UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > Components and Circuits

Notices

Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

Closed Thread
 
Thread Tools
Old 15th May 2014, 10:59 am   #1
ukcol
Dekatron
 
ukcol's Avatar
 
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,727
Default CV1326 = AC4/Pen ???

Is a CV1326 an EXACT replacement for the AC4/Pen?

In some notes Mike Barker wrote on the Murphy A40C he said,

Quote:-

"Oh, do make sure you have AC4/Pen output valves, Nothing else will do! No, not even those Nasty Mullard PenB4's. If you want the quality you must have the Mazda AC4/Pen's".

End quote.

Although the AC4/Pen valves in my A40C are still serviceable, one of them is only just in the "green zone" when testing emission, which means they are out of balance at the very least.

Langrex had four NOS AC4/pen valves listed in stock and so I ordered 2 yesterday. They arrived today but turned out to be CV1326s.

The National Valve museum lists NEAR equivalents to the CV1326 as AC4/Pen, ARP8, PenB4, CV3526, Pen428 and APR4E.
They also list NEAR equivalents for the AC4/Pen as ARP8 and CV1326.

Frank's Electron Tube Data site lists AC4Pen and ARP8 as near equivalents to the CV1326.

My Bernard Babani Equivalents book lists the AC4/Pen as equivalent to the CV1326 in the CV section, the AC4/Pen is not listed in the commercial valve list.

In view of Mike's comments above I am concerned to find out whether or not the CV1326 is a direct replacement for the AC4/Pen. If not I will return the CV1326s to Langrex and try to source a pair of genuine Mazda AC4/Pen valves.

I am hoping that the CV1326 is a Mazda AC4/Pen made for the military.
__________________
Best Regards,
Colin McLaughlin
BVWS Member

Last edited by ukcol; 15th May 2014 at 11:10 am.
ukcol is offline  
Old 15th May 2014, 12:57 pm   #2
jonnybear
Octode
 
jonnybear's Avatar
 
Join Date: Nov 2010
Location: Cullompton, Devon, UK.
Posts: 1,107
Default Re: CV1326 = AC4/Pen ???

Yes a CV1326 is a AC4/PEN take a glance,http://frank.pocnet.net/other/docs/W...heServices.pdf
John
jonnybear is offline  
Old 15th May 2014, 4:53 pm   #3
ukcol
Dekatron
 
ukcol's Avatar
 
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,727
Default Re: CV1326 = AC4/Pen ???

Thanks for that John, I am somewhat reassured.

I sent an email to Langrex pointing out my concerns and had a reply from James Rhodes. He also assured me that the CV1326 was the direct replacement for the AC4/Pen but said he would still refund me upon return of the CV1326s if I so wished. How is that for good service!

My concern came from lists that say the CV1326 is equivalent to several different valves that I know are, although similar, not the same.
__________________
Best Regards,
Colin McLaughlin
BVWS Member
ukcol is offline  
Old 15th May 2014, 5:25 pm   #4
valvecollector
Hexode
 
Join Date: Jul 2003
Location: Leeds, West Yorkshire, UK.
Posts: 364
Default Re: CV1326 = AC4/Pen ???

The actual EVS (CV) datasheet for CV1326 says the prototype is the 7-pin AC4/Pen. CV specs are generally the same or tighter than the prototype.

James at Langrex is a good bloke.
__________________
Virtual Valve Museum http://www.tubecollector.org/
BVWS member - M6IGP
valvecollector is offline  
Old 15th May 2014, 5:54 pm   #5
ukcol
Dekatron
 
ukcol's Avatar
 
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,727
Default Re: CV1326 = AC4/Pen ???

Thanks Jeremy. BTW is that data sheet available on the net?

Quote:
Originally Posted by valvecollector View Post
James at Langrex is a good bloke.
Agreed.

BTW the CV number is clearly marked on the side of the valves but I have belatedly noticed that the remains of the printing on top of the valves confirm that they are indeed Mazda AC4/PENs.

If I had noticed that before I could have saved everyone a lot of heartache.
__________________
Best Regards,
Colin McLaughlin
BVWS Member
ukcol is offline  
Old 15th May 2014, 10:23 pm   #6
valvecollector
Hexode
 
Join Date: Jul 2003
Location: Leeds, West Yorkshire, UK.
Posts: 364
Default Re: CV1326 = AC4/Pen ???

