Source of Germanium Transistors NOS

[transmaster]

I need to purchase a set of New/Old stock Germanium transistors for my Zenith Trans-Oceanic Royal 1000, and 3000. I have a number of sources but I wonder if there are any that you out there can turn me onto?

[Findm-Keepm]

Zenith prescribed the following for the transistors in your radios:

Royal 1000:

121-44 2N370
121-45 2N139
121-46 2N109
121-47 2N270
121-48 2N371
121-49 2N372

Royal 3000:

121-44 2N370
121-228 2N1742
121-46 2N109
121-47 2N270
121-48 2N371
121-49 2N372
121-64 2N405
121-230 2N1745
121-137 2N1180
121-138 2N1180
121-139 2N1180

Zenith makes a point - "Due to wide characteristics within any given EIA or manufacturer's number, performance may not be identical to Genuine Zenith Transistors."

Source is Zenith Transistor spec guide 902-656, dtd Feb 1970.

Hope this helps,

[transmaster]

Thanks. I have the equipment to test them, so I am going to try some of the cheap Russian transistors. As long as I install transistors that have the same specifications as the original I should be OK.

[dieseljeep]

Originally Posted by Findm-Keepm

Zenith prescribed the following for the transistors in your radios:

Royal 1000:

121-44 2N370
121-45 2N139
121-46 2N109
121-47 2N270
121-48 2N371
121-49 2N372

Royal 3000:

121-44 2N370
121-228 2N1742
121-46 2N109
121-47 2N270
121-48 2N371
121-49 2N372
121-64 2N405
121-230 2N1745
121-137 2N1180
121-138 2N1180
121-139 2N1180

Zenith makes a point - "Due to wide characteristics within any given EIA or manufacturer's number, performance may not be identical to Genuine Zenith Transistors."

Source is Zenith Transistor spec guide 902-656, dtd Feb 1970.

Hope this helps,

I have a Royal 1000 or so, that one of the audio output transistors was missing. One of those fat, RCA sourced ones..
I have a SK3004 in there now, but it's no where near the original. It's still better than none.

[wa2ise]

I have a Royal 1000 or so, that one of the audio output transistors was missing. One of those fat, RCA sourced ones..

If it's a PNP, one place to find Ge transistors are in old fashioned touch tone Ma Bell phones. In the touch tone keypad.

More at http://videokarma.org/showthread.php?t=260275

You'd need two such phones to get a pair for the audio output stage.

[transmaster]

I have ordered 26 P416A Russian Germanium Transistors from SOVCOM $7.16 cents. and $8.00 dollars postage. They come from Ukraine, Brett the Vender has a 99.9% rating, and he has a good reputation with the folks on the Antique Radio Forum. I am advised they are a very good replacement for the transistors in the RF chain on the Royal 1000, and 3000 in fact as good if not better then the original Amperex transistors Zenith used. They also tell me for some reason the transistors in the FM section on the 3000 are not failure prone which is a good thing as they have not really found a good substitute in the Russian parts, but there is still a bunch that have not been tried.

Be sure to get yourself on of the Cheap Chinese semiconductor testers, $15 bucks you can't loose. They don't give as much information about the transistors state as my Atlas DCA55 but it does tell which lead is what the Hfe, and the mV rating.. Plus is tests, diodes, resistors, capacitors, inductors, and batteries.

[Findm-Keepm]

Originally Posted by transmaster

I have ordered 26 P416A Russian Germanium Transistors from SOVCOM $7.16 cents. and $8.00 dollars postage. They come from Ukraine, Brett the Vender has a 99.9% rating, and he has a good reputation with the folks on the Antique Radio Forum. I am advised they are a very good replacement for the transistors in the RF chain on the Royal 1000, and 3000 in fact as good if not better then the original Amperex transistors Zenith used.

I was under the impression that Zenith used RCA and Mullard semis. The Zenith cross reference lists only one Amperex tranny, not used in the 1000 or 3000. Do you have any transistors so marked? All of mine clearly have RCA's EIA code of 274 on them, with one TO-7 transistor having RCA and 274 marked about 120 degrees opposite each other.

Cheers,

[transmaster]

Originally Posted by Findm-Keepm

I was under the impression that Zenith used RCA and Mullard semis. The Zenith cross reference lists only one Amperex tranny, not used in the 1000 or 3000. Do you have any transistors so marked? All of mine clearly have RCA's EIA code of 274 on them, with one TO-7 transistor having RCA and 274 marked about 120 degrees opposite each other.

Cheers,

This info comes from the Antique Radio Forum the person discussing it said the Zenith marked transistors he had where identical to the Amperex down to the tooling marks, he did not elaborate beyond that. This does not mean Zenith did not use other brands. The ones that are in my 1000, and 3000 seem to be RCA's. I can read the Zenith part number on them but nothing else.

[transmaster]

I ordered the Germanium transistors from SOVCOM 12/20 and they where mailed out on the 12/22. The design is called a tophat transistor as the casing looks like a tophat. Not really sure if I will need them but the bottom line is I will have them.

Merry Christmas everybody!