aeg: 1461; Bimby-Luxus: VHF-FM tuning

The EM85 magic eye works well on LW and MW. But on VHF-FM even though the radio picks up the National station (< 14km from Transmitter) and even the "in premises" weak Hospital station (7km)  very well, the magic eye doesn't move on VHF. Another radio on VHF the Eye closes entirely on the National station and fully open on the Hospital station.

Any ideas?

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Do you measure a DC voltage across the ratio electrolytic condensor C25 when receiving a FM station? Strong signals will generate 15...20 volts here. If so, please check the 2.7 Mohm resistor (W31) which connects pin 1 of the EM84 (not EM85) with pin 9 (g3) of the EF89. Most probably it's open.

Bernhard

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The W31 abd W32 are fine (2M7 and 1M5). But there was also a buzz on VHF-FM. So I looked at C17 and it was very corroded at + end. It and the ends for W21 & W35 (220k EABC anode load and 47K HT feed) stand off the PCB underneath. I didn't have a 2uF, but a same size 16uF 350V probably won't stress anything here.

The Magic Eye now overlaps on local VHF stations and buzz gone. C25 seems OK and the volts with no FM signal about -4V and about -26V with a strong station.

The Treble seems a little harsh with tone fully clockwise.

The wave switches were very crackly and are not really accessible, so I poured a little "white spirit" on the rear with radio chassis on its face and that has cured it.

Sadly there is no 230V or 240V taps, so I might have to fit a series 39 Ohm or 47 Ohm 5W resistor on input of transformer. Our Electricity seems to be usually a little bit more than 230V, sometimes as high as 235V.

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