VR102 Valve

[pwdrive]

Anyone tried substituting the VR102(BL63) with a 6F8?

The 6F8 seems to have the same pinout as the VR102.

The 6F8 also seems to be in vogue with the audio brigade.

Lawrence.

[Andy M0FYA]

That's an interesting question, Lawrence!
That's not a valve I have come across before.
The RCA datasheet I just found in the web says each half of the 6F8 has the same characteristic curves as a 6J5.
Andy

[pwdrive]

That's an interesting question, Lawrence!
That's not a valve I have come across before.
The RCA datasheet I just found in the web says each half of the 6F8 has the same characteristic curves as a 6J5.
Andy

Hi Andy, I came across the 6F8 when trying to see if there was a substitute for the elusive BL63/VR102, I found the basic data in my Radio Vlave Data book (Iliffe) Saw your question on another forum, the VR102 seems to be a one off application so far as I know.

6F8 =
Heater: 6.3v@.6A
Va: 250v
Vg: -8v
Ia: 9 ma
Ra: 7.7k
Ma/V: 2.6

Base:

1: m
2: h
3: a1
4: k1
5: g(2)
6: a(2)
7: h
8: k(2)
T.C: g1

I don't know if the BL63 is working in my receiver as I have not delved into the DF section as yet.

Lawrence.

[Joe]

Why is it a VR102 instead of CV-something?

- Joe

[pwdrive]

Why is it a VR102 instead of CV-something?

- Joe

VR denotes RAF Air Ministry I think, the CV number was CV1102, this valve so far as I can ascertain was a one off for the R1155, I think the reason for it's escalating price is part due to the fact that the Audiophools have Hijacked them along with it's nearest substitute the 6F8, on Ebay they are doing 6F8 adaptors complete with top cap fly lead.

Lawrence.

[tiv48]

i dont know of any audio amps that use vr102 or 6f8?
rob t

[Andy M0FYA]

Lawrence, whilst I've never come across anything but the R1155 which uses the VR102, I think that if the valve had been made specially for the Air Ministry then it wouldn't have been given the BL63 identity as well - that's very much a civilian number, which I'm guessing came before the VR102 identity.
We need a prewar valve data book which includes it - anybody got one?
Andy

[Mark R]

TDSL only give the BL63 as a substitute

[Joe]

From the Valve Museum:-

The VR102 (= MOV Type BL63) is a low-impedance double triode with one grid taken to the top cap.

The VR102 was supplied by MOV to the RAF during WW2. Thanks to Frank Whitby for confirming that the VR102 was used for the R1155 receiver that was fitted to Lancaster and other bombers. As part of the Direction Finding circuitry, it formed the visual meter switch operating at either 30 or 80 Hz. Its output fed the twin-needled Visual Indicator and one of these instruments was usually fitted on the top of the cockpit instrument panel.

A description of this clever circuit, designed by the Marconi Wireless & Telegraph Co. is given in the Manual for the R1155 (AP2548A Vol I Chapter 2). This can be seen on the Vintage and Military Amateur Radio Society's website.

The classic envelope is 42 mm in diameter and, excluding the IO base pins, is 113 mm tall.

And under BL63:-

The BL63 was supplied by MOV to the RAF during WW2 normally as the VR102.

I would take this as meaning that it was a pre-existing type - not that I claim any knowledge in this area.

- Joe

[Mark R]

Every valve book I have does not list the VR102