The Ford Barn

Red98 · 03-03-2019, 10:38 PM

If you wish to spend $600 to upgrade your 6V radio to 12V, go right ahead.

Here is how I spent about $65 to convert my radio to 12V. And the conversion can be reversed should a future owner so desire.

First, buy a 6V NEGATIVE GROUND solid state vibrator.
Second you know about changing 6v bulbs to 12v, well same with vacuum tubes which have a bulb like heater 'filament' operating at battery voltage.

Learn the numbers (and location) of each of the radios six to eight vacuum tube which will be something like 6V6 and 6SK7. Vacuum tube filament voltage, (that '6' number before the alpha-letter) needs to be changed to a '12' to work on the car's 12 volt battery. A 12V6 has the same innards as a 6V6 except for the filament. Again note those first numbers.

You may need to find a schematic with tube locations as simply removing a tube may not show it's number as they fade. Numbers are generally stamped on the somewhere on the glass but they do get rubbed off. I poked around eBay to find schematic of my radio for about ten dollars. But a paper label is often pasted inside the radio. One way or the other get a list of vacuum tubes and tube locations.

Next, at eBay, do a search for two of the 12v tubes you need. Like "12V6 12SK7". Once you get listings for those tubes it is quite likely the seller will also have all the tubes you need. Get a quote from each seller who appears worthy. I found a seller who quoted me $19 +$4 s/h for the 8 tubes I needed. He also claimed to have tested them OK.

Next, if you aren't comfortable soldering you may need help from a friend. Tubes operate around 200 volts, this voltage is known as B+. If you simply apply 12v to the vibrator, B+ voltage generated will be too high. By applying 6V to the vibrator instead of 12V, the B+ stay close to normal. This is done by installing a LM7808 voltage regulator. Eight voltas is closer to normal than 6 but if you wish to use a LM7806 regulator, fine. Use a 0.1ufd capacitor on input and output of the regulator. The regulator circuit is placed between the switched radio input and the center tap of the B+ transformer. The rectifier tube in this circuit has it's filament on pins 2 and 7. Either pin 2 or 7 is grounded, the other is connected to the transformer center tap. The regulator semiconductor needs it's heat to be removed so it needs to be bolted to the radio's case. Regulator middle pin is ground. Fingers up, the right pin is the input and the left is the output.

I expect questions as everyone's knowledge and experience around the garage varies. But know the conversion isn't that difficult. FWIW, my new current draw for the radio has gone from about 5A to 2A. (Ever have music on the radio for your girl while the battery went dead?)

I was surprised how inexpensive the tubes were and how expensive the vibrators have gotten. But I feel good about having a normal 12V slow warmup radio.

BTW my antenna became broken off so I bought one of those motorized antennas for about $12. While the radio is open, I will add a cable/plug to the radio's switched voltage soas the antenna will arise with the radio turned on and go down flush with the radio off.

RalphM · 03-03-2019, 11:19 PM

That’s pretty slick! I’ve got a complete dash, radio included, from a 55 Ford hanging in my gagage. I’ve always thought it would be neat to hook it up to power and be able to play it.
( my first car was a 55)

34PKUP · 03-03-2019, 11:46 PM

The last time I did a 12 volt conversion, I just used a 15 amp voltage reducer for the radio. It worked perfectly for several years and was still working years after I sold the car. What did I do wrong?

Red98 · 03-04-2019, 12:13 AM

Wrong is not for me to say. As an electrical engineer, I prefer the elegant solution and chose to share it.

Frankly, I've not seen an inexpensive 'voltage reducer'. Why did you choose a 15 amp unit when the radio draws 5 amps?

FYI, your radio obviously has a mechanical vibrator. Since those are no longer available, if and when you need to replace it with a solid state vibrator, pay attention to its polarity.

Just thought to add that a previous owner of my radio had it serviced before coming to my ownership. The capacitors have been replaced with newer ones. I have to assume it originally had wax caps which started oozing.

flatheadmurre · 03-04-2019, 01:32 AM

Have you measure the anode voltage in it after doing the swap ??
Even if you now have the correct heater voltage and and a vibrator working...the turn ratio of the transformer after the vibrator is still the same so anode voltage may end up higher then the tubes spec...or the tubelife will be short.
Can probably be fixed by raising a resistor value in the filtering of the anode voltage if to high.

