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Brought the chassis in the house tonight to see if it would make a picture.
First I tried the CRT from my first 2500, the one that I junked, I thought it might be good but it turned out to be nearly dead! It wouldn't even make a visible raster in a normally lit room.
I reattached the base to tube number 2, the one that came with this set, hooked it up and turned on the TV and the DVD player, got a raster with lots of static and lines but no picture.
I wasn't sure if I had a matched pair of channel 4 tuner strips since the numbers were pretty messed up so I robbed a pair out of my spare chassis, this time when I turned it on I could see it had a picture but the horiz was flopped over and wouldn't lock in with the hold control.
Apparently the control is the only method of adjusting the Horiz, there is no frequency coil that I can find so something must be out of tolerance in the circuit. I grabbed a jumper and a resistor and hooked it across the resistor that's in series with the Horiz control and the picture popped in!
I also discovered the Kine Bias control, turning this up along with having a signal and this old CRT has a tremendous amount of brightness, despite the dark phosphors, it should be perfectly usable so I can save the new tube for later.
Here are some pictures, it's really hard to take a good picture of the screen because of the sharp contrast ratio, also the brown band is a camera artifact and not visible with the eye.
Obviously it still needs a little work to fix the horiz and get the picture looking it's best, there are probably some resistors out of spec here and there but I'm pretty happy with these early results.
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