Hi I have this valve which I'm trying to identify.
I bought a JJ Tesla ecc83 from Watford valves a while back , but I don't think it's that as there is no red writing on it. Which means it might have come out of the Hartke LH500 which I leant to @D0gS0litud3
Any ideas?
Has a little radar dish shaped thing inside on top,
Letters I can make out are
U3S1B
And
503