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Mullard GZ-34 F31 smooth plate ID

70.95.220.92

Posted on March 7, 2023 at 09:46:57
SoCalAl
Audiophile

Posts: 24
Location: So.Cal
Joined: April 29, 2004



I'd like to ID a Mullard F31 smooth plate. No etched code, taller flat top with a dimple, looks like a Philips with a fat base. Identical internal construction (to my eye) to another F31 date code B8D, this tube also has the dome top consistent with a Blackburn F31. The base on each are slightly different.
Is this other tube a Sittard GZ-34 with a fat base?

 

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RE: Mullard GZ-34 F31 smooth plate ID, posted on March 7, 2023 at 19:09:02
opalize
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Posts: 104
Location: NorCal
Joined: March 18, 2021
Probably just a very faint etched code. Have you tried fogging with your breath? Scrutinized in full sunlight?

 

RE: Mullard GZ-34 F31 smooth plate ID, posted on March 8, 2023 at 05:10:35
dogscanskate
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  Since:
August 25, 2023
I see f31, B81 code on the tube at the left. Blackburn, 158/68 or 78 probably 31st week???

 

RE: Mullard GZ-34 F31 smooth plate ID, posted on March 8, 2023 at 05:11:39
dogscanskate
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Location: montreal
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  Since:
August 25, 2023
1958/68 or 78

 

RE: Mullard GZ-34 F31 smooth plate ID, posted on March 8, 2023 at 13:27:19
opalize
Audiophile

Posts: 104
Location: NorCal
Joined: March 18, 2021
"F31" type GZ34 is from 1958. However, I believe the question was regarding the GZ34 on the right, using that '58 Blackburn GZ34 as comparison.

 

RE: Mullard GZ-34 F31 smooth plate ID, posted on March 9, 2023 at 05:36:09
dogscanskate
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Posts: 192
Location: montreal
Joined: May 19, 2004
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  Since:
August 25, 2023
My bad lol. You're absolutely right, I misread the post. I'm still laughing at myself for not reading the OP's post correctly.

 

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