Grundig Radiogram Mandello 3WE/FM (Algemeen)

door Pandu Rajan , 29-02-2024, 08:27 (272 dagen geleden)

Dear Friends
The radio of the above radio gram has come to me for repair. The radio chasis is CS155 WE/f. In the original version the chasis CS155 it has LW,MW,SW and FM bands but this chasis has MW, 2 SW and FM band. Some body has removed all the components of the power amplifier and I took it up as a challenge to restore the set. The module 7210-309 was also removed and luckily I have been able to get it back. The tracks of this module were damaged and I have repaired the same. Some of the tracks of the main PCB are also damaged and the same is to be repaired. The other components including the power transistors AD161/162 I am arranging locally. Now before I start The actual restoration I need some clarifications which are as follows:

1. On the FM antenna side the PCB 7301-081 is damaged. One small portion is missing. It is a spiral track. How I should I repair this?

2. The coil+ capacitor (C102 and coil 9218-022.01)in series with the gang condenser antenna section and (C103 and same coil in series with the oscillator section of the gang condenser) are missing. What is the solution?

3. I think two thermistors are fitted on the heat sink of AD161/162 - R66 and R67. which are missing.

4. Coils 9218-152.03 connected to the Emitter of the power transistors of both channels are missing?

5 Preset pot R53 is missing which i will be able to arrange.

6. Both the diodes 0310 are missing. What should be the current rating of these diodes?

I have marked all the above with red circle on the schematic which I am attaching.

One last help- I have marked at two places with black circle. What are these? are they measuring points? and also what is the use of the coil 9217-019 connected in series with a zenner diode 9731 I presume?

I shall be thankful if experts can guide me on the above points

Regards
P.Rajan