Hello all, I have read the previous thread about this topic, but I wanted to create a new one since I am kind of a novice at electronics building. First off, I'd rather buy one than build it, so if anyone have one please let me know. Lastly, if I do need to build it, can anyone offer a step by step/ a schematic or parts list or something? I'm a little lost when it comes to trying to figure out how to modify a modern automotive inverter.

Schematic sent.

Power Supply circuit is shown on left side of diagram.

Dennis

Thank you so much, now my next question is:

Are the parts in the power supply easy to get? I know things like capacitors and resistors are a dime a dozen, my the specific parts like the rectifier or transformer, how do I go about getting those?

Most of us in the vintage radio hobby purchase our parts online.....unless that is, you happen to be fortunate enough to live near a good electronics supply house.

Here's a list of links of dealers that I like to deal with.

You'll have to browse their sites and do some searching to find the parts you need. Some have a minimum order......some do not.

You mentioned that you are a novice to electronics. Having no idea of your actual level of expertise I can only recommend that you take it slow and read up on electronics theory, radio theory, and vintage radio repair before you get in too deep.

This book, available on Amazon.com is a very good one to increase your knowledge:

You can also click on the "LINKS" option at the top of this page for a nice list of support sites.

Here's the dealer list I mentioned, but please realize that there are many, many more "out there" on the web.

Good luck and have fun.

Mark Oppat’s OLD RADIO PARTS (Can find just about anything related to vintage radios)
http://www.oldradioparts.net/index.html

PLAYTHINGS of the PAST (Nice selection of replacement transformers)
http://www.oldradioparts.com/

ANTIQUE ELECTRONIC SUPPLY
http://www.tubesandmore.com/

RADIO DAZE
http://www.radiodaze.com/

MOUSER ELECTRONICS
http://www.mouser.com/

MCM ELECTRONICS
http://www.mcmelectronics.com/

MOYER ELECTRONICS
http://www.moyerelectronics.com/index-16.html

JUST RADIOS
http://www.justradios.com/

RENOVATED RADIOS (supplier of excellent reproduction parts for vintage radios)
http://www.renovatedradios.com/

Bob Dobush’s FIND A TUBE (supplier of vacuum tubes)
http://www.findatube.com/

Another good online place is: Bob's Antique Radios at http://www.radioantiques.com/

:Most of us in the vintage radio hobby purchase our parts online.....unless that is, you happen to be fortunate enough to live near a good electronics supply house.
:
:Here's a list of links of dealers that I like to deal with.
:
:You'll have to browse their sites and do some searching to find the parts you need. Some have a minimum order......some do not.
:
:You mentioned that you are a novice to electronics. Having no idea of your actual level of expertise I can only recommend that you take it slow and read up on electronics theory, radio theory, and vintage radio repair before you get in too deep.
:
:This book, available on Amazon.com is a very good one to increase your knowledge:
:
:
:
:You can also click on the "LINKS" option at the top of this page for a nice list of support sites.
:
:
:Here's the dealer list I mentioned, but please realize that there are many, many more "out there" on the web.
:
:Good luck and have fun.
:
:Mark Oppat’s OLD RADIO PARTS (Can find just about anything related to vintage radios)
:http://www.oldradioparts.net/index.html
:
:PLAYTHINGS of the PAST (Nice selection of replacement transformers)
:http://www.oldradioparts.com/
:
:ANTIQUE ELECTRONIC SUPPLY
:http://www.tubesandmore.com/
:
:RADIO DAZE
:http://www.radiodaze.com/
:
:MOUSER ELECTRONICS
:http://www.mouser.com/
:
:MCM ELECTRONICS
:http://www.mcmelectronics.com/
:
:MOYER ELECTRONICS
:http://www.moyerelectronics.com/index-16.html
:
:JUST RADIOS
:http://www.justradios.com/
:
:RENOVATED RADIOS (supplier of excellent reproduction parts for vintage radios)
:http://www.renovatedradios.com/
:
:Bob Dobush’s FIND A TUBE (supplier of vacuum tubes)
:http://www.findatube.com/
:
:

