26-12-2016, 02:03 AM
The schematic I have is for the 5170 and they can be tricky to find. The valves are ECH81 mixer, EC85 double triode and FM oscillator. The EBF89 double diode is reputed to run on low voltage and the EABC80 I know will run at 60 odd volts. The EL84 is the output valve. I'm not sure if the Mullard and German valves of the same names are identical. After some basic work I am now getting mind-boggling audio quality that beats anything modern. It is still only working on FM and the ECH81 triode anode is still dormant. My guess is a capaswitch problem as I got no voltage on the oscillator feed resistor but HT passes via a piano key knob (39 I think). Tonight I was weighing up the removal of the PCB and find the switches have tabs soldered to the boards at chassis potential.
Another thing I should add is this set really carries some voltage.
If I ease out the board I can change any wax capacitors and I can test the tracks. It is honestly a bit over my tlevel to be honest and is in the Philips range of repair. That includes the dial chord. However I can persevere and then share anything I discover. And let me repeat the sound on this is awesome. I have never heard such a quality of audio on any other radio to date.
Another thing I should add is this set really carries some voltage.
If I ease out the board I can change any wax capacitors and I can test the tracks. It is honestly a bit over my tlevel to be honest and is in the Philips range of repair. That includes the dial chord. However I can persevere and then share anything I discover. And let me repeat the sound on this is awesome. I have never heard such a quality of audio on any other radio to date.
