RadioBanter - View Single Post - HELP..COLLINS 30L-1

December 2nd 04, 04:36 AM

wrote:
I hope that I can get some ideas of my problems with my
30L-1...It was out of use for awhile, and I brought it up very slowly,
and all lookes fine..worked for about a day, but now when I drive it
even lightly, and dip the final with the tune control and very light
loading, even with very minimal drive, it pops the primary fuse.snip
Hi, Bob

It's not wise to operate the 30L-1 at minimal loading
(loading capacitor maxed) - you will run excessive grid current.
Tune up with a small amount amount of drive, using the tune meter,
per the manual. Then, run a reduced amount of drive if you want to keep
the power low.

I was there when a friend tried running his new
30L-1 on RTTY, by keeping the loading capacitor maxed.
After a few minutes, we smelled something burning. (I think
it was the 2W grid resistor R-28 overheating).
It spooked him about the 30L-1.
He later sold it (to me) and bought a Henry 3K.

Some 811A tubes are not suited for operation in horizontal mounting.
The plane of the filament structure should line up with the two
thick pins of the tube base for the tube to be OK in horizontal operation.

73,
Ed Knobloch