Is this a 5-pin ceramic disc capacitor?

[Cifrocco]

I have an old tube radio, a small cheap unit that I wanted to fool around with, disassembling it and rebuilding it on some kind of educationally-friendly proto-board or something. The radio is shown in the attached photos.

At one end of the radio, underneath where the components are connected by tie-points on terminal strips, there is this flat, square component that looks a lot like a disc capacitor but it has 5 pins. I haven't finished sketching the schematic for the whole circuit so I still don't know what its purpose could be.

Do any of you have any ideas what device that is? The photos show where I extracted it from. The photo of the device itself is blurry (sorry), but the inscription on the device says "44" in one corner, then "PCO6" across the face and finally the terminals are numbered 1 to 5. Nothing on the backside.

Resistance measurements between some pins is roughly 50K-ohms but then across others it is infinite. Capacitance measurements also vary between pin sets and also fluctuate a good deal.

 

[hotwaterwizard]

Looks Like it has Motorola PC06 Printed on it is this correct?

 

[hotwaterwizard]

Do you have a Make and Model number for the Radio? We may be able to get you a Schematic.

 

[Funny NYPD]

are there some vacume tube in the pictures?

 

[Cifrocco]

Do you have a Make and Model number for the Radio? We may be able to get you a Schematic.

The radio is a Transonic Model FAD-4 distributed by Transistor World Corp., New York 11, N.Y. USA. Says made in Japan on the back cover. There are 6 tubes and 3 diodes, dual speaker design. The 5-pin part in question is connected in the output stage that uses the 50EH5 pentode.

Thanks for your help.

 

[Papabravo]

New York 11, NY is an address with the old postal zone codes that predate the zip-code which is approaching its 50th birthday.

I remember sending 25 cents "in coin" and a cereal boxtop to Washington 25, DC when I was a kid.

 

[Cifrocco]

Looks Like it has Motorola PC06 Printed on it is this correct?

The photo is too blurred, but no, it's not Motorola's "M" it's actually just the number "44". As for the "PCO6" it could be "PC06" (zero, not an "oh"), I'm not sure.

 

[hotwaterwizard]

I cleared the picture up best I could.
Here is what I came up with.

 

[hotwaterwizard]

**broken link removed**

**broken link removed**

**broken link removed**

Transonic Model FAD-4 AC-DC Operated 6 Tube AM-FM Receiver
Photofact Folder - November 1964
Howard W. Sams & Co., Inc

Sams Set 726 Folser 9

 

[hotwaterwizard]

**broken link removed**

 

[Cifrocco]

**broken link removed**

I'm speechless! Thank you very much. I was so busy googling for 5-pin capacitors with that inscription that it never occurred to me that schematics might still be found for the radio itself, lol.

I am placing my order for the Photofact, today! I'll let you know what I discover about that mysterious part. Thanks again, much appreciated.

 

[Cifrocco]

Just great, the seller on eBay does not ship to Canada. <sigh> What should I do now?!?

 

[hotwaterwizard]

There is another on the Ebay Canada site

**broken link removed**

 

[Cifrocco]

There is another on the Ebay Canada site

**broken link removed**

Canadian eBay has the same seller for that item, with the same shipping restrictions. I don't have patience for that kind of nonsense. I saw that Howard W. Sams still sells such old Photofacts on their website, so I ordered it for $22.00. It will be emailed to me within 1 business day. Can't wait! Thanks again, you have been very helpful.

Now I'm going to shop for some kind of proto-board on which I can rebuild the radio. It will have convenient terminal points where the signals can be measured and analyzed on my scope. My 12-yr old nephew will be thrilled, as will I of course.

 

[hotwaterwizard]

Why would someone put something on a Canadian site that canadians can't buy? Dumb Dumb Dumb

 

[Cifrocco]

I am placing my order for the Photofact, today! I'll let you know what I discover about that mysterious part. Thanks again, much appreciated.

Just received Photofact by email from Sams. Quality isn't the greatest, but I guess that's expected since it's an ancient document. Still, you gotta be impressed that such things even existed.

So, everyone ready for the answer to the quiz?

The device is none other than a "Ratio Detector Network" (never heard of such a thing). It has 2 capacitors and 3 resistors (no wonder DMM measurements were weird). Contrary to what I thought it has little or nothing to do with the output stage and is instead connected across one side of the 10.7MHz IF transformer at the output of the 12BA6 limiter circuit.

It's designated as part K4 on the schematic, enclosed within the dotted lines and known as Transonic part no. Q542D. If anyone has an idea what its function is I'd be delighted to hear it. Thanks.

 

[Roff]

Just received Photofact by email from Sams. Quality isn't the greatest, but I guess that's expected since it's an ancient document. Still, you gotta be impressed that such things even existed.

So, everyone ready for the answer to the quiz?

The device is none other than a "Ratio Detector Network" (never heard of such a thing). It has 2 capacitors and 3 resistors (no wonder DMM measurements were weird). Contrary to what I thought it has little or nothing to do with the output stage and is instead connected across one side of the 10.7MHz IF transformer at the output of the 12BA6 limiter circuit.

It's designated as part K4 on the schematic, enclosed within the dotted lines and known as Transonic part no. Q542D. If anyone has an idea what its function is I'd be delighted to hear it. Thanks.

Google "ratio detector".
It demodulates the FM carrier, with baseband audio as the output.
The part is probably a thick film network. They were usualy made on a ceramic substrate, and conformally coated.