Troubleshoot Phillips 483x at converter stage (ech4 tube) (Techniek Radio/TV)

door Maurice , Dordrecht, 17.06.2018, 14:46 (2140 dagen geleden) @ Radiosterk

Found indeed a schematic Philips 478ML that has ECH4.

Rare tube to be used in Philips receivers.

Ok, problem,

So
oscillator is working
Demodelation is working
Amp is working

Than look at the antenne circuit.
Antenne coil OK?
Antenne tuning Varicap OK? ,Not a shortage in plates or contacts?