6Q7G Valve, what brand ?

[tri-comp]

Hello,

I've got a pair of NOS 6Q7G valves.
They are both in the original boxes marked Z/CV587.
The valves are marked ZA5691 on the bases which is consistent with CV xref. charts for Army codes.
The valves are w/o any manufactures branding except the bases are also marked:
W↑D
I expect this marking could indicate the manufacturer but I have no idea where to find the relevant information.
Can someone here help, please ?

[snowman_al]

In the UK the WD stands for ''War Department'' the vertical arrow is also part of that logo. The arrow is sometime used alone.

You need more clues if you want to know who made it.

Alan

[turretslug]

I was led to believe that it was simply the uncomfortably Orwellian "War Department", rather than a manufacturer.

[tri-comp]

Thank you, both.
The valves are not marked with anything more on the outside but inside on the base-pinch the glass is marked with what looks like
Y 1 Ø M
The other side of the pinch is not visible because of a strong silvery getter covering about 80% of the inside of the bulb.
There's just enough hole through the getter to see the above marking.
I do know it's NOT a UK Tungsram valve as I also have a NOS 6Q7G of this brand that's clearly made with different tooling.

[G8HQP Dave]

Code Y could indicate that the valve was made at Philips, Sittard. Google 'Philips factory code list'.

[tri-comp]

Dave,

I believe these valves are way back older than what the Philips factory codes will cover.
Also I seriously doubt that Philips ever made a 6Q7G valve at all.
I had a good look around eBay and found some Brimar 6Q7G's for sale and they look exactly like mine.
The font type and size used for engraving the base is also the same.
Here are a few pictures of my single Tungsram and one of the possibly Brimar's.
Look at how differently the top of the valve construction is supported.
In the Tungsram clearly by Mica and in the Brimar by wires.

So, I guess Brimar it is.

/Torben

[RF Burn]

Torben,

In the last photo, the type number is shown in an octagon, this is typical of the marking used on USA manufactured valves of that era. I suggest it could therefore be an RCA product.

Does the base have the words "Licensed to extent indicated on carton" embosed around the bottom of the base? I believe that this was only used by USA companies on their products.

Brimar consumer valves of that era could well be USA imports, remarked and sold by them. I have many examples here of that scenario.

Adrian

[G8HQP Dave]

6Q7G appears in the Philips list, so at some time they either made them or had them made for them.

Brimar used a numeric code.

Details of internal construction changed from time to time.

The box may have a code for the maker; there were a separate set of codes used for CV valves. Hence you may find the official military code for the maker on the box, and a quite different private code for the maker on the valve. For example KB/DA on the box means Mullard at Blackburn; on the valve this is indicated by the date code beginning with B. Mullard Mitcham is KB/D on the box and R on the valve. See https://www.tubecollector.org/cv-valves.htm.

[tri-comp]

The Octagon could indeed point to the US.
I have other valves with the typenumber put inside an octagon, like a Sylvania 1625 (807-variant).
I'll see if I have any RCA's marked in a similar way.
I don't remember ever seeing G-E doing this.
There are no more marking on the valves, the bases and the boxes other that what's already been shown or discussed.

Mullard made the 6Q7G but again it's looking very much different from my unknown/Brimar.
Possibly they supplied Philips with the type ?

[snowman_al]

My guess is it is an early version from BRIMAR.
Look at the top mica support structure, it has metal fingers and pig tail g1 connection... and they used the hexagon too.

Like this?

http://www.r-type.org/exhib/abw0002.htm

Alan

[tri-comp]

Exactly, Alan but Adrian/RF_Burn could still be right about the valves being a rebranded import from the US.
I'll go through my valves tonight and see if I can find other than Sylvania's with the Octagon. I SHOULD have some RCA's...

/Torben

[cathoderay57]

I can't read all of the labels on the valve boxes but the packaging looks very much like these came from government stock. There might be a clue on the those labels as to manufacturer but, if present, you would need info to decode it. In recent years the NATO logistics organisations use a 5 digit code known as an NCAGE code (NATO Commercial And Government Entity), which can be interpreted to reveal name, address and contact details of supplier. I suspect these valves were labelled a long time before that system was introduced. Cheers, Jerry

[G8HQP Dave]

Mullard and Philips have been the same company since well before the 6Q7 was developed. However, I agree that the valve labelling looks like US origin. Not surprising as 6Q7 is a US design, although probably made over here too.

[tri-comp]

My first RCA find with Octagons around the typeno. is the 829B & JAN CRC-829B.
Having turned that box upside down another 829B with the Octagon symbol fell out. It's a CIFTE branded 829B and you might suspect it's an RCA rebrand but I don't know about that. The above RCA's 829B & JAN CRC-829B' are 100% the same build. The CIFTE however is NOT made like the RCA's. A major difference is that the upper end of the valve-structure is supported by a large Mica-disc in the CIFTE that's missing entirely from RCA's. Bottom Mica's are shaped differently between the two brands as well.
So, was the Octagon also used on European produced valves ?
Another RCA 829 surfaced. This is the original 829, not 829B and it hasn't got an Octagon, so that probably says something about when RCA started using the Octagon-marking.

I believe I've decided my 6Q7G is a Brimar until someone proves otherwise.
Then again it's not a matter of life and death.

[snowman_al]

tri-comp, does your 'unknown' example have an ''N'' moulded in the base, a small hole by the spigot key and a ridge round the edge of the base by any chance?
Alan

Cross posts, yes, the octagon is / was used by Brimar on 'Made in England' valves.

[tri-comp]

Originally Posted by snowman_al

tri-comp, does your 'unknown' example have an ''N'' moulded in the base, a small hole by the spigot key and a ridge round the edge of the base by any chance?
Alan

Alan,
Yes, it has exactly that.

The box-label has no information other than what you see on the photos.
The end-label has absolutely the same info as the top-label as they are infact 2 separate identical adhesive labels likely from a roll.

[snowman_al]

Brimar

[G8HQP Dave]

Just noticed the Z on the box. Could this mean Marconi-Osram manufacture in Hammersmith?

[tri-comp]

OK, so I owe it to the letter "N" and a small hole in the bottom to have it identified as a Brimar.
I suppose stranger things have happened !

Thank you, all

/Torben

[Maarten]

Originally Posted by G8HQP Dave

Code Y could indicate that the valve was made at Philips, Sittard. Google 'Philips factory code list'.

Y10M doesn't decode as Philips. Also, Philips printed their codes on the base or on the outside of the glass.