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Very early Mullard EL84s with O-getters?

I have two coin-based O-getter EL84s, with no holes in the plates. One tube is branded El-Menco and the other is branded Siemens. The El-Menco shows "Gt Britain" and "164-519" in white print. There are no etched production codes visible on either tube.

My limited understanding is that the earliest Mullard EL84s had coin bases and a "1608" designation (pre rX1). There were a few different factory codes, all indicating 1954 as the year of manufacture. At least some of those tubes (F4 factory code), had no holes in the plate.

The coin base would suggest very early production, but the O-getter, as opposed to disc or square, seems inconsistent with that. Thanks for any helpful comments.
bilbar
bilbar OP
5 posts
 
I should clarify, these tubes have a glass base.
mechans
3,048 posts
 
Ah Uhhm....I think you better do some research re Charly before trying to speak with him.

The 50s quad of Mullards I own all have small halo getters and Mullard type code etched in the glass. Try Tube Asylum it's easy to upload a picture and the fund of knowledge very broad indeed.
BTW If your tube was a 7591, an EL 84 variant,it would have a plastic base, however it is a bigger base than a wafer or coin base. The 7591 is not a direct sub, due to a different pinout,
bilbar OP
5 posts
 
Yes, I saw the news about Charlie.

These are definitely EL84 tubes. The missing clues are the production codes. The closest I have found to a similar tube is a photo at tube-classics.de. That tube is Mullard-branded with factory codes indicating it was made at Suresnes, France in 1954.
Post removed 
mechans
3,048 posts
 
Yes Viridian you are right I get those two confused. The one tube I need most is a real pain. Its the 7868 I know that number. The problem is that with a few notable exceptions I think that the counterfiet expensive 1940 -1980 tube replicas I have, sound much better than the new production replicas.
The old production 7868 is approaching EL-34 prices and aren't matched. You may say -"so what?" that isn't critical but in the Sherwoods I own they caution that the 2 tubes in each channel must match. I tried a mixed pair once and watched one tube lit up nicely as it should whereas the other did the crispy critter in less than a second or two.
Fortunately the amp suffered no injury I could find. The good part is that it will operate well enough with two matched pairs but it's tough.
The new production 7868 is too fat for the space that this amp provides.
I can't find any old 7189 readily in matched pairs either for a different amp.
I have quads of EL-84s but not these fancy jobbers and I am unwilling in fact unable to pay out the schnoz . I better sell some of my redundant tubes like 120 + 6SN7s. I need a total of five if I were to keep all the amps and pres I have what a but I really am going to sell this stuff. If I do sell all those amps except one that is a pre with really good tubes in there. That would leave me with still around 100 with 3 or 4 pairs as back ups.
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