What is this tube?

mosfetmaniac · 07:53 AM

I have a couple of 1943 Amperex JAN-CEP-120 tubes, NOS in boxes.
It looks like a smaller version of a 211(vt-4c) or 845, the only reference I can find about them is a pair for sale on a chinese website last year.

Does anyone know what they are and/or have any specs?

The picture attatched shows an amperex 211, the cep-120 in the middle and an 845 on the right for scale.

If suitable, they would make a cute SE amp, but replacements could be scarce.

Regards,
Dave.

mobyd · 22nd February 2010, 08:09 AM

Looks a lot like a ZB120 to me
http://tubedata.tigahost.com/tubedat...11/z/ZB120.pdf
M

mosfetmaniac · 22nd February 2010, 08:12 AM

Hey neighbour!, it certainly does and no doubt you know who it came from

mobyd · 22nd February 2010, 08:27 AM

Quote:

Originally Posted by mosfetmaniac

Hey neighbour!, it certainly does and no doubt you know who it came from

Lemme guess :
RNZAF Weedons -> Ferrymead museum -> Lyttelton tube chap -> You
Anyway, got plenty of spares if you do build something
Cheers
M

Arnulf · 22nd February 2010, 08:35 AM

I hope you don't mind me using your topic

Can anyone identify tube in photo ? It is a noval (9-pin) tube, about the same height as EL84, there appear to be few pins unconnected which would indicate a double (FM detector ?) diode. The print has been completely wiped off and the etching doesn't look like anything familiar either. I believe it came from an old radio, although I can't be 100% sure of that. I've never seen a double diode arrangement with anodes perpendicular to one another, sharing same heating element in the center

(photo is 335 KB in size, not dialup friendly)

mobyd · 08:45 AM

If it had 7 pins I'd say 6X4 - 9 pins it probably is an RFT brand 6CA4 aka EZ81
M

azazello · 02:30 PM

Ez81!

Arnulf · 22nd February 2010, 07:54 PM

Wow guys, it never occured to me that those small anodes could take that much current so my assumption was some oddball detector diode, but based on your replies I went searching for photos and came across this one which looks precisely like what I've got here.

This is the kind of EZ81 I was used to seeing, it looks completely different.

mosfetmaniac · 23rd February 2010, 11:08 PM

Quote:

Originally Posted by mobyd

Lemme guess :
RNZAF Weedons -> Ferrymead museum -> Lyttelton tube chap -> You
M

Close enough

Any thoughts so far in their suitability, or has anyone ever heard them working in an Audio amp?

Steerpike · 24th February 2010, 10:15 AM

Quote:

Originally Posted by Arnulf

Can anyone identify tube in photo ? It is a noval (9-pin) tube, about the same height as EL84, there appear to be few pins unconnected

Could be an EZ80, almost the same as the EZ81, but lower crrent.

22nd February 2010, 07:36 AM	#1
mosfetmaniac diyAudio Member Join Date: May 2009	What is this tube? I have a couple of 1943 Amperex JAN-CEP-120 tubes, NOS in boxes. It looks like a smaller version of a 211(vt-4c) or 845, the only reference I can find about them is a pair for sale on a chinese website last year. Does anyone know what they are and/or have any specs? The picture attatched shows an amperex 211, the cep-120 in the middle and an 845 on the right for scale. If suitable, they would make a cute SE amp, but replacements could be scarce. Regards, Dave. __________________ all sorts of stuff Last edited by mosfetmaniac; 22nd February 2010 at 07:53 AM.

22nd February 2010, 08:12 AM	#3
mosfetmaniac diyAudio Member Join Date: May 2009	Hey neighbour!, it certainly does and no doubt you know who it came from __________________ all sorts of stuff

22nd February 2010, 08:41 AM	#6
mobyd diyAudio Member Join Date: Sep 2004 Location: Auckland	If it had 7 pins I'd say 6X4 - 9 pins it probably is an RFT brand 6CA4 aka EZ81 M Last edited by mobyd; 22nd February 2010 at 08:45 AM. Reason: why not

22nd February 2010, 02:26 PM	#7
azazello diyAudio Member Join Date: Aug 2008 Location: Bulgaria	Ez81! Last edited by azazello; 22nd February 2010 at 02:30 PM.

22nd February 2010, 07:54 PM	#8
Arnulf diyAudio Member Join Date: Feb 2009	Wow guys, it never occured to me that those small anodes could take that much current so my assumption was some oddball detector diode, but based on your replies I went searching for photos and came across this one which looks precisely like what I've got here. This is the kind of EZ81 I was used to seeing, it looks completely different. __________________ mod verb, transitive /mod/ to state that one is utterly clueless about the operation of device to be "modded" and into "fixing" things that are not broken; "My new amplifier sounds great so I want to mod it."

22nd February 2010, 08:09 AM	#2
mobyd diyAudio Member Join Date: Sep 2004 Location: Auckland	Looks a lot like a ZB120 to me http://tubedata.tigahost.com/tubedat...11/z/ZB120.pdf M

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