Hi Guys, I am in South Africa and my 16 year old son is collecting old tube radios. His radios can be seen on this link:
http://frans-myradios.mypicgallery.com/mpg/Route.asp
He has now decided to start decapping and reparing the radios. The first problem: Some of the radios is 6 Volt and you don't get 6 volt batteries any more in South Africa. Is it very difficult to convert the 6 volt radios to 220 volt? I know that some of the vibrators doesn't work any more and also need to be replaced.
I have asked quotations for capacitors (kits) and tubes from a couple of suppliers and will order soon. Any advice will be appreciated. We are absolute rookies in this field.
Thank you
Frans

If you know the current and voltage specifications throughout the radio (what voltage is found at the rectifier, if a rectifier tube is used, or what voltage is found at the beginning of B+, the positive side of the high voltage system), you can replace the original vibrator transformer with an AC type transformer. This may be a bit beyond you, but if you know whether the radio uses a synchornous or non-synchronous vibrator, you can tell whether there will be a rectifier tube or not. Common rectifier tubes used in 6 volt battery radios are 0Z4, 6X5, 84/6Z4. There are others, of course, but I can't think of them right now.

You can try contacting www.tubesandmore.com and see if they have any 220 volt transformers. They normally carry 110 volt transformers, but they say that they do have some 220 volt transformers not listed.

What would really help would be for you to list the tube numbers used in the radio you wish to convert. That way someone on here can give you a rough idea of what kind of transformer to purchase. Extra information, such as the radio model number, high voltage specifications, high voltage current specifications (miliamperes), and such are real helpers.

I do not know if there are any Batteries Plus stores in South Africa. If there are, though, they carry 6 volt auto batteries for a very low price (the 600 ampere battery in my 1951 Chevrolet only cost $45.00). If you decide to use a 6 volt battery, you will need a 6 volt battery charger. Many companies sell 6/12 volt battery charger combinations. You simply flip a switch to select your voltage. You are probably better off, though, just converting the radio to 220 volts. This will be easier in the long run.

Thomas

Hi Thomas, Thank you for your response. The first radio that we would like to convert, is an Andrea. I am not sure about the model, but I emailed you a picture of label inside the box. The serial# is E20122. Do you perhaps have an idea what year this radio was made?

6 Volt batteries are really impossible to find in this country. This was my grandfather's radio and we used to play it on one half of a 12 V battery, but they dont make them with open terminals anymore.
Frans

Your picture did not come through in my e-mail. Andrea is listed in the resources section of this web site. Not sure if your model is listed or not. If you get the picture to go through, I can take a closer look.

Too bad they don't make open connected auto batteries anymore. We'll figure something out, though. At very least, if I am not able to come up with an AC transformer for you, I can see if I am able to get a hold on an order form for 6 volt auto batteries and battery chargers. They are extremely easy to come by here in the U.S. (Milwaukee, Wisconsin). Perhaps one can be shipped to you, though that would probably be incredibly expensive, and I'm not sure how easy it is to ship lead acid batteries. Well, we'll see....hopefully your picture will go through.

Thomas

At www.tubesandmore.com I came up with several transformers that will work on any standard AC 60 cycle household current. That will be an even bigger help than you already need, because if you move to a place with a different line voltage, you can change the transformer to that line voltage. The transformers have taps from about 110 volts to 240 volts in standard increments.

These are what I came up with:

P-T370FX with 275 volt high voltage winding @ 150 MA

P-T372BX with 300 volt high voltage winding @ 100 MA
....may be a little under powered for what you need....we'll see.

P-T372FX the same, but rated at 150 MA

P-T302AX the same, but rated at 200 MA

P-T372JX the same, but rated at 250 MA

P-T374BX with a 375 volt winding @ 175 MA

The last transformer is probably over-kill, as most vibrator radios do not go much above 300 volts in the high voltage section. All transformers have 6.3 volt filament windings, with ample power for most radios with a tube count between 5 and perhaps 8. All transformers also have a 5.0 volt winding for a rectifier. If a rectifier is already used in your radio, we can either use a 5.0 volt filamentary rectifier that is suited for the socket in place, or if none fit the socket used, we can substitute a different socket. If no rectifier is used, a tube socket can be put in place of the vibrator socket, and a rectifier may be used here. Once the model number is known for the radio, and a schematic has been secured, we can go from there.

Thomas

:Hi Guys, I am in South Africa and my 16 year old son is collecting old tube radios. His radios can be seen on this link:
:http://frans-myradios.mypicgallery.com/mpg/Route.asp
:He has now decided to start decapping and reparing the radios. The first problem: Some of the radios is 6 Volt and you don't get 6 volt batteries any more in South Africa. Is it very difficult to convert the 6 volt radios to 220 volt? I know that some of the vibrators doesn't work any more and also need to be replaced.
:I have asked quotations for capacitors (kits) and tubes from a couple of suppliers and will order soon. Any advice will be appreciated. We are absolute rookies in this field.
:Thank you
:Frans

:Hi Guys, I am in South Africa and my 16 year old son is collecting old tube radios. His radios can be seen on this link:
:http://frans-myradios.mypicgallery.com/mpg/Route.asp
:He has now decided to start decapping and reparing the radios. The first problem: Some of the radios is 6 Volt and you don't get 6 volt batteries any more in South Africa. Is it very difficult to convert the 6 volt radios to 220 volt? I know that some of the vibrators doesn't work any more and also need to be replaced.
:I have asked quotations for capacitors (kits) and tubes from a couple of suppliers and will order soon. Any advice will be appreciated. We are absolute rookies in this field.
:Thank you
:Frans

Hi There.
I'm also in South Africa and collect valve radios. I have restored a Philco and Zenith console radio which are battery operated. I made up mains to DC voltage supplies to operate these radios. In the case of the Zenith, the vibrator cct still works fine so just built a 230V AC to 6V DC supply. For the philco it was a bit more complicated as it required 2 Volt filament as well as other HT and bias DC voltages. Just another avenue to explore as the radios then remain original Regards: Des.

I tend to think that Des' suggestion is best. Build (or buy) a 6-V regulated (linear, not switching) power supply. You can Google for plans, but basically, here is the scheme: a step-down xfmr, 240-V to about 12-V ac; follwed by a bridge diode rectifier; then an electrolytic filter cap; a linear voltage regulator chip for 6-V dc (will require a heat sink); another filter cap; and you done. The whole shebang should fit in a cigar box.

Now, regarding the unavailability of 6-V lead-acid batteries in South Africa. In the U.S., American car manufacturers switched from 6-V batteries to 12-V batteries in the 1950s. I think, for some reason, farm tractors and possibly motorcycles continued with 6-V batteries for some time.

Of course, by now, there are few 6-V vehicles still on the road - most are in the scrap-heap or were converted to 12-V. But, 6-V batteries are still available, and antique car owners know where to get them.

Also, in the U.S., 6-V lead-acid batteries are still used in industrial and utility applications. For example, an electrical substation typically uses a bank of 6-V batteries for control power.

Smaller, 6-V sealed lead-acid batteries are readily available for alarm systems, portable equipment, etc. For example, see: http://www.batteriesamerica.com/newpage4.htm I see that Panasonic sells a 6-V, 12 amp-hour sealed battery. Used with a wall-wart charger, this should fit the ticket.