:Another good online place is: Bob's Antique Radios at http://www.radioantiques.com/
:
::Most of us in the vintage radio hobby purchase our parts online.....unless that is, you happen to be fortunate enough to live near a good electronics supply house.
::
::Here's a list of links of dealers that I like to deal with.
::
::You'll have to browse their sites and do some searching to find the parts you need. Some have a minimum order......some do not.
::
::You mentioned that you are a novice to electronics. Having no idea of your actual level of expertise I can only recommend that you take it slow and read up on electronics theory, radio theory, and vintage radio repair before you get in too deep.
::
::This book, available on Amazon.com is a very good one to increase your knowledge:
::
::
::
::You can also click on the "LINKS" option at the top of this page for a nice list of support sites.
::
::
::Here's the dealer list I mentioned, but please realize that there are many, many more "out there" on the web.
::
::Good luck and have fun.
::
::Mark Oppat’s OLD RADIO PARTS (Can find just about anything related to vintage radios)
::http://www.oldradioparts.net/index.html
::
::PLAYTHINGS of the PAST (Nice selection of replacement transformers)
::http://www.oldradioparts.com/
::
::ANTIQUE ELECTRONIC SUPPLY
::http://www.tubesandmore.com/
::
::RADIO DAZE
::http://www.radiodaze.com/
::
::MOUSER ELECTRONICS
::http://www.mouser.com/
::
::MCM ELECTRONICS
::http://www.mcmelectronics.com/
::
::MOYER ELECTRONICS
::http://www.moyerelectronics.com/index-16.html
::
::JUST RADIOS
::http://www.justradios.com/
::
::RENOVATED RADIOS (supplier of excellent reproduction parts for vintage radios)
::http://www.renovatedradios.com/
::
::Bob Dobush’s FIND A TUBE (supplier of vacuum tubes)
::http://www.findatube.com/
::
All:
May I add BG Micro to the list....they have great prices on caps to use for electrolyte rebuilds, and they ship fast!
Lewis

For the record, this is the power supply for the Motorola FM900 that Robert is dealing with. (Sharpest image I could come up with.)

Thank you all for the helpful replies. My main question was, the transformers and rectifier are all available for purchase? They're not really custom and hard to find? And since I am a novice, can anyone translate the power supply's schematic into a parts list? Once I know what to search the electronics stores for, I should be golden.

:Thank you all for the helpful replies. My main question was, the transformers and rectifier are all available for purchase? They're not really custom and hard to find? And since I am a novice, can anyone translate the power supply's schematic into a parts list? Once I know what to search the electronics stores for, I should be golden.

Robert:
First, let's find out what parts you need. The transformer is probably the only thing you cound need that can't be found just about anywhere, and I doubt it is bad. The transistor and the diode are probably shot, as they come from a time when semiconductors were very unreliable. The filter caps should at least be checked for leakage, if not replaced on general principles. You can Ohm out the power transformer and check for shorts to ground, but I think you will find out it is OK. The transistor has an NTE number, and several places carry NTE, Mouser comes to mind first.
Lewis
:
:

The reason I need a complete parts list is because I don't even have the power supply. Mine is missing, it is a separate unit.

:The reason I need a complete parts list is because I don't even have the power supply. Mine is missing, it is a separate unit.

Ok, then, start with the transformer. Are you converting 120 volts from the wall outlet to 12 volts DC? Some other voltage?
You will need to know what the current demand is of the radio, in Amps.

I have boxes of transformers. Shipping will cost more than the part, sad to say.

:

::The reason I need a complete parts list is because I don't even have the power supply. Mine is missing, it is a separate unit.
:
:Ok, then, start with the transformer. You are converting 120 volts from the wall outlet to 12 volts DC.
:You will need to know what the current demand is of the radio, in Amps. The way I would approach it is to go with a hefty transformer and there will be power to spare, so the power supply will run cool and last forever.
:
:I have boxes of transformers. Shipping will cost more than the part, sad to say.

I found this pic of your radio. http://blog.modernmechanix.com/new-fm-auto-radio/

There is no one design that you have to use for a 12 VDC PS. I have built a few, and just searched for an easy schematic to follow. You start with 12 to 15 volts AC from the secondary of the transformer. Search through second hand stores for old stereos that feel heavy. The weight will be a big power transformer. Then measure the voltages and try to find one pair of secondaries that come close to 12 vac. Then, if you can find a voltage regulator chip that can handle the current draw of your radio, you solder that in and you're good to go. The capacitor helps smooth out the ripple. The chip is screwed to a heat sink, a metal plate, because it dissipates a bit of heat.
:
:
::
:
:

The power supply changes 12 volts DC to 108 volts DC.

