Radiomobile 108S Alignment Issues - UK Vintage Radio Repair and Restoration Discussion Forum

Magical · 23rd Feb 2021, 3:07 am

Hello all,

I’m trying to finish a repair on a Radiomobile 108SR N/P, which is positive earth. The owner unfortunately accidentally brushed a positive crocodile clip against the power terminal a “blew” his set. He said the radio was working fine before. On opening up the set and looking at the output amp section I found a blown track, which I repaired and I replaced two BC139 transistors. The output amp works fine and the 8 track plays well.

The problem I have is with the radio. I can get no output from the normal aerial. If I touch the component tails sticking through the circuit board just by the waveband selector I can pick up very faint signals.

Using a signal generator I can tune to get a strong output at 1600Hz. I can also tune to get a strong output on the IF at 470Hz. The problem is tuning for each of these scenarios upsets the other. Can anyone give me a pointer please?

Cheers,

Magical · 23rd Feb 2021, 6:26 am

Sorry, quick correction....1600kHz and 470kHz...

23rd Feb 2021, 3:07 am	#1
Magical Triode Join Date: Jun 2020 Location: Stoke-on-Trent, Staffordshire, UK. Posts: 33	Radiomobile 108S Alignment Issues Hello all, I’m trying to finish a repair on a Radiomobile 108SR N/P, which is positive earth. The owner unfortunately accidentally brushed a positive crocodile clip against the power terminal a “blew” his set. He said the radio was working fine before. On opening up the set and looking at the output amp section I found a blown track, which I repaired and I replaced two BC139 transistors. The output amp works fine and the 8 track plays well. The problem I have is with the radio. I can get no output from the normal aerial. If I touch the component tails sticking through the circuit board just by the waveband selector I can pick up very faint signals. Using a signal generator I can tune to get a strong output at 1600Hz. I can also tune to get a strong output on the IF at 470Hz. The problem is tuning for each of these scenarios upsets the other. Can anyone give me a pointer please? Cheers,

23rd Feb 2021, 6:26 am	#2
Magical Triode Join Date: Jun 2020 Location: Stoke-on-Trent, Staffordshire, UK. Posts: 33	Re: Radiomobile 108S Alignment Issues Sorry, quick correction....1600kHz and 470kHz...