[Collins] 572B and the 30L1

[w9hak]

For all those 30L1 drivers out there...............first timers and not 
so first timers............

I just installed the 572B in my 30L1. They tune the same as the 811's. I 
was able to install them via the top cover after unplugging the amp. The 
Chinese 572B's have a slightly longer guide pin and may not pass through 
the chassis hole. Enter the Dremel tool, just nip off  the amount 
required to get the tube to pass thought the chassis opening.

The top inside 572 just fits after shortening the pin. The top of the 
tube touches the loading capacitor, and you can't tip the tube enough to 
get the pin through the opening. While you are in there, lubricate the 
fan wicks and blow out the house dust. That two thousand volts is great 
at collecting dust particles.

Smith Bradford
W9HAK