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 Autovox valve car radio
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 Return to top of page · Post #: 1 · Written at 3:16:19 PM on 19 February 2023.
Wodbore's Gravatar
 Location: Nowra, NSW
 Member since 19 February 2023
 Member #: 2539
 Postcount: 11

Unearthed this poor old Autovox car radio "barn find". Still legible number 1673, either 5 or 6 valve, 12 volt. Speaker box is separate to the main unit, and quite heavy. Any comments, suggestions welcome before I attempt any restoration. Have emailed 3 photos to Brad - hope he can attach.
Cheers
Wodbore

Autovox car valve radio
Autovox car valve radio
Autovox car valve radio


 
 Return to top of page · Post #: 2 · Written at 8:48:50 PM on 19 February 2023.
Brad's avatar
 Administrator
 Location: Naremburn, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 7301

Photos uploaded.

Welcome to the forums.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 3 · Written at 5:11:05 PM on 21 February 2023.
Wodbore's Gravatar
 Location: Nowra, NSW
 Member since 19 February 2023
 Member #: 2539
 Postcount: 11

Mmmm. Looks like a bit of work needed. Valves are 6V4 power supply in speaker box; 6M5, 6AE8, 6BD7, 6N8 in the main circuit. Two pics sent to Brad.
Cheers

Autovox car valve radio
Autovox car valve radio


 
 Return to top of page · Post #: 4 · Written at 1:49:23 PM on 22 February 2023.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6687

Valves are 6V4 ... 6M5, 6AE8, 6BD7, 6N8

Schematic here: https://www.kevinchant.com/uploads/7/1/0/8/7108231/autovox_five.pdf


 
 Return to top of page · Post #: 5 · Written at 9:47:20 PM on 22 February 2023.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5254

Definitely a fifties unit common valves, take photos of the innards before you touch anything.

As those were used with Kettering ignitions use 630V caps in the power supply. Exceptions the vibrator padder and probably any plate bypass cap, which are usually above 1KV.


 
 Return to top of page · Post #: 6 · Written at 11:38:38 PM on 22 February 2023.
Brad's avatar
 Administrator
 Location: Naremburn, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 7301

Photos uploaded to Post 3.


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A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 7 · Written at 3:07:26 AM on 23 February 2023.
Robbbert's avatar
 Location: Hill Top, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 2014

Looks like some work required there, given how filthy and rusty everything is.

The 6V4 is an early double-decker type.

Good luck, hopefully you can get it going again.


 
 Return to top of page · Post #: 8 · Written at 6:53:24 AM on 23 February 2023.
Fred Lever's Gravatar
 Location: Toongabbie, NSW
 Member since 19 November 2015
 Member #: 1828
 Postcount: 1250

Crikey Wodbore it looks like a back to bare metal restoration to me.
Or put it back in the skip!
Do not be daunted I have done exactly that to much bigger radios.
Looks like it has had water through it.
That means every part has to be removed, cleaned and either replaced or made fit for purpose again.
If it worked once it can be made to work again.
That is the sort of mission I enjoy.
Looking forward to hearing how you get on.
I'll stand on the side line and cheer!
Fred.


 
 Return to top of page · Post #: 9 · Written at 6:36:30 PM on 23 February 2023.
Wodbore's Gravatar
 Location: Nowra, NSW
 Member since 19 February 2023
 Member #: 2539
 Postcount: 11

Thanks for the encouragement guys; and for the schematic GTC. I can see this is going to be a long project, so my future posts might be a bit erratic.
Cheers


 
 Return to top of page · Post #: 10 · Written at 10:37:14 PM on 23 February 2023.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 2370

Yes big job.

Those Philips IF transformers I remember well. Our first 2 way radios in the business were Findlays, all valve but with a transistor inverter for the HT..

Did they ever need frequent service! They had those same Philips IFTs mounted in the same way, sandwiched between valves. They'd get hot, the wax would melt and they'd go off tune. I used to have a stack of them - I used them all up over a few years.

They don't take kindly to being pulled apart either. I once tried to fix a set of them by melting most of the wax out and replacing it with epoxy. A miserable failure!

Let's hope yours are OK, I doubt you'll find any replacements. Guys??

Note the slabs of asbestos (yes that's what it is!) on the sides of the one that's so sandwiched. Obviously Autovox had the same problem.

They should have been mounted at 90 degrees to their current position.

Seal those asbestos slabs with a few coats of varnish and it will be safe.

Might be wise to soak the vibrator transformer in varnish (Instant Estapol if you can get it).

That radio should be a hot performer when properly tuned up.


 
 Return to top of page · Post #: 11 · Written at 3:36:21 PM on 27 February 2023.
Wodbore's Gravatar
 Location: Nowra, NSW
 Member since 19 February 2023
 Member #: 2539
 Postcount: 11

So far things are not as bad as I thought. But I am sure Murphy is waiting in the corner of the shed.

Autovox car valve radio
Autovox car valve radio
Autovox car valve radio
Autovox car valve radio
Autovox car valve radio
Autovox car valve radio


 
 Return to top of page · Post #: 12 · Written at 9:01:26 PM on 27 February 2023.
Fred Lever's Gravatar
 Location: Toongabbie, NSW
 Member since 19 November 2015
 Member #: 1828
 Postcount: 1250

Yeah press on!

My experience is you have to be very very careful when dismantling a device like this.
The wires and insulations become brittle, just moving things can break things.
Like the transformer.
As Ian says and I have done, once removed you may have to re-sleeve some leads and yes after a day in the sun or in a low oven to make sure it is dry, a swim in the good old Estapol was exactly what I used to glue any loose windings solid with.
If not a swim, a spray of non acidic "lacquer" is also what I use from the Arts section at bunnings
Every piece that is to be used again will need cleaning, mineral turps will never hurt anything and will dissolve most crap.
Be very careful with anything more volatile on "plastics" or "Bakelite" pieces like sockets and coil bases.

You have to take each piece as it comes and go cautiously.
Kero also never hurt anything but needs to be flushed again with turps to get rid of the oils.
Rust also neds to be wire brushed or sanded away beware of where all the muck goes.
I think, you have to completely dismantle this one, and rebuild it like a "Kit" from Jaycar.
The metal needs a swim in rust stripper to get back to parent metal.
I have made my own strippers up and used plastic tubs as baths.
You may also bead blast or sand blast if you have the kit to do that.

Then there are any number of metal prep products and I used to have car paint suppliers mix a shade of top coat to suit.
You may also find just the right shade of colour at bunnings in the stock product.

Lots to thing about.

Keep at it.

Fred.


 
 Return to top of page · Post #: 13 · Written at 7:48:57 PM on 1 March 2023.
Brad's avatar
 Administrator
 Location: Naremburn, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 7301

Photos uploaded to Post 11.


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A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 14 · Written at 10:25:11 PM on 1 March 2023.
Robbbert's avatar
 Location: Hill Top, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 2014

I'm not sure how authentic you want to be with the power supply, but I doubt you'd want to have it running in your car.

Perhaps it might be better to ditch the vibrator and associated asbestos and large paper caps, and substitute a more conventional power supply to run off the mains. At least you have a 6V4 to get you started.


 
 Return to top of page · Post #: 15 · Written at 11:20:59 AM on 4 March 2023.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 2370

A mid 50's Morris Minor would be the ideal recipient!

That paper cap mounted on the 6V4 socket MUST be replaced with a suitable high current, high voltage type.

Like this:

https://au.element14.com/vishay/bfc237530822/cap-8200pf-1-6-kv-5-pp/dp/1166100?st=8.2nf%202kv%20high%20current%20cap


 
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