Greetings fellow forum members.
I’m posting this request after months of fruitless web searches.
I’ve got a very small collection of vintage audio valves (around 160 or so). I’m fascinated at the pedigree and history behind this little objects - not just what they can do sonically.
I'm especially interested in the ones made right here in Australia: specifically, Mullard / Philips Miniwatt and AWV.
Now there are plenty of sources of information about date codes for the Mullards / Philips valves manufactured in Hendon, South Australia.
However, I've not been able to find any information about the valves produced in Ashfield, NSW by AWA. The valves themselves are labelled AWV and have date codes etched in their glass. Some examples include:
G1 41 on a 12AU7
YH 20 on a 12AX7
MJ V2 on the base of a 6V6GT
Can any of you experts shed any light?
Many thanks in advance.
I’m posting this request after months of fruitless web searches.
I’ve got a very small collection of vintage audio valves (around 160 or so). I’m fascinated at the pedigree and history behind this little objects - not just what they can do sonically.
I'm especially interested in the ones made right here in Australia: specifically, Mullard / Philips Miniwatt and AWV.
Now there are plenty of sources of information about date codes for the Mullards / Philips valves manufactured in Hendon, South Australia.
However, I've not been able to find any information about the valves produced in Ashfield, NSW by AWA. The valves themselves are labelled AWV and have date codes etched in their glass. Some examples include:
G1 41 on a 12AU7
YH 20 on a 12AX7
MJ V2 on the base of a 6V6GT
Can any of you experts shed any light?
Many thanks in advance.
I haven't been able to foind out AWV valve date codes either. But bear in mind that AWV sold a lot more types than they made. So did the others. AWV imported a lot of RCA US-made tubes, and made just a small preferred range themselves, albiet in vast quantities. The RCA tubes were branded AWV. Their early catalogs actually identified which types were made in AWV and which types were imported from RCA. In a few unusual cases, AWV exported tubes back to RCA! Tyes include 6AR7 and AV44. Talk about selling ice to eskimos!
What fascinates me is that I have some Mullard branded tubes that for various visual and electrical test reasons I believe were made by AWV. One would think Mullard would back themselves up from Philips European production.
One of the more well known differences that can be indentified by electrical test is the method of control grid winding in RF and converter tubes. The original RCA tubes had variable pitch grids. AWV did not at first have variable pitch grid winders. They approximated it by changing the pitch setting in discrete steps a few times during the winding process.
Another subtle change is in 1.4V battery tubes. RCA (unless with a W suffix as in 3V4W and not 3V4 ) and geniune AWV tubes use J-Wire for filaments. English Mullards have tungsten filaments. You can tell the difference by measuring the resisatnce when cold, 0.5V applied, and 1.8 V applied.
What fascinates me is that I have some Mullard branded tubes that for various visual and electrical test reasons I believe were made by AWV. One would think Mullard would back themselves up from Philips European production.
One of the more well known differences that can be indentified by electrical test is the method of control grid winding in RF and converter tubes. The original RCA tubes had variable pitch grids. AWV did not at first have variable pitch grid winders. They approximated it by changing the pitch setting in discrete steps a few times during the winding process.
Another subtle change is in 1.4V battery tubes. RCA (unless with a W suffix as in 3V4W and not 3V4 ) and geniune AWV tubes use J-Wire for filaments. English Mullards have tungsten filaments. You can tell the difference by measuring the resisatnce when cold, 0.5V applied, and 1.8 V applied.
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12AU7 "G1" could be Gf.
My notes on markings for some AWV marked valves:
12AX7 x1, OH 27 N4 AWV
I have 4x 6DX8 marked AWV that use the common f4 marking.
I'll have a look at my spare valves collection for those three models and see if I have any AWV markings.
Ciao, Tim
My notes on markings for some AWV marked valves:
12AX7 x1, OH 27 N4 AWV
I have 4x 6DX8 marked AWV that use the common f4 marking.
I'll have a look at my spare valves collection for those three models and see if I have any AWV markings.
Ciao, Tim
There maybe something in the Radiotronics Magazines which were produced by the Sydney AWV Factory.
See here:
electron Tube Data sheets - AWV, Amalgamated Wireless Valve Company
Cheers,
Ian
See here:
electron Tube Data sheets - AWV, Amalgamated Wireless Valve Company
Cheers,
Ian
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