I would like to know how a 12AX7 tube that has been stored in a barn in Michigan for over 20 years, having the standard, modern RCA logo and labeled as made in Gr. Britain, could have had its country of manufacture in Serbia? Any thoughts?
Thanks very much.
Gord DeHaan

Do you have any more info on the tube, maybe pictures or markings?

It is quite common for distributors to source tubes in various places and relabel as their own.

I found this info on vacuumtube.com that might explain things.

Frank

EI Electronic Industries, Nis, Serbia

Former state-owned factory, makes all types of electrical products, still making tubes using some old Philips production tooling and equipment. Marketed outside of Serbia by Edicron Electronic Components Ltd, UK. Types in production: 6CA7, 6CG7, 12AT7, 12AX7, 12BH7, 12DW7, EL34, EL519, PL519, KT90, KT99, EL84, EL86, possibly a few others.

Some pictures would be very helpful. Look around the base of the glass, do you see any letters or numbers there?

A lot of "outsourcing" was going on at that time, not all of it "straight up." I have a pair of NOS "Amperex" "6L6GC" tubes from that time period. They carry a stamp of "GT BRITAIN" (not "made in Gt Britain," however), and they are USSR all the way.

They won't hold up in 6L6GC service, either. The plates go cherry. More like 6L6GB's.

Larry

I'd be surprised if any RCA tubes were ever made in Great Britain, and if I saw any so marked, I'd suspect the markings of being bogus.

I think I have come across RCA branded audio tubes that also had the Mullard Blackburn code etched on the tube and had the tell tale Philips seams as well. Who knows who did the re-branding though, I have come across tubes labeled as made in a certain country, where the etched Philips/Mullard code did not agree.

Frank

edit: Lots of info on the net if you Google "RCA branded tubes made in Great Britain". Seems it was related to USA import restriction during the cold war, when importing from the Eastern Block was verboten. If the tubes are Mullard or Philips, they will have an etched date and factory code.

It's possible it could be a genuine Mullard.I have
RCA branded ECF80/6BL8's that are actually
Mullards.Also have a Siemens gold pin 6922
that is branded with the old style RCA logo.
Regards,
Swanson

OK, I could believe a tube type that RCA or other US companies didn't make, but 12AX7s were pretty common and I'd expect several US companies like GE and Sylvania were set up to make them. Now whether they had all closed up shop by the 1980s, I don't recall.

RCA closed it's Harrison NJ tube mfgr plant in '76, everything after that point has to be from another source...

I have a RCA branded 5AR4 from Great Brittan that I believe is a Mullard...


Tom

I'd have to dig it out of the tube black hole, but I have an RCA branded 12AX7 made in Hungary.

Thank you all. It was news to me, but it looks like if someone were a fan of the 12AX7 then it is somewhat common knowledge.
Gord

You can sometimes determine who made a tube based on the internal construction and details. Sometimes tiny details, like if some tabs are square or round, the shape of the mica insulators, plate pattern, getter, etc. I have used photos on ebay of good resolution for comparison when I had no example at hand.

http://www.ebay.com/itm/221009555904?ss ... 1423.l2649

The tube in question that the OP is asking about is identical in appearance and structure to the tubes listed in the auction above. There are no markings on the tube other than what you can see in the photos. No etched codes of any kind nor are there any markings on the base between the pins.

Those 12AX7's were definitely made by Ei
in the former Yugoslavia.Back in the early
1990's I used to be able to buy those tubes
for just a few dollars each.They are good tubes
and are starting to get sort of expensive
because they are no longer made and
remaining stocks are getting scarce.
Regards,

The eBay seller claims the factory was destroyed, not the case, they are still operating. They have used a variety of Telefunken and Philips production equipment in the past.

http://www.eierc.com/rc/who_we_are.htm

Frank

In the 1980s and 1990s I subscribed to several limited-circulation audio magazines, though I wasn't buying tubes myself (I had all I needed). I recall reports of hanky-panky by one or more distributors, one of which rebranded Eastern-bloc tubes for sale to the US military.

I don't know when RCA stopped distributing tubes, but I'd expect it was not long after closing the Harrison plant. Just a guess however.

Alan, et al,

First, a bit of older history...

RCA did indeed import a few European types. RCA never made 5AR4s and sold either Sylvania's or Mullard's. RCA never made 6DJ8s or 6922s. Most of these are Siemens, but one also sees Holland and Great Britain. (RCA's own failed 6DJ8 was the 6FW8)

After RCA stopped making tubes in '76, they continued to sell tubes into at least the early 1980s. Alan, your suspicion of bogus tubes is almost on the mark. It appears to me in this late period, RCA's chief supplier of tubes of foreign origin was International Components Corp (ICC). ICC would print "Great Britain" or "Germany" on anything. The simple test is this... If the tube has a Mullard factory and date code, it is legitimate Mullard. Sometimes these late tubes have Yugoslavian factory codes. Other times they are uncoded. ICC appears to have been pretty indescriminant about what they supplied. Sometimes ICC supplied the "real" thing, but oftentimes not.

ICC appears to be the source of late RCA, Raytheon, and Westinghouse 6L6GCs that are Russian, but rebranded "Germany" or "UK".