Hi All
I have joined this group to see if I can pick your brains. I am, or was an electrician and in the past completed an industrial electronics course, most of which I have forgotten, as it was 30 years ago. Even then the module on valves consisted of the instructor holding one up and saying "this is a valve you will never have to work on one, now on to the next subject". I have always liked radios and even built a crystal set for my great nephew recently. I have a 1928 model A ford roadster which I built as a 30s-40s style mild hot rod. It still has the original 4 cylinder engine but with twin SU carbs and extractors etc. I have picked up a couple of ~1950s ferris portable car valve radios at swap meets with the idea of fitting one to the A Model. I got a capacitor kit of ebay and got one working. But no luck with the Ferris M106 It lights up and one valve glows but the remaining don't, I have replaced all the capacitors except the large electrolytics. And not even a crackle. I am not sure what to do next.
Any help would be appreciated.
Brendan

Hi there and welcome.

The Ferris M106 can be either operated from mains or old non existing batteries. This is not strictly a car radio (meaning it cant run off the car battery) and for battery operation needs a 9 volt "A" battery for the filaments + a 90 volt "B" battery for the HT. It has 6 valves: 1T4, 1R5, 1T4, 1S5, 3V4 & 6X4. I bet the only valve that is lighting up is the 6X4. The other valves are what as known as Battery Valves. The filaments of these valves joined together in series. If one of the valves filaments fails, the rest wont work either. That said, it is difficult to see if the filaments are lit even if they are working. The best way to see is in the dark. The reason the 6X4 still lights up is because it is independent of the of the other valves. If you require, I have scans of the manufacturers service manual for this radio. And feel free to ask for any advice on this forum. There are plenty of members here who are only too happy to help.

Cheers.

Hi Brendan,

There were a couple of guys on this Forum who collect/fix Ferris portable radios, so I hope they respond to you.
I have fixed a couple of Ferris radios, but thus far, only the early transistorised car radios. I have an early transistorised Ferris (M302) in my MGB.

Try to locate a circuit diagram for your radio as a starting point. Try the Kevin Chant website. Be aware of the safety issues with 240volt / battery radios.

Changing the caps is usually a good starting point, but now you will need to trace through the circuit with a multimeter, then an oscilloscope and possibly need a signal generator. Do you have this type of test equipment?

Cheers,
Ian

Thanks Guys
It is the 6X4 that is glowing and it does take a battery you are spot on, I am running it on 240 volts. I did have some difficulty finding an old style appliance plug, Had to call in a favour from our electrical wholesaler. I had not looked for a power in socket just assumed it would be there, so I guess I can fit my ferris 1949 model 74 (I think) to the Ford It looks better anyway. I would still like to get the 106 going if I can. The best I can do for test equipment is a multimeter. It seems I will have to pay $25 for a circuit. (and I am a cheapskate)
Brendan

Why pay for a circuit when you can have one for free.
Click on my profile and send me a email.

Cheers.