2. amps-preamps
  3. 1249611094

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
racamuti's avatar
racamuti
362 posts
 
Those must be some rare tubes! I've never seen EL84's with a coin base. Maybe a tube expert here will know about these.
If nobody answers you should give Charley a call at Vacuum Tube Valley, if anyone should know it would be him.
Good Luck, Tish
bilbar OP
5 posts
 
Thanks for that tip! I have some photos of them on photobucket. Can I post links here?
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.
More to discover