Here's a link from Terry Churchfield detailing the installation of the L7R kit

The Drake L7/L4 high voltage power supply upgrade is $100 +$10 shipping for the complete kit of parts.

PCB only is $25 +$6 shipping

I am out of stock right now.
Trying to get a fair price on a new run of pcbs.
It looks like the Drake L7R will have a fairly heafty price increase with the new pcb order. Price has yet to be set.

Drake L7R kit

Drake L7R Assemble pcb and test

Drake L7R PCB only

The Drake L7 and L4 HF amplifiers are getting old. The high voltage power supplies are now suffering from short diodes and leaky capacitors. To make matters worst, the axial capacitors Drake used in these old supplies are almost impossible to find today.

So,The Heathkit Shop came to the rescue with this single pcb upgrade.

This one double sided pcb with plated through holes is .093 inches thick.

All diodes are now rated at 1000 V at 3 amp. The capacitors are rated at 220 mFd at 450 V. They have a 105º temperature rating.

The bleeder resistors have been upgraded,too. Rated at 5 watts, they are flameproof as well.

This one pcb replaces BOTH of the original pcbs from Drake.

Detailed instructions are included

Warning!

The voltages inside the Drake L7/L4 supply and amplifer can and will kill you! This is not a project for the novice. If you do not have the skill or talent, then have someone else work on the project.