There were several EVS sheets on Frank's site but now I can't find any! Odd. I scanned my EVS books some time back but I never put the sheets online - may be about time to.

And with nearly 1,500 CV types in my collection I don't have a CV1326...

Ok here's the sheet for CV1326 - note it's also an ARP8. If you want to get bored, the K1001 document referred to by EVS sheets is one I do have online - http://www.tubecollector.org/documents/k1001/
Attached Files
File Type: pdf CV1326.pdf (167.4 KB, 70 views)
__________________
Virtual Valve Museum http://www.tubecollector.org/
BVWS member - M6IGP
valvecollector is offline  
Old 16th May 2014, 8:30 am   #7
ukcol
Dekatron
 
ukcol's Avatar
 
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,727
Default Re: CV1326 = AC4/Pen ???

Thanks very much for the link and the data sheet Jeremy.

I think you also qualify for the "Good Bloke" label.

BTW it is interesting to note that the AC4/Pen is a Beam Tetrode and not a true pentode as the name suggests.
__________________
Best Regards,
Colin McLaughlin
BVWS Member
ukcol is offline  
Old 16th May 2014, 9:56 am   #8
Mr Moose
Heptode
 
Join Date: Jul 2008
Location: Gloucestershire, UK.
Posts: 892
Default Re: CV1326 = AC4/Pen ???

Hello,

Interestingly the Mazda data sheet for the AC4/Pen ( http://frank.pocnet.net/sheets/146/a/AC4-PEN.pdf )gives the heater current as 1.75A, whereas valvecollecor's data sheet for the CV1326 gives it as 2.1A.

Yours Richard
Mr Moose is offline  
Old 16th May 2014, 11:42 am   #9
valvecollector
Hexode
 
Join Date: Jul 2003
Location: Leeds, West Yorkshire, UK.
Posts: 364
Default Re: CV1326 = AC4/Pen ???

Indeed, and the acceptance test says 1.9A to 2.3A. But Colin has a valve with both markings so it would be interesting to see what the actual current drawn is.
__________________
Virtual Valve Museum http://www.tubecollector.org/
BVWS member - M6IGP
valvecollector is offline  
Old 16th May 2014, 1:35 pm   #10
ukcol
Dekatron
 
ukcol's Avatar
 
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,727
Default Re: CV1326 = AC4/Pen ???

I had made the same observation in the documentation.

I have just measured the heater current on both my new CV1326s and it comes out at 1.95Amps for each valve with the mains input trimmed to give 4.00 volts across the heaters. So it looks like my examples are 1.9 amp heaters (well within the range for tolerance and measurement error).
__________________
Best Regards,
Colin McLaughlin
BVWS Member
ukcol is offline  
Old 19th May 2014, 11:31 am   #11
valvecollector
Hexode
 
Join Date: Jul 2003
Location: Leeds, West Yorkshire, UK.
Posts: 364
Default Re: CV1326 = AC4/Pen ???

Sorry I meant to follow this up. I wonder if this means that of all the AC4/Pen's around at the time, for some reason the ones that gained the CV mark were more hungry and others do run down at 1.75A. The type was obsolete when it got the CV number but there might be some history attached to the ARP8 as it appears the ARP8 'carried' the AC4/Pen mark along with it when it became a CV. For some odd reason that kind of history fascinates me...
__________________
Virtual Valve Museum http://www.tubecollector.org/
BVWS member - M6IGP
valvecollector is offline  
Old 19th May 2014, 7:05 pm   #12
ukcol
Dekatron
 
ukcol's Avatar
 
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,727
Default Re: CV1326 = AC4/Pen ???

Hi Jeremy

I have removed 2 old Mazda AC4/PENs from the set; I can measure their heater current if you wish.
__________________
Best Regards,
Colin McLaughlin
BVWS Member
ukcol is offline  
Old 19th May 2014, 8:17 pm   #13
ukcol
Dekatron
 
ukcol's Avatar
 
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,727
Default Re: CV1326 = AC4/Pen ???

I have just measured the heater current of the old valves, one comes out at 1.90 Amps and the other at 1.85 Amps. So it looks like they too have a nominal heater current of 1.9 Amps, which is interesting as they are commercial Mazda AC4/PENs and not CV types.

They were measured under the same conditions as the CV1326s in post 10.
__________________
Best Regards,
Colin McLaughlin
BVWS Member
ukcol is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 5:18 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Copyright ©2002 - 2018, Paul Stenning.