[phil vanderoef]

Here's a puzzler - I bought a Philco 37-610 - its chassis has 6 tubes, including a 5Y3(not a 5Y4). There is no tube mounted on top of the transformer. I can't find a schematic anywhere for it. They almost all have either 5 tubes or they have a 5Y4 mounted on top of the transformer - I'm going crazy trying to find a schematic for it. Any help would be greatly appreciated. Thanks, Phil

[AI2V]

"its chassis has 6 tubes"


***The 5Y3 is a common modification when the transformer develops a high voltage breakdown in the filament winding. Don't try to wire it back to a 5Y4. It may measure OK with a multimeter but will be a short when measured with a high voltage "megger".

What are the tubes in your 37-610? If you have two 6K7's, someone probably exchanged the original chassis with a 37-620 chassis; in that case the extra 6K7 is located on the RF chassis near the 6A8; the 37-620 chassis will also have a three section tuning cap whereas the 37-610 will have only two.

[phil vanderoef]

Pete: My 37-610? chassis came with the following tubes; 6SF5, 6K7, 6A8G, 6V6GT, 5Y3, and a VR90. Again, there's no tube socket on the transformer for a tube......strange, isn't it.... Thanks, Phil

[BDM]

VR90?? Is this a tombstone, or a 37-610T found here?
http://www.tuberadioland.com/images/philco37-610a_3.gif

If it's the "T" version, the rectifier tube is mounted along side the transformer, not on top. If this is a tombstone, some swapped chassis. BTW, as Pete stated, you'd have two(2) 6K7 tubes if it's truly a 6 tuber.

[AI2V]

You've got a handful of mods in your 37-610.

The VR-90 is a gas voltage regulator, 90 volts; I have no idea why you would need a regulated 90v in that radio.

The 6SF5 is another mystery but it most likely is used as a first audio amplifier after the detector; normally the 6Q7 performs this task as well as AM detection and AGC. In your case I suspect that someone has installed two solid-state detector diodes ( a simple mod) and rewired it for the 6SF5 which doesn't have any detector/AGC plates.

With your ohmmeter in diode resistance mode (and the radio unplugged!), measure from the junction of R35/R36 to ground; reverse the test leads and measure again. If there's a major difference in resistance you have a solid state detector diode connected to that junction, and probably another diode connected to C37. These diodes will look like small resistors with one band or clear glass with one band. I must admit that I have done this modification before when I didn't have a replacement 6Q7 tube; it can improve sensitivity and audio fidelity to some degree. If your chassis has been solid-stated it might be wise to just leave it alone. Otherwise you will have to rewire the 6Q7 circuit by schematic.

Another comment on the VR90: it's probably a 0B3 and you should probably just take it out and see what happens. Somewhere in the B+ line you will probably find a resistor in series with pin 5 (if it's an octal tube). The purpose is to give a regulated 90 volts somewhere or to limit a voltage to 90v across two points. It's unusual to use these tubes in domestic applications- they are mostly used industrially or for special applications. They can also be used in series (usually a VR90 in series with a VR150) to limit the B+ in the case of a replaced power transformer to lower the maximum voltage of the power supply B+. In custom applications (like my 37-620) I use two VR150's but this is NOT a normal thing to do in a Philco and I don't recommend it for a variety of reasons.

[BDM]

Thanks for explaining it. I was thinking voltage regulator (VR), just kind of through me since I've never heard of this tube.

[phil vanderoef]

Thanks to all who replied - I think this chassis is beyond my expertise - its a shame because the cabinet(a ture 37-610) is in absolutely gorgeous condition. Does any one know of someone who would be interested in buying this Philco table radio? Thanks again, Phil

[Ron Ramirez]

Hi Phil

Please place an ad in the Philco For Sale Or Trade section here - I'm sure you won't have any trouble selling it, if that is what you wish to do.

Sorry to hear you do not feel comfortable in repairing this one. It undoubtedly can be brought back, but it does sound like it is going to take a bit of work.

[Doug Houston]

I gots a better idea. All of this sounds like you may not even have the correct chassis, though some "engineer" could have hacked the original chassis to pieces.

I have a couple of '37 chassis laying around here somewhere, and I could check to see if teither isthe right one. If one of them is, you can have it for the shipping. And also, I'd supply pictures just to let you see if you'd want it.

If the chassis you have is a butchered original chassis, and if what I have is restorable, you'd need to scramble parts between the two, and end up with the right electronics. E-mail me if yo're interested.

[phil vanderoef]

Doug: Yes, I would very much appreciate that. Thanks..........Phil Vanderoef

[phil vanderoef]

I gots a better idea. All of this sounds like you may not even have the correct chassis, though some "engineer" could have hacked the original chassis to pieces.

I have a couple of '37 chassis laying around here somewhere, and I could check to see if teither isthe right one. If one of them is, you can have it for the shipping. And also, I'd supply pictures just to let you see if you'd want it.

If the chassis you have is a butchered original chassis, and if what I have is restorable, you'd need to scramble parts between the two, and end up with the right electronics. E-mail me if yo're interested.

Doug: Yes, I would be very grateful if you did that. Thanks.....Phil Vanderoef

[Ron Ramirez]

Phil, you might send Doug an e-mail.

Doug is one of the great guys in this hobby, without a doubt.

[Doug Houston]

He's in luck. The chassis is totally intact, even to the bottom cover. No cream puff, but all there. This thing has been kicking around here for a couple of years, and now somebody can use it. A teeny bit of space cleared! Just shows to go ya, don't throw usable things out.

I see that the code 122 sets had the 5Y4 on the chassis, and not on the power transformer. I think that Jefferson Transformer built a lot, if not all, of Philco's transformers. Possibly, Philco could have gotten a sweet deal on a production run of conventional transformers?

[Texasrocker]

I also have a spare 37-610 chassis ( minus pwr trans) in case any more orig parts are needed. Will be glad to help also for actual cost of shipping only if I can be of help just lemme know! Those 37-610s are great performers indeed!!