Quote:
Originally Posted by dtvmcdonald
What you wrote is what I more or less thought. It now boils down to
one question: is there RF on two of the three HV leads? If
so, it TRULY IS a chromatron, not just a larval Trinitron. If there
is no RF on any of the three leads, I would call it a larval Trinitron.
This question could be answered by a schematic or a scope with
its probe merely held a half inch or so from the CRT HV wires.
I believe the owner has a schematic ... it would be wonderful if
he could scan and post it! (the 7010U, not the 7010UA).
Doug McDonald
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I am the owner and unfortunately the service manual or schematic could not be found for the KV 7010U. I have searched extensively for them.
The service technician who worked on it said this:
“I suspect they are applying a DC voltage to the wire mesh and only using
it to focus the electron beams onto the correct phosphor stripes."
"The purity control on your set is probably varying the bias on the wire mesh.”
There is a label attached to the CRT bell identifying it as "Sony Chromatron Licensed under Patents of Paramount Picture Corporation"
The CRT tested very weak on all three beams (.1) and yet the KV 7010U still produces a very bright image due to the absence of a shadow mask or Aperture grill. I have screen shots. The promise of the Chromatron was to overcome the dim brightness of early RCA color, and no need to adjust for convergence, only one beam. The Sony KV 7010U shows very bright images, surprisenly bright for such low emissions.
Adding this: We compared the KV 7010U to the KV 7010UA. The KV 7010U has two HV instead of one, three connections of HV to the CRT instead of two, an electronic purity control instead of the standard control, the fine wire selection grill instead of the Aperature grill and the CRT bell is shaped diferently. Most of the circuit boards look the same.