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-   -   ARP12 and AR8 valves (https://www.vintage-radio.net/forum/showthread.php?t=83267)

FERNSEH 3rd May 2012 5:52 pm

ARP12 and AR8 valves
 
2 Attachment(s)
I've had these valves for years and always considered them to be some useless ex-mil types. I'd never find a use for them.

However, I checked out the details of them and in fact they'll be of use someday.
The AR8 is a 2volt double-diode triode and is similar to the Mazda HL23DD.
the ARP12 is a 2volt vari-mu pentode and is similar to the Mazda VP23.
Both have the Mazda Octal base.

www.radiomuseum.org/tubes/tube_arp12.html
www.radiomuseum.org/tubes/tube_ar8.html

The ARP12 has a Mullard look about it. The date or production code on the base is definitely Mullard style. A valve with a Mazda Octal base made by Mullard.

DFWB.

HamishBoxer 3rd May 2012 6:03 pm

Re: ARP12 and AR8 valves
 
They fit I believe a WS 38. Possibly R109.

David

FERNSEH 3rd May 2012 6:05 pm

Re: ARP12 and AR8 valves
 
WW2 equipment?

DFWB.

HamishBoxer 3rd May 2012 6:13 pm

Re: ARP12 and AR8 valves
 
Yes indeed.

G6Tanuki 3rd May 2012 7:03 pm

Re: ARP12 and AR8 valves
 
Typical WWII-era valves - the ARP12 and AR8 were often found alongside the ATP4 in portable transceivers like the WS18, WS38 and WS46.

The manufacturer and date-of-manufacturer can be worked out from the "slash" code - the thing like [KB/D] printed on the envelope.

See http://www.vmarsmanuals.co.uk/newsle.../cv_valves.pdf for how to decode.

-G6Tanuki.

G4XWDJim 3rd May 2012 7:23 pm

Re: ARP12 and AR8 valves
 
I'm just in the process of recreating a 3 valve SW TRF using ARP12s on an OXO tin as chassis donated by Phil, G4SPZ. They're a nice valve and when new look magnificent in their bright gold metalised paint.

They're used in a good many WWII sets. The civilian Invicta 43 has ARP12/VP23s in it.

Jim

Panrock 3rd May 2012 9:08 pm

Re: ARP12 and AR8 valves
 
I think I remember ARP12s in the 88 (or was it 98) sets we had in the Combined Cadet Force at school. One of the channels was blanked off or it would pick up television sound!

All the above offered subject to the vagaries of my dicky memory!

Steve

FERNSEH 3rd May 2012 11:51 pm

Re: ARP12 and AR8 valves
 
As I mentioned in my first post I have had these valves for thirty years or more and often wondered what I could use them for. Now that I know that the ARP12 is a vari mu pentode for 2 volt battery equipment it could be employed as replacement for the VP2 type of pentode. The VP2 and it's equivalents are greedy for filament current, typ. 0.15amp. Also it's becoming a scarce valve. The VP23/ARP12 is much better in having an If of 0.05amp.
The AR8 can replace many 2 volt triodes.

DFWB.

FERNSEH 4th May 2012 12:04 am

Re: ARP12 and AR8 valves
 
Quote:

Originally Posted by G4XWDJim (Post 526752)
I'm just in the process of recreating a 3 valve SW TRF using ARP12s on an OXO tin as chassis donated by Phil, G4SPZ. They're a nice valve and when new look magnificent in their bright gold metalised paint.
Jim

Look forward to seeing it. There seems to be a revival of constructional projects.

DFWB.


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