Successful Rebuilt of a 15GP22 at ETF

[Dave A]

Jerome,

I will be there Friday and looking for you to welcome you to our Delaware Valley Historic Radio Club monster meet at Kutztown. The place to be especially for you to take the congratulations on the 15GP22 effort.

To those who missed the ETF convention and have seen the photos, it was every bit as wonderful as you can imagine.

Pete and the two Steves did an amazing job cobbling this tube in a ETF donor cabinet with Pete's modified chassis. The first glow was a red flat-field from a generator albiet a bit blotchy. Then the fun began. Purity adjustments were odd. G1 adjustments were not responding properly. The distinct smell of ozone was in the air. That was a plate cap wiring fault and a spare was found but still continued to arc for the duration but did not affect the pix.

The chassis socket connection had to be turned past it's 55 year historic natural position. That gave the clue that the guns may have been mounted out of phase. Moving the RGB G1 connections proved that. The original circuit design was specific for the colors and moving them around to get a picture did not involve moving all the circuits. Close counted in this case and it was good enough for the first try. Convergence was left for a later day. The colors were there and there was no giant sucking sound of air rushing in. And the set ran like Secretariat for the duration.

The actual restored tube was something to see. The neck showed the usual glass welds and the original base was used even with it's missing chunks of base material and liberal amounts of adhesive showing. There were some splotches of contamination on the phosphor plate and given the train-wreck of a tube to use, it was not a deal-breaker. If you looked close at Judy Garland it could be seen but can be considered minor considering the success. And yes, clean the glass when you get yours rebuilt.

The infamous glass frit solution was interesting to see. It looked like someone smeared epoxy over the seams and was only used in this case on the bell side of the tube seam. But it was hard as a rock. Jerome can inform further as to how this will be done for future tubes.

There is still no known price for now. A work in progress that I was so happy to see happen right in front of me. Kudos to Jerome for his and RACS work on this and flying through volcanic ash to show us.

Find him at Kutztown and congratulate his effort,

Dave A