It's a
pity there never was a double-beam 'scope in the 580 seires. Now
that would be serious fun.
Oooooh yes. With storage, too. :)
Actually a storage version of the 555 would be fun. The only storage
'scope I know of in this series (and I don't have one) is the 549, which
is a storage 545 IIRC.
Incidentally, if you get a chance, l ook at hte 564 'scope manual, in
particualr the storage system scheamtic. The cleaning lady mopping up the
water put there by the flood gun is a classic...
I thought
EB91s (6AL5s, whatever) went on for ever...
Nope, not this one. It had an open filament. "Gee, why is this tube
cold?" :-)
Eek.... One of the few times a vlave tester would have been reliable in
finding the fault (see another thread). On the other hand, it's not hard
to check the reisstnace between pins 3 and 4 with an ohmmeter.
Years ago over here there was a simple battery + bulb continuity tester
sold with varios valve sockets on it, The tester was wired to the heater
pins of the sockets (pins 4 and 5 of the B9A, pins 3 and 4 of a B7G, and
a segond B7G with 1 and 7 wires 'for battery valves only' and so on. It's
actualyl quite useful for weeding out totally dead valves before you use
the AVO Mk 4 or Tekky 570 ;-)
-tony