34PKUP · 03-04-2019, 03:19 AM

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Quote:

Originally Posted by Red98

Wrong is not for me to say. As an electrical engineer, I prefer the elegant solution and chose to share it.

Frankly, I've not seen an inexpensive 'voltage reducer'. Why did you choose a 15 amp unit when the radio draws 5 amps?

FYI, your radio obviously has a mechanical vibrator. Since those are no longer available, if and when you need to replace it with a solid state vibrator, pay attention to its polarity.

Just thought to add that a previous owner of my radio had it serviced before coming to my ownership. The capacitors have been replaced with newer ones. I have to assume it originally had wax caps which started oozing.

Sorry but I am not an "electrical engineer" so I chose a 'reducer' that was closest to the value of the factory installed '14 amp' radio fuse.
Should I have chosen a reducer of less value to make it work better?

flatheadmurre · 03-04-2019, 03:49 AM

Bigger is never wrong for performance...just cuts a bigger hole in the wallet...and if the radio takes 5A at idle warmed up i suspect the current draw at startup to be in that range...
With the switchmode coonverters being dirtcheap today it´s probably a cost effecient solution...

Red98 · 03-04-2019, 04:26 PM

Quote:

Originally Posted by flatheadmurre

Have you measure the anode voltage in it after doing the swap ??
Even if you now have the correct heater voltage and and a vibrator working...the turn ratio of the transformer after the vibrator is still the same so anode voltage may end up higher then the tubes spec...or the tubelife will be short.

I measured the B+ BEFORE and AFTER the conversion to insure my choice of voltage reducer to the vibrator circuit was valid. Were it too high I would changed to a LM7806. Incidentally max B+ is about double the working voltage for the tubes in my radio. I worry more about the transformer life than the tube life should the voltage be excessive.

richard crow · 03-04-2019, 06:10 PM

by a power inverter pgpl-hc from custom autosound your done in 10 min. 714 535-1091 converts 6v pos ground to 12v neg bin using one for years

34pickup · 03-04-2019, 08:19 PM

I knew I should not have opened this thread....

Tinker · 03-04-2019, 10:59 PM

I just had a "how to" conversation with my brother-in-law a few weeks back (a mechanical engineer, that asked his friend a electric engineer) about making a device to convert 12v batteries to 6v, pre-cab/harness.

Running a 12v in a 6v car, reducing voltage at the battery feed to everything (right off the battery). Shouldn't be that bad, maybe heat from the resistor. (all a runtz is).

Please "amp" guys leave this alone.

One thought was charging. How to. Starter can take 12v. but you need to return 12v to the battery.

.

cas3 · 03-05-2019, 01:37 AM

im surprised at all the fuss here. the op was kind enough to lay out a professional description of a how to, and folks want to buck! there has been inverters around for ever, but they take power from the already weak charging system. plus, like most crap these days, they fail, and they are not cheap. i am on my 3rd 110 converter thing to charge the laptop from the cig lighter, they seem to last about 20 hours, the last one i bought the extra warranty, and it got replaced, but why should i have to? i'd be happy to spend more for one made to last...where ever its made. so same deal on radios, build the original as told, or keep buying more chinese voltage gadgets. thanks for taking the effort to post the info

Red98 · 03-05-2019, 08:01 AM

Quote:

Originally Posted by Tinker

...Running a 12v in a 6v car,...

I've ordered a performance flathead, otherwise I'd keep the car 6v. But high compression requires more starter torque. A performance ignition requires 12v. And a cooling fan requires a beefy charging circuit. The radio is temporary because I know how, the cost is small, and it fills cold winter hours with satisfaction.

For me a 12v conversion is changing bulbs but I want to create a totally 12v car with ALL 12v components. My starter has a 12v field, gauges have a Mustang regulator, the heater fan has a 12v motor and charging is a shiny chrome 90A alternator.

