additional light behind them. I wonder if they went to the wine colored buttons the next year to take advantage of that. The two faceplate lights are separated by a long slender plate. Seems a lot of bother for no reason, but this one will probably show brighter. I am not going to bodge it with the wrong (wine) buttons. I now have two sets to choose from, an old and a new.

Notice in the top picture the difference in the indicator on the 250, which has a single swinging cable operated indicator light. The 285 has three fixed lights (one wire present, all lamps absent). I do not think this is a model based difference. It is date based. According to the product changes at the bottom of the specifications and parts page, one of the later modifications was to get rid of the multiple lamps and go to this "swinging single" arrangement. One giveaway to this is the 285 is not drilled to accept the guides for the cable which is to the far right. The setup on the 250 is in good nick, but I do not see myself retrofitting the later gizmo on by installing the guide and fitting the tuning scale upright (which has the light swivel riveted to it) from the 250.

Also notice the difference in the faceplates. The one from the 285 is in better condition. Despite the presence of the square that says "Push But" on the one from the 250, the light does not swing that low so it is really senseless. Tuning scales are identical, but the mapping is changed, probably reflecting changes in the band usage.

A few tests should tell me conclusively which chassis to use. I am pretty sure right now it's the 285. This radio is common enough that I don't feel obliged to keep it original.

[Raleigh]

The early production runs of this series of radios had the type of dial lights as are in your 41-285 chassis. There was a dial light for each the 3 bands that illuminated the names of the bands on the right side of the dial. I think there was a fourth bulb behind the push button station labels that would shine through the labels when you were in push button mode. There were (I think) 5 bulbs in all, counting the central bulb for the whole dial.

In later runs Philco eliminated the 3 bulbs on the right side of the dial and the station label bulb, and substituted a single bulb in a swiveling holder that moved up and down to illuminate the name of the selected band. That way they saved the cost of 3 bulbs and holders and a more complicated band switch in exchange for the presumably lesser cost of the mechanical swiveling assembly. The dial changed to include the words "Push But", which were illuminated by the swivel bulb when you were in that mode.

I just ordered the service information from Chuck Schwark for a 41-255 I'm working on. There is a note in tiny print describing the production change beginning with run 5 for the 41-255. Maybe different run numbers for different models.

My 41-280 has the early system, but my 41-250 and two 41-255s have the later type.

If you haven't already, you might want to order the service information from Chuck Schwark. It is very complete with a blow-up of the schematic and usually the under-chassis diagram to 11 X 17, so everything is clearer and easier to read. You can order from his web site. You send a check and get the clear copies in the mail. http://www.philcorepairbench.com/schematics.htm

By the way, the wine-colored buttons were from the 1940 model year (and maybe '39, too). I have a 40-150 and a 40-190. Neither of those has the extra bulb behind the push buttons. They suffer from uneven illumination by the single bulb, but they still look good. I imagine some clever person could rig up an LED strip to get even illumination through the red bulbs.

P.S. It might be a good idea to make a clear a diagram of the run of the dial cord that operates the swivel mount. If it ever breaks, it's easier to fix if you've diagrammed it carefully beforehand. The Philco schematic was drawn up for the earlier multi-bulb system, and the dial string diagram doesn't show how to string the swivel mounted bulb.

[MarkBardenwerper]

I have a set here for the 250. Valuable far beyond the cost! I am confindent enough in the 255 diagram that I should not need one for a 285. The rest of the paperwork indicates this as well.

No, there is no diagram for the swivel light. I redid it a long time ago and it is in good nick. The routing is simple, but it was a trick to get the tensioner spring in just the right spot to keep it from tangling in the guide. I started cleaning the 285 and pulled the light wires back slightly that go down to the selector switch. Only one is intact. The rest are broken off just below the top surface. I can now easliy get at the rest, splice on new lengths then pull them all back up to their proper positions. I will have to procure some lamps. I could use 3 of them.

Interesting to note that the push button light is frosted and has a cap of black paint on its nose. I am sure this one would best be diffused a bit.

[Raleigh]

Good information about the bulbs. None of mine were frosted or had a black cap. That might be something to try, especially for the 1940 models with the red buttons.

[MarkBardenwerper]

Correction. According to a photo borrowed from here,
http://antiqueradios.com/forums/viewtopi...69&start=0
they are both frosted, but the one with the black painted tip is on top. Mine is not original, has one unfrosted replacement bulb. One of the beauties of that other restoration was that it was so original when badrestorer started

[MarkBardenwerper]

I checked connections, added a power cord and fired the 285 up yesterday. Got glow on all tubes. Dial lights work. Got some weak reception at first, but by the time I reached for a screw driver to tweek the alignment screws, she went quiet. Get chiffs when I change bands. something is not oscillating. When it was working, tone and volume worked smoothly. I don't think the problem is drastic.

[codefox1]

Still looks like a lot of ancient parts. Recap and recarb is what I would do.

[MarkBardenwerper]

Of course, you are absolutely right. I have one been advantage in that most of the rebuild bits can be scarfed out of my donor chassis, then dropped one at a time into the 285. I will have to be watchful for variations, but I don't think there are many, except in the area of the additional tube.

I  also should be able to use some of the caps that were installed in this one. I will check for suitability first. But I sill need to start off with a parts want list.

This is my first foray onto radio repair, so I will have to rely mostly on completely new or tested components. What could go wrong?

[MarkBardenwerper]

I've pretty much completed the semi-conductor list for my project. I used the 41-255 parts list as a basis. I have not found any parts discrepancies so far. But I do have a question. In the 255 diagram, part 57, a .003 mfd condensor, goes from the white wire leading to the output transformer (58) and to ground. On the black lead, there is part 68, another .003 mfd. condensor going to ground.

In the 285 diagram, condensor 57 does not go to ground but to the black wire. 68 seems to be eliminated. Could someone please confirm the value of 57 in a 285? Out of curiosity, why the difference? Is there a possibility I should not use this variation due to my using the much smaller speaker from the 250?