"Ray D. O'Mann" wrote in message
om...
Hi Folks!
Dumb Question #1: How can I test vacuum tubes without a tube tester?
Namely, 6AK6, 6BE6, 6HR6, and 12AX7.
You can check the heater continuity and heater to cathode for shorts
with an ohmmeter. The ohmmeter test won't catch all the shorts, but it
will catch the worst of them. If the metallic deposit on the inside of
the tube's glass has turned white, the tube is full of air and is no
good.
These tubes will probably work if they have good heaters, no bad heater
to cathode shorts and aren't full of air.
You can find out your tube pin outs he
http://hereford.ampr.org/cgi-bin/tube?tube=
Dumb Question #2: Is there a solid-state equivalent to these tubes?
There was one for the 12AX7. It wasn't very popular and probably isn't
worth looking for. If the others have equivelents, they would be even
rarer.
They are from an old Knight Star Roamer that keeps dying.
Dying in what way? Tubes can cause such problems, but I'd first suspect
capacitors, a selenium rectifier, bad connections, and bad resistors.
Dumb Question #3: Is the above worth doing?
It depends. With some effort and maybe a bit of luck, you'll end up
with a working Star Roamer and bit of expirence. Safety is worth
mentioning:
http://repairfaq.org/sam/safety.htm
Check out:
http://antiqueradio.org/howfix.htm
http://antiqueradio.org/recap.htm
Thanks for your help.~~Ray
Frank Dresser