I've periodically posted my changes for those who appreciate alternatives. I'm not intimidated by those who settle for a simpler conversion nor will I ridicule them for doing it their way. A hobby should be fun and rewarding.

FYI 2020 phase II will be a custom power panel w/ 5 relays (including OD & headlights), 10 aircraft circuit breakers and a harness of aircraft wire connected to the car via Molex MPX connectors. The Optima battery is going into the trunk using 4/0 cables from BatteryCablesUSA to better show off the engine. If I can evade a wheel chair the fun will never end.

Thanks ca3 for you kindness.

51 MERC-CT · 03-05-2019, 12:20 PM

Quote:

Originally Posted by Red98

BTW my antenna became broken off so I bought one of those motorized antennas for about $12. While the radio is open, I will add a cable/plug to the radio's switched voltage soas the antenna will arise with the radio turned on and go down flush with the radio off.

Interesting way to convert a radio.
Did mine 20 years ago using a J.C.Whitney ceramic block Volt-a-drop that they used to sell.
It worked well until I realized that all I had was an AM radio on which all I could get was talk shows, Latin music and Polka music on Sunday.
That's when I decided to up grade to AM/FM stereo with an aux. input.
I also installed a flush mount antenna controlled by a separate switch to control it (this keeps it down when using the aux. function.)

Tinker · 03-06-2019, 01:59 AM

Quote:

Originally Posted by Red98

I've ordered a performance flathead, otherwise I'd keep the car 6v. But high compression requires more starter torque. A performance ignition requires 12v. And a cooling fan requires a beefy charging circuit. The radio is temporary because I know how, the cost is small, and it fills cold winter hours with satisfaction.

For me a 12v conversion is changing bulbs but I want to create a totally 12v car with ALL 12v components. My starter has a 12v field, gauges have a Mustang regulator, the heater fan has a 12v motor and charging is a shiny chrome 90A alternator.

I've periodically posted my changes for those who appreciate alternatives. I'm not intimidated by those who settle for a simpler conversion nor will I ridicule them for doing it their way. A hobby should be fun and rewarding.

FYI 2020 phase II will be a custom power panel w/ 5 relays (including OD & headlights), 10 aircraft circuit breakers and a harness of aircraft wire connected to the car via Molex MPX connectors. The Optima battery is going into the trunk using 4/0 cables from BatteryCablesUSA to better show off the engine. If I can evade a wheel chair the fun will never end.

Thanks ca3 for you kindness.

I wasn't bad mouthing you or what you did, i never mentioned it actually. My comment was just a thought/idea on 12v batteries on a 6v car. Sorry.

flatheadmurre · 03-06-2019, 09:45 AM

Fixing stuff is like eating icecream...we all like different flavours...no right no wrong.
And good is that or my favourite flavour would always be gone...

Robz51 · 03-07-2019, 12:29 PM

I, for one. Like and appreciate the post very much. Please keep 'em coming!
Rob

Pete · 03-07-2019, 04:45 PM

"10 aircraft circuit breakers and a harness of aircraft wire"

I thought I would never run into someone that does it like I do....I love that teflon covered wire.

This thread reminds me of a song John Conley had, "Stuff That Works".

Marv · 03-07-2019, 04:46 PM

Quote:

Originally Posted by 34PKUP

The last time I did a 12 volt conversion, I just used a 15 amp voltage reducer for the radio. It worked perfectly for several years and was still working years after I sold the car. What did I do wrong?

That is the way I done mine and it worked for years. Maybe still working. I do not remember amp of the reducer.

Mike51Merc · 03-08-2019, 07:57 AM

I thought this was an "asking" post and pleased to find it is a "telling" post.

Well done.

