Help needed with Vauxhall Car Radio

[trsomian]

From what I remember, and it was a long time ago, my father's 1962 FB Victor was negative earth, obviously with a dynamo.

[cheerfulcharlie]

..And there you have it -proof positive

First pic from the Vauxhall 101 brochure for 1965 model year - second pic from the 1966 model year brochure.

[Radio Wrangler]

Mention of Current-Voltage Control (sometimes known as CVC or cut-out) in both cases means the generator was a dynamo. So they changed the electrical polarity but stayed with the dynamo. It would have made getting a radio a bit easier at the time and seem a bit more modern.

So the vehicle this radio is for is either a later one, negative earth from new, or else an earlier one which has been changed. But if it still has the dynamo, either way it could easily be changed to positive earth to suit the radio unless other electronics have been added, or are wanted to be added. The relay contacts in CVCs burned out after a while, and I don't think new ones have been made for quite some time, so I'd expect to find an alternator has been fitted. If so, that means staying with negative earth.

Looking ahead, with the reduction in choice going on in AM broadcasts it's reasonable to anticipate that the owner may wish to add some sort of local player, so staying with negative earth and changing the radio polarity may prove to be the less-limiting option.

I think rebuilding the set with silicon NPN devices could be an interesting way out of the quandary. There would need to be a bit of bias adjustment but it would give a period set to match the vehicle.

David

[Philips210]

Originally Posted by 'LIVEWIRE?'

Out of interest I've looked on the 'net for specifications of the Victor 101, and none that I've found states what the original polarity was. However, given that the Plessey radio in the OPs original enquiry is (a) Positive Earth, (b) branded 'Vauxhall', and (c) dates from the right era, I would expect 101s (and other early 60s Vauxhalls) to have been Positive Earth when new.

Hi.

I am fairly sure my late Dad's 1962 Vauxhall VX 490 (FB Victor) had the positive earth system with dynamo and regulator cutout. I think the 1965 FC Victor may have initially used positive earth then switching to negative earth. The 1967 FD Victor had negative earth.

Regards
Symon.

[Philips210]

Hi

Slightly OT but my neighbour's brother owns an old Morris 1000 which has a Pye TCR1000 car radio, the one with valves and single output transistor. Strangely, this early hybrid radio had the choice of both positive or negative earth arrangement by a simple rewire for the conversion. I would have thought that when this radio was built (late 1950's) then all British cars would have been positive earth. Maybe it was intended for the export market for countries using negative earth.

Regards
Symon

[AD360 Rob]

Morning all,
Well, I can confirm that the radio is indeed for the earlier FC 101 as I found a capacitor dated 1964. I suspect it was dealer fitted at the very start of 101 sales. My friend's car is I'm sure a 1965 model so will have been changed to negative earth. I'll speak to him over the next few days and find out what he's going to do. The radio is now fully repaired, the noisy OC82DM has been replaced with an AC128 which was a struggle to do without completely dismantling the radio. It actually works quite well but then again, most plessey products did in their unsophisticated way.

Thanks again for all the suggestions and research.

Rob