Weird Edicron tubes: EF804 & E80F

[jim]

Weird Edicron tubes: EF804 & E80L

Hi,

In my collection I have some Edicron EF804 as well as a few Telefunken EF804S. Also some Edicron E80L and original Philips E80L.
What I noticed is that the Edicrons look quite different to the original EF804 and E80L.
It looks like they both got another base and a different internals...
I'd like to know more about these weird versions.
Any clues?

Thanks,
Jim

 

[JonSnell Electronic]

EF804; EF 804, Tube EF804; Rohre EF 804 ID400, Vacuum Pentode
E80L; E 80L, Tube E80L; Rohre E 80L ID18743, Vacuum Pentode
E80L @ The Valve Museum


Not a lot, if anything, on the odd looking valve base.

 

[DF96]

The Edicrons are almost certainly a different but similar valve mounted on a base converter. For example, the Edicron 'EF804' might actually be a Russian EF86 with its pins rearranged.

Edicron are a British valve dealer/rebrander.

 

[jim]

For example, the Edicron 'EF804' might actually be a Russian EF86 with its pins rearranged.

That's what I thought too by looking at those Russian EF86's.

 

[jim]

I just remembered that I have some 6CL6 tubes in my collection so I grabbed one and compared the two tubes.
I think they are the same.

 

[DF96]

Perhaps. The E80L and 6CL6 have broadly similar characteristics. However, I would be annoyed if I paid for an E80L and received a 6CL6 instead.

 

[jim]

However, I would be annoyed if I paid for an E80L and received a 6CL6 instead.

Fortunately, I got those for free.

 

[Soonerorlater]

The Edicrons are almost certainly a different but similar valve mounted on a base converter. For example, the Edicron 'EF804' might actually be a Russian EF86 with its pins rearranged.

Edicron are a British valve dealer/rebrander.

Similar internally to the CV4086, the flying lead version of the ef86

CV4086 @ The Valve Museum

 

[DF96]

The shiny screen/shield shown in post 1 is classically Russian. Looks quite different from western designs.

 

[GoatGuy]

The shiny screen/shield shown in post 1 is classically Russian. Looks quite different from western designs.

And… quite clearly, the bottom of the bulb is a classic mini pinout, metal-bonded-to-glass. The black base looks like a really crass approximation of the sturdy bakelite of Olde. To me. Ruskie retread.

Now I'll give this: Ruskie tubes can be of surprisingly high quality.

After all, the Russian military (and many civilian sectors) continued (and continue into the present) to use vacuum valves for all sorts of equipment that is too well built and expensive to toss-out-and-replace; the demands of such equipment continue to require "reasonable up-time", so the valves' makers must keep up the quality levels, or risk the wrath of the penny-pinching governmental maintainers.

So.

Even creatively post-packaged onto a pinout changing fake-o socket, the fundamental tube is still likely sound.

But I would imagine that having those close-to-the-grid-pin HF ringing damper resistors is even more important than with just the naked mini-pinout valve.

Just saying,
GoatGuy ✓

 

[DF96]

If I desperately needed an EF804 and someone said they could sell me a Russian EF86 (or any other EF86) mounted on a special base so that it could substitute for an EF804 (in most circuits) then I would probably be happy.

If I thought I was buying an EF804 and that thing arrived I would not be happy.

 

[GoatGuy]

Looked up the EF804 on pocnet. Remarkably low-tension and low current. The german manual seems to indicate that most of the time, I_A less than 1.0 ma is the design point. Interesting pentode, actually. I see what you mean (if you needed a real one, then the substitute is poor) GoatGuy

 

[jim]

And… quite clearly, the bottom of the bulb is a classic mini pinout, metal-bonded-to-glass. The black base looks like a really crass approximation of the sturdy bakelite of Olde. To me. Ruskie retread.GoatGuy

Here's a picture of the base. Some red substance is visible behind the second glass base.
And another close-up of the plate structure. Looks definitely like the russian 'EF86'.

 

[Kay Pirinha]

Using a good magnifying lens, you might be able to trace the real pinout of the valve that sits on top of this mysterious thang, and then compare it with the pinout of a EF804 on one hand and a EF86 on the other.


Best regards!