21-11-2018, 10:38 AM
(This post was last modified: 21-11-2018, 10:40 AM by Geordie McBoyne.)
Hi Jeffrey,
The EHT is derived from the line flyback. The line oscillator is of the Miller "transitron" type. Uses an SP61 pentode, a valve that in 1949 might have been considered old fashioned but it's likely there was thousands of these valves on surplus market, so why not use the things up? Also, the SP61 has all the right characteristics for the Miller oscillator. A Mullard PY31 is employed as the effifciency diode, the reclaimed energy is supplied to the cathode of the 6P28 output valve.
The mains derived EHT in the TSC113 uses a voltage doubler circuit to produce 10KV for the CRM151 CRT. Real scary stuff!
The frame oscillator employs a Mazda 6K25 thyratron. Particular regard to the frame sync circuit which employs an inductor (L21) to perform the sync integrator function.
Geordie McBoyne.
The EHT is derived from the line flyback. The line oscillator is of the Miller "transitron" type. Uses an SP61 pentode, a valve that in 1949 might have been considered old fashioned but it's likely there was thousands of these valves on surplus market, so why not use the things up? Also, the SP61 has all the right characteristics for the Miller oscillator. A Mullard PY31 is employed as the effifciency diode, the reclaimed energy is supplied to the cathode of the 6P28 output valve.
The mains derived EHT in the TSC113 uses a voltage doubler circuit to produce 10KV for the CRM151 CRT. Real scary stuff!
The frame oscillator employs a Mazda 6K25 thyratron. Particular regard to the frame sync circuit which employs an inductor (L21) to perform the sync integrator function.
Geordie McBoyne.