03-03-2019, 10:38 PM	#1
Red98 Member Join Date: Nov 2018 Posts: 60	Converting 6V radio to 12V inexpensively without rruining the radio If you wish to spend $600 to upgrade your 6V radio to 12V, go right ahead. Here is how I spent about $65 to convert my radio to 12V. And the conversion can be reversed should a future owner so desire. First, buy a 6V NEGATIVE GROUND solid state vibrator. Second you know about changing 6v bulbs to 12v, well same with vacuum tubes which have a bulb like heater 'filament' operating at battery voltage. Learn the numbers (and location) of each of the radios six to eight vacuum tube which will be something like 6V6 and 6SK7. Vacuum tube filament voltage, (that '6' number before the alpha-letter) needs to be changed to a '12' to work on the car's 12 volt battery. A 12V6 has the same innards as a 6V6 except for the filament. Again note those first numbers. You may need to find a schematic with tube locations as simply removing a tube may not show it's number as they fade. Numbers are generally stamped on the somewhere on the glass but they do get rubbed off. I poked around eBay to find schematic of my radio for about ten dollars. But a paper label is often pasted inside the radio. One way or the other get a list of vacuum tubes and tube locations. Next, at eBay, do a search for two of the 12v tubes you need. Like "12V6 12SK7". Once you get listings for those tubes it is quite likely the seller will also have all the tubes you need. Get a quote from each seller who appears worthy. I found a seller who quoted me $19 +$4 s/h for the 8 tubes I needed. He also claimed to have tested them OK. Next, if you aren't comfortable soldering you may need help from a friend. Tubes operate around 200 volts, this voltage is known as B+. If you simply apply 12v to the vibrator, B+ voltage generated will be too high. By applying 6V to the vibrator instead of 12V, the B+ stay close to normal. This is done by installing a LM7808 voltage regulator. Eight voltas is closer to normal than 6 but if you wish to use a LM7806 regulator, fine. Use a 0.1ufd capacitor on input and output of the regulator. The regulator circuit is placed between the switched radio input and the center tap of the B+ transformer. The rectifier tube in this circuit has it's filament on pins 2 and 7. Either pin 2 or 7 is grounded, the other is connected to the transformer center tap. The regulator semiconductor needs it's heat to be removed so it needs to be bolted to the radio's case. Regulator middle pin is ground. Fingers up, the right pin is the input and the left is the output. I expect questions as everyone's knowledge and experience around the garage varies. But know the conversion isn't that difficult. FWIW, my new current draw for the radio has gone from about 5A to 2A. (Ever have music on the radio for your girl while the battery went dead?) I was surprised how inexpensive the tubes were and how expensive the vibrators have gotten. But I feel good about having a normal 12V slow warmup radio. BTW my antenna became broken off so I bought one of those motorized antennas for about $12. While the radio is open, I will add a cable/plug to the radio's switched voltage soas the antenna will arise with the radio turned on and go down flush with the radio off. Last edited by Red98; 03-03-2019 at 11:44 PM.

03-03-2019, 11:19 PM	#2
RalphM Senior Member Join Date: Nov 2015 Location: North Pole, Alaska Posts: 2,651	Re: Converting 6V radio to 12V inexpensively without rruining the radio That’s pretty slick! I’ve got a complete dash, radio included, from a 55 Ford hanging in my gagage. I’ve always thought it would be neat to hook it up to power and be able to play it. ( my first car was a 55)

03-03-2019, 11:46 PM	#3
34PKUP Senior Member Join Date: Feb 2011 Posts: 794	Re: Converting 6V radio to 12V inexpensively without rruining the radio The last time I did a 12 volt conversion, I just used a 15 amp voltage reducer for the radio. It worked perfectly for several years and was still working years after I sold the car. What did I do wrong?

03-04-2019, 12:13 AM	#4
Red98 Member Join Date: Nov 2018 Posts: 60	Re: Converting 6V radio to 12V inexpensively without rruining the radio Wrong is not for me to say. As an electrical engineer, I prefer the elegant solution and chose to share it. Frankly, I've not seen an inexpensive 'voltage reducer'. Why did you choose a 15 amp unit when the radio draws 5 amps? FYI, your radio obviously has a mechanical vibrator. Since those are no longer available, if and when you need to replace it with a solid state vibrator, pay attention to its polarity. Just thought to add that a previous owner of my radio had it serviced before coming to my ownership. The capacitors have been replaced with newer ones. I have to assume it originally had wax caps which started oozing.

