The tube are 6an7 6av6 6ba6 6m5 6x4

Chassis model appears to be 645 (or 845), possibly with a 4th digit. It's abit hard to tell with the smeared printing.

Problem appears to be with the 6ba6, (replaced with same tube and 6k4p). Any recomendations for dirrections to proceed in would be appreciated

If we knew what it was doing or not doing, that would be useful.

A Nipper with that line up is likely to be some thing like 61-51. That will be inked on the chassis right rear.

With the 6AN7 I think that may be model 65-34 of 1966?

But at 1966 would it still be considered a "Nipper"?

Even the Transistor one in the same case as the valve one was a "Nipper".

Sorry for the lack of clarity

I referred to the 6ba6 being the problem, that the tube simply did not function (no glow irrespective of which tube is used ^_^).

This is from memory as the unit's not infront of me now.

The Heater current hits pin 3, pin 4 output is joined with 1 & 7 (heater, grid 1 and cathode?) and then to the chassis.

The unit appears to be the same as this model 64-52 from a cosmetic viewpoint, but since I'm not a member I can't get access to enlarged pictures to confirm it.

http://www.radiomuseum.org/r/hismasters_little_nipper_64_52.html.

The unit appears to be the same as this model 64-52 from a cosmetic viewpoint

Re the valve line-up you quoted, is that what the chassis location sticker itself shows?

You'll note that the 64-52 has a 7-pin 6BE6 in the first stage, but you have quoted a 9-pin 6AN7.

Pins 4 and 5 of a 6AN7 are heater. Pin 3 is cathode.

If that is the case there is every likelyhood a valve /s is in the wrong place, or it's being read wrong.

6BA6 is a 7 pin The heaters are pins 3&4 if 1 is joined to 7 thats a grid to cathode short. 2 to 7 I would believe.

The only valve likely to have two adjacent pins wired together is the 6AV6 and they would be pins 5&6 Its heaters are 3&4.

6AN7.... 9 Pin
6M5 .....9 Pin
6X4 ..... 7Pin Heaters 3&4. Plates 1&6 K 7 (B+ out will have a filter cap on it.

I would expect from left looking at the back 6AN7 next to tuner, 6BA6 between IF cans, 6AV6 possibly with a shield Then the 6M5 & 6X4.


Always pays to check an unknown radio, before you switch it on.

If you wish to valve jockey the tubes to see if the heaters work. remove the 6X4 so that there is no B+.
An open circuit heter can be established with an ohm meter (no fingers on either probes, or pins)

GTC : From a cosmetic viewpoint, it's the same (atleast to the best I can tell from those pictures). It's a different tube layout though - as I listed (I didn't see the tube layout diagram earlier- sorry).

Have all the correct tubes according to tube layout diagram pinted in case (and all are functioning, where tested in other units prior to powerup oringinally).

The heater, grid 1 and cathode pin's where as I said from memory. Memory can be wrong, shouldn't have posted till I had the unit open infront of me. Marcc was dead on the money.

actual pinout-

1 - to 4 on IF1
2- chassis
3 - heater
4 - to pin 7 and the 2 and hense chassis
5 - to pin 1 on IF2
6 - to pin 3 on IF2 via resistor (red red orange - 22k) and pin 1 6an7
7 - to pin 2,5 and chassis

I really have made a poor showing of myself posting here, not used to asking for "help" in this manner - Thanks for your patience.

So, what have we decided the model number is?

We haven't from my end. There were very few early ones that used 6AN7. I suspect its later in the fifties & not in AORSM's

The only combination I can find of 6AN7 and 6X4 is chassis type 65 as mentioned above.

However, seems I don't understand this bit ...

7 - to pin 2,5 and chassis

... because if that's the wiring on a 6BA6 socket, then we appear to have anode (pin 5) shorted to chassis?