26-09-2016, 08:38 PM
It is in fact the modulator that is causing all the problems. The modulator is the type that was made by W. Meier in I believe Germany.
I have no circuit information for this unit. Visible from the top side of the PCB there is a 45Mhz crystal controlled oscillator which employs a BF245 FET.
A 78M05 5 volt regulator IC. A few capacitors and resistors, two coils, one I assume is the 41.5Mhz oscillator for the sound carrier.
On the print side of the PCB is a single surface mounted IC of an unknown type, it is this device which is suspect.
The modulator is contained in a 70 X 70 X 30mm metal box.
Geordie McBoyne.
I have no circuit information for this unit. Visible from the top side of the PCB there is a 45Mhz crystal controlled oscillator which employs a BF245 FET.
A 78M05 5 volt regulator IC. A few capacitors and resistors, two coils, one I assume is the 41.5Mhz oscillator for the sound carrier.
On the print side of the PCB is a single surface mounted IC of an unknown type, it is this device which is suspect.
The modulator is contained in a 70 X 70 X 30mm metal box.
Geordie McBoyne.
