Hi crew, still laughing over some of the Australia Day comments. "Coopers" is still a home grown beer.
Thanks to our higher dollar we are tempted to look at
American radios....in my case 32 v ones.
Sadly the plugs are the same on radios with lower voltages,
therefore blown valves.
Can anyone help with tested RCA or Sylvania type 48 & 85 ?
TIA. Michael.

This as, I have pointed out, even on the American forum, is one of the many ramifications of plugging in a set to see if it works.

Sets should always be checked to see what they are and if they are in a fit condition to be powered. There is a 110V Midwest on my bench that has a two pin plug not disimilar to a DC plug. It was not turned on to see if it worked, and on examination, would have suffered damage if I did that.

In the same light a Breville in the last month with a dead short in it's converter, on the heater line and a couple of wires that the insulation fell off.

Not the only sets like that in the last year and I often need to repair extra damage caused by powering equipment that was not in a fit state to be powered.

It is interesting to note that in the dis-interest of safety 110V 3 pin plugs are not easy to come by. I prefer the Three pin 110V plug on 110V sets, as it cannot be plugged into an Australian 240V plug accidently.

If that is an American set you may have to try tubesandmore.com?

Marc

Thanks Marc,
yes an American set where the 32v plug has the same 2 pins as the 110v one. Damaged before I got involved.
Thanks for the tube/ valve source. M.

I would go over that set with a toothpick & comb. and if possible test all the valves, even if is the most basic tester, clearly the heaters will all be suspect.

I assume that is a vibrator set? That whole circuit including the vibrator & transformer will need checking if it is.

Unfortunately, this has all the hallmarks of being a non-restorer, or expensive.

Probably won't matter about electrolytics & papers as they were likely cactus without the help.

Marc

Hi Marc, its the common Delco 3201,
valves are 6D6 6A7 6D6 85 48 48.
No vibrator...i believe the 48 valves run on 30v.

Interesting: Did have a quick look for a circuit, did not see one.

I have never seen 6D6, 6A7, run that low in voltage on the plates, not withstanding UX-201-A is one that would work that low.

Along the same lines as before, that being hit with 110V, is not good.

Marc

G'day Michael,

First of all I would check the field winding on the dynamic speaker and if open, would utter some strong words, get a bottle of strong alcohol and sit down and drink the lot.

And if I wished to torture myself even more, I'd then check the audio coupling and output transformers.

Do you require a schematic?

Cheers, Graham...

Hi Graham,
thanks for reply...seems I should be taking advice before a purchase...not after !
Some of us learn the hard way...
Got a copy of schematic from 'Nostalgic Air' Cheers Michael.

May pay to post a link to the circuit so that we can get an idea of what may be cooked. With a bit of luck it may have had an electrolytic on the HT & that took load.

I repaired an Astor RK over a year ago that I believe was hit by lightning, that merely wiped out every cap & resistor in it.. All the valves & transformers survived and I did insulation test the mains transformer.

Should hopefully go for years with all those new bits.

Marc

G'day All,

Marc, one source of the schematic is http://www.nostalgiaair.org/Resources/381/M0022381.htm.

Michael, my quip about the field coil was to point out that the field was not wired as a filter choke as in a normal AC radio but sits across the 32 volts to generate the magnetic field. If the winding failed one could replace the speaker with a PM type and reduce the current draw on the 32V.

Please keep us informed on progress.


Cheers, Graham...

Looked at circuit.... treat as struck by lightning.. ie you are going to have to check everything.

Nasty

Marc

Ok thanks Marc....looks like a long road ! M.

The most "at risk" is the plate side of the transformers, the valves, & the field.

The resistors & caps are the easiest & cheapest & as I said most of the paper caps will leak any way.

Unfortunately you get sets like that. I hevecompleted repacing virtually every cap & lots of resistors in an American Midwest they have parts inside IF cans as well as obvious ones. 16 Valves & several bands do use a lot of caps & resistors.

Marc