10-11-2016, 10:38 AM
Let's see if I can finally tough this one out. The TRF unit in my Marconi has always delivered insufficient video drive to the grid of the CRT. The video output from this unit never exceeds 10 volts P - P, it should be nearer 20 volts P - P.
There is no post detector video amplifier in this set, a high level video drive is supplied direct from the detector. The pre-detector TRF amplifier uses a special valve selected to handle the high level vision signals, Marconi MSP41.
It's just a waste of time fiddling about with unit inside the set, it'll be a much better procedure to take it out and carry out tests on the bench.
As you can see that stage of the task has already been done. Now to go fault finding.
Till Eulenspiegel.
There is no post detector video amplifier in this set, a high level video drive is supplied direct from the detector. The pre-detector TRF amplifier uses a special valve selected to handle the high level vision signals, Marconi MSP41.
It's just a waste of time fiddling about with unit inside the set, it'll be a much better procedure to take it out and carry out tests on the bench.
As you can see that stage of the task has already been done. Now to go fault finding.
Till Eulenspiegel.