03-04-2019, 01:32 AM	#5
flatheadmurre Senior Member Join Date: Apr 2015 Location: Sweden Posts: 3,045	Re: Converting 6V radio to 12V inexpensively without rruining the radio Have you measure the anode voltage in it after doing the swap ?? Even if you now have the correct heater voltage and and a vibrator working...the turn ratio of the transformer after the vibrator is still the same so anode voltage may end up higher then the tubes spec...or the tubelife will be short. Can probably be fixed by raising a resistor value in the filtering of the anode voltage if to high.

03-04-2019, 03:49 AM	#7
flatheadmurre Senior Member Join Date: Apr 2015 Location: Sweden Posts: 3,045	Re: Converting 6V radio to 12V inexpensively without rruining the radio Bigger is never wrong for performance...just cuts a bigger hole in the wallet...and if the radio takes 5A at idle warmed up i suspect the current draw at startup to be in that range... With the switchmode coonverters being dirtcheap today it´s probably a cost effecient solution...

03-04-2019, 06:10 PM	#9
richard crow Senior Member Join Date: May 2010 Posts: 1,769	Re: Converting 6V radio to 12V inexpensively without rruining the radio by a power inverter pgpl-hc from custom autosound your done in 10 min. 714 535-1091 converts 6v pos ground to 12v neg bin using one for years

03-04-2019, 10:59 PM	#11
Tinker Senior Member Join Date: May 2010 Location: MN Posts: 7,053	Re: Converting 6V radio to 12V inexpensively without rruining the radio I just had a "how to" conversation with my brother-in-law a few weeks back (a mechanical engineer, that asked his friend a electric engineer) about making a device to convert 12v batteries to 6v, pre-cab/harness. Running a 12v in a 6v car, reducing voltage at the battery feed to everything (right off the battery). Shouldn't be that bad, maybe heat from the resistor. (all a runtz is). Please "amp" guys leave this alone. One thought was charging. How to. Starter can take 12v. but you need to return 12v to the battery. . Last edited by Tinker; 03-05-2019 at 12:21 AM.

03-05-2019, 01:37 AM	#12
cas3 Senior Member Join Date: Jan 2011 Location: sw minnesota Posts: 4,568	Re: Converting 6V radio to 12V inexpensively without rruining the radio im surprised at all the fuss here. the op was kind enough to lay out a professional description of a how to, and folks want to buck! there has been inverters around for ever, but they take power from the already weak charging system. plus, like most crap these days, they fail, and they are not cheap. i am on my 3rd 110 converter thing to charge the laptop from the cig lighter, they seem to last about 20 hours, the last one i bought the extra warranty, and it got replaced, but why should i have to? i'd be happy to spend more for one made to last...where ever its made. so same deal on radios, build the original as told, or keep buying more chinese voltage gadgets. thanks for taking the effort to post the info

03-06-2019, 09:45 AM	#16
flatheadmurre Senior Member Join Date: Apr 2015 Location: Sweden Posts: 3,045	Re: Converting 6V radio to 12V inexpensively without rruining the radio Fixing stuff is like eating icecream...we all like different flavours...no right no wrong. And good is that or my favourite flavour would always be gone...

03-07-2019, 12:29 PM	#17
Robz51 Senior Member Join Date: May 2010 Location: Rogers, AR, USA Posts: 141	Re: Converting 6V radio to 12V inexpensively without rruining the radio I, for one. Like and appreciate the post very much. Please keep 'em coming! Rob

03-07-2019, 04:45 PM	#18
Pete Senior Member Join Date: May 2010 Location: Wa. Posts: 5,407	Re: Converting 6V radio to 12V inexpensively without rruining the radio "10 aircraft circuit breakers and a harness of aircraft wire" I thought I would never run into someone that does it like I do....I love that teflon covered wire. This thread reminds me of a song John Conley had, "Stuff That Works".

03-08-2019, 07:57 AM	#20
Mike51Merc Senior Member Join Date: May 2010 Location: Northeast Pennsylvania Posts: 1,582	Re: Converting 6V radio to 12V inexpensively without rruining the radio I thought this was an "asking" post and pleased to find it is a "telling" post. Well done.