7189 - How can I Identify them?

[AJD1964]

Hello Tube pros!

I found 2 what I think are 7189 tubes, but the normal markings are no longer visible. I think that's what they are, but they could be 6BQ5's.

The only markings I can see are vey small toward the bottom of the tubes; one has rX3/X9E, and the other has rX3/40H1.

Is there a way to know by these clues? I can post pics if necessary.

Thanks!

 

[audiodon]

I've found telefunkens and amperex tubes hard to distinguish because the lettering comes off. For those, I've given up and use them as 6BQ5s.
Sylvanias are easy because the lettering is etched.
Hope this helps.

 

[AJD1964]

I've found telefunkens and amperex tubes hard to distinguish because the lettering comes off. For those, I've given up and use them as 6BQ5s.
Sylvanias are easy because the lettering is etched.
Hope this helps.

Well they are Amperex because I can barely see the image of the "tube-guy" blowing the trumpet.

...and I have GE 7189's but they look different inside. I do not want to just test them in the amp, because my circuit calls for 400V on the plate, which will cook them if they're 6BQ5's. I did test them (on 7189 settings) on my Hickock 600A, and they were well over 5000 micro-mohs. I do not know if that's a way to verify.

 

[AJD1964]

Probably these.... 6BQ5. Sure look like 'em inside.
Should have googled first!

 

[analog addict]

Hello Tube pros!

I found 2 what I think are 7189 tubes, but the normal markings are no longer visible. I think that's what they are, but they could be 6BQ5's.

The only markings I can see are vey small toward the bottom of the tubes; one has rX3/X9E, and the other has rX3/40H1.

Is there a way to know by these clues? I can post pics if necessary.

Thanks!

Phillips/Valvo tubes, including Mullard, Amperex, Siemans, etc.

rX3 - EL84
X9E - Sittard Holland, 1959, May
4 (is a sideways triangle) 0H1 - Herleen Holland, 1960, August, week/batch 1

Should prolly have D-getters. Nice tubes. If your Hickok uses the same settings as my 533, 7500 mhos would be considered the minimum value a "new" tube should test

Google is your friend....

http://www.audiotubes.com/mullcode.htm

http://www.tube-classics.de/TC/Tubes/Valvo EL84/EL84.htm

 

[Sam Cogley]

7189s aren't that much different from 6BQ5s. 7189As are where things get out of kilter.

 

[PakProtector]

Decoder Ring:
http://www.audiotubes.com/mullcode.htm

 

[AJD1964]

Thanks for the responses.

The schematic / parts list spec sheet calls for 7189 and 7189A as an alternate. Dang - they're (USA's) not cheap.

On the 6BQ5's I'll re-test them with that set-up, at least I'll know what they are and save them for another resurrection.

Thanks again.

 

[Sam Cogley]

The Soviet 6P14P-EV should sub for 7189 with no problems.