[goldwerger]

I wonder wether anyone has any idea who makes (made) this tube?

no info on it anywhere I can find. perhaps some chinese branding or someplace that went out of business, but I'm curious..

 

[genefruit]

I wonder wether anyone has any idea who makes (made) this tube?

no info on it anywhere I can find. perhaps some chinese branding or someplace that went out of business, but I'm curious..

Google seems to indicate "SUNG CHIANG Co" - http://softone.a.la9.jp/english/vt-1.htm

 

[goldwerger]

Google seems to indicate "SUNG CHIANG Co" - http://softone.a.la9.jp/english/vt-1.htm

yea, that was the same single link I found (anywhere on the internet) nothing else.

thank you!!

 

[elig63]

Hi guys ! Does anyone have experience with these tubes? Which ones are better?
https://wooaudio.com/tubes/sophia-aqua-274b-single
https://www.langrex.co.uk/products/5u4g-brimar-uk-nos-valve-tube-lc76/

 

[Designsfx]

Hi guys ! Does anyone have experience with these tubes? Which ones are better?
https://wooaudio.com/tubes/sophia-aqua-274b-single
https://www.langrex.co.uk/products/5u4g-brimar-uk-nos-valve-tube-lc76/

While I’ve not heard the Brimar’s I do own the Sophia 274B and like it very much. However there is debate on which of the Aqua 274’s sound better- some say the original Aqua (which I own) and others will say the Aqua II (which has the darker blue glass). I’ve also heard comments regarding production issues/early failures with the Aqua II 274B.

 

[JTbbb]

Hello all,

I have acquired this Marconi/GEC? U52 5U4G thinking it might be a copy. A member here thinks it is genuine, so am posting it here for the wider community’s thoughts. The photos are the best I can do, but it has smooth anode plates with a cup getter, and obviously a straight brown base rather than curved. I believe it’s genuine, can anyone add to this? Any idea date of manufacture? Thanks.

 

[gibosi]

In my opinion it was made by Mullard, likely WWII years.

 

[Tubegear]

The top mica plate and hanging filaments are very different from the Mullard 5U4G. I think its fake -> pretty sure its a RCA 5R4GY

 

[JTbbb]

The top mica plate and hanging filaments are very different from the Mullard 5U4G. I think its fake -> pretty sure its a RCA 5R4GY

I was wondering whether it could be RCA etc. but these have ribbed anodes. This from The Valve Museum has similarities, but is earlier. Also the tube from vintage electronics has close similarities.

Oops, missed this pic.

 

[gibosi]

The top mica plate and hanging filaments are very different from the Mullard 5U4G. I think its fake -> pretty sure its a RCA 5R4GY

With "BVA" and "British Made" printed on the glass is is very unlikely that it is US-made. The British 5U4G appears to be based on the FW4/500, a 4-volt rectifier. Four volts, not five, was the standard in Britain and most of Europe before the war. But with the Lend Lease program, the US gave Britain tons of equipement --radios, aircraft and even ships. And this American-made equipment used 5-volt tube rectifiers. It was a simple matter for British manufacturers to change the heater of a FW4/500 to 5 volts and call it a 5U4G. And as was the case with most vacuum tubes, the construction changed over time with feed back from the field and the introduction of new materials and technology. So it's no surprise that older tubes often look different than newer ones.

 

[JTbbb]

With "BVA" and "British Made" printed on the glass is is very unlikely that it is US-made. The British 5U4G appears to be based on the FW4/500, a 4-volt rectifier. Four volts, not five, was the standard in Britain and most of Europe before the war. But with the Lend Lease program, the US gave Britain tons of equipement --radios, aircraft and even ships. And this American-made equipment used 5-volt tube rectifiers. It was a simple matter for British manufacturers to change the heater of a FW4/500 to 5 volts and call it a 5U4G. And as was the case with most vacuum tubes, the construction changed over time with feed back from the field and the introduction of new materials and technology. So it's no surprise that older tubes often look different than newer ones.

Thanks for your detailed reply gibosi, always an interesting and informative read. So on the balance of probability’s this may be an earlier tube rather than a later one?

 

[Toonartist]

@JTbbb knowing the other tubes you bought this with, I find it hard to believe this rectifier is a fake. It would seem an odd thing to do to include it with a bunch of other legit tubes. Also, most fake tubes printed lettering is very bold white and perfectly crisp edges. The printing process on this tube doesn’t. Looks similar to the process used in early Mullard tubes which would be in keeping if this was part of the Marconi brand, which I’d imagine will have used a similar process as other British tubes. I think it’s more about establishing age and whether it was an early sample.

 

[gibosi]

Thanks for your detailed reply gibosi, always an interesting and informative read. So on the balance of probability’s this may be an earlier tube rather than a later one?

With a cup getter and the metal "umbrella spokes" attached to the top mica spacer, it seems to me to be middle to late 1940's. But the brown micanol base suggests early 1950's.... I wonder... Do you see any evivdence of a production code etched into the glass?

 

[JTbbb]

With a cup getter and the metal "umbrella spokes" attached to the top mica spacer, it seems to me to be middle to late 1940's. But the brown micanol base suggests early 1950's.... I wonder... Do you see any evivdence of a production code etched into the glass?

No. But the upside down pan getter is identical to this GEC KT66 1962 vintage.

 

[u2u2]

The top mica plate and hanging filaments are very different from the Mullard 5U4G. I think its fake -> pretty sure its a RCA 5R4GY

I bought several RCA 5R4GY from Langrex several years ago. Really nice performers for the money. I examined the photos and one of my tubes as best I could and they are identical in every feature but for the getter and glass etching. The getter location is the same but my examples have D getters(?). Getters aside, these tubes could have been produced on identical machines to the same specs.