diode gun plumbicon versus standard

[austvarchive]

I would like to know, are the requirements for a diode gun plumbicon any different to that of a standard plumbicon?

I want to refit a tk76 which took a standard plumbicon (XQ1427)with some later diode gun versions (XQ2427), can anyone tell me if this can be done without issues?

James

[old_tv_nut]

My GUESS is that the only electrical issues would be obtaining the correct gun voltages, but that the target voltage and signal currents would be the same. No idea if there are any mechanical incompatibilities.

Hope someone here really KNOWS.

[Dave A]

Everything you ever wanted to know about plumbicons including diode guns (page 7). Courtesy of Naragansett Imaging. They stopped mfg of tubes but still carry some stock. They might be nice guys and answer your sub question.

http://www.nimaging.com/products/no_...0Operation.pdf

And this is lifted from an non-working website found on Google;

"Diode-gun Plumbicon tube has modulator grid which is operated with positive voltage w.r.t. the cathode, as in a vacuum-tube diode."

[J Ballard]

Hello-

I've only had experience with 30mm diode guns and would think carefully about the conversion. True, the resolution is higher, but you may experience a phenomenum known as "stern waving" especially in high contrast scences.

I once saw a dancing actor dressed in a tux (high contrast scene)appearing on a modified RCA camera converted to diode guns. Sharp pictures, but the strong lag resembled a digital decay effect.

My recollection is that the beam spot size is too fine for the line structure (in this case 480i). You may have different luck with 18mm tubes.

The best advice on pickup tubes came from Bob Neuhauser of RCA-you have to design the electron optics to the scanning standard used. Good advice.

Let the group know how the conversion works out.

JB