Light bulb limiter

[TIMBO]

Hi guys, I always use the light bulb limiter to check for shorts.
On an 18w build I used it on first fire up and all was good.
But found when played on full power there was problem similar to blocking distortion but worse.
Tried all sorts of things, came to the conclusion that some of the wiring needed to be fixed (I didn't build it) so the turret board was removed.
So I decided to do a bit of transformer checking...
OT Checks good.
PT when disconnected from sockets etc (only mains connected) LBL has a faint glow, I would think that there would be NO glow at all???
But if there was an internal short it would trip the earth leakage breaker.
 
 

[2deaf]

Wall to light bulb then to one end of primary winding and the other end of the primary winding going to the other wall contact?

[TIMBO]

YEP
No secondary's connected to anything.

[sluckey]

There is always current flow even with only the primary connected across the line. It is just a coil of wire. So, depending on the particular PT and the size of the bulb in the limiter, I think that's normal.

I bet you have several PTs on the shelf. Put some on the bench a plug 'em into the limiter. Nothing else connected. Do some of them light the limiter?

[TIMBO]

Thanks guys, I'll say at this time the PT OK.
I was just trying to rule it out.
After removing the turret board I decided to redo the heater wiring, it's a heavy gauge cloth wire and frayed at the ends.
On removing this it appeared to be pushed up against pin6 on a 12AX7 with only a thin bit cloth between the heater wire and the socket pin.
So I think I found the problem....maybe

[kagliostro]

Franco

[TIMBO]

Thanks Franco.