:The power supply changes 12 volts DC to 108 volts DC.
:
Sorry, Robert. I thought you had something else going on :>)

To step DC up to DC, you can't simply use a transformer, because it needs AC to work. So I suspect the converter changes the 12 volt DC to AC, then steps it up to 120 or so AC, then rectifies that to 108 DC. (Experts please tell me if I'm out to lunch)

This can be done with store-bought items. Buy a power converter that gives you 120 vac from the car power supply socket. It must be a robust one that can power your vacuum tube radio, so I'd guess 3 amps or more may be needed. Then build a rectifier circuit to convert the 120 vac to 108 vdc. The rectifier again needs to be a heavy duty unit, but that is the key to success. Shop for a full wave rectifier that comes as a unit with a mounting hole that is mounted on the cabinet to dissipate heat from the unit. A voltage regulator may be needed to bring the voltage down to 108 dc. I would check the output from the rectifier and possibly add a ballast resistor, but keep in mind that DC can generate considerable heat. Then you will need a 1000 or 2200 mfd capacitor rated at at least 160 volts to smooth out the ripple.

::The power supply changes 12 volts DC to 108 volts DC.
::
:Sorry, Robert. I thought you had something else going on :>)
:
:To step DC up to DC, you can't simply use a transformer, because it needs AC to work. So I suspect the converter changes the 12 volt DC to AC, then steps it up to 120 or so AC, then rectifies that to 108 DC. (Experts please tell me if I'm out to lunch)
:
:This can be done with store-bought items. Buy a power converter that gives you 120 vac from the car power supply socket. It must be a robust one that can power your vacuum tube radio, so I'd guess 3 amps or more may be needed. Then build a rectifier circuit to convert the 120 vac to 108 vdc. The rectifier again needs to be a heavy duty unit, but that is the key to success. Shop for a full wave rectifier that comes as a unit with a mounting hole that is mounted on the cabinet to dissipate heat from the unit. A voltage regulator may be needed to bring the voltage down to 108 dc. I would check the output from the rectifier and possibly add a ballast resistor, but keep in mind that DC can generate considerable heat. Then you will need a 1000 or 2200 mfd capacitor rated at at least 160 volts to smooth out the ripple.
:

Ok, this is great information! Now I am getting on the right track. Thanks! I did a quick search and saw a rectifier that'll turn 120 AC into 110 DC, do you think 110 is too far over 108?

...And I know that once I get all of these parts, I'm gonna need some help wiring it all together. Good news is that I can solder and have a good Weller WE51, so we're good in that department.

110 VDC will be fine. AFAIK, you are using this to provide plate voltage for the 7 vacuum tubes. They can handle flucuations, no problem. Adding a capacitor may lower the output slightly as well. Experts correct me.

Here's an example of what you can start with for a converter. This technology has come a long way since the 60's.

http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?productId=202539660&storeId=10051&langId=-1&catalogId=10053&MERCH=REC-_-product-1-_-202539667-_-202539660-_-N#.UB_QX6D6OAk

:::The power supply changes 12 volts DC to 108 volts DC.
:::

::Sorry, Robert. I thought you had something else going on :>)
::
::To step DC up to DC, you can't simply use a transformer, because it needs AC to work. So I suspect the converter changes the 12 volt DC to AC, then steps it up to 120 or so AC, then rectifies that to 108 DC. (Experts please tell me if I'm out to lunch)
::
::This can be done with store-bought items. Buy a power converter that gives you 120 vac from the car power supply socket. It must be a robust one that can power your vacuum tube radio, so I'd guess 3 amps or more may be needed. Then build a rectifier circuit to convert the 120 vac to 108 vdc. The rectifier again needs to be a heavy duty unit, but that is the key to success. Shop for a full wave rectifier that comes as a unit with a mounting hole that is mounted on the cabinet to dissipate heat from the unit. A voltage regulator may be needed to bring the voltage down to 108 dc. I would check the output from the rectifier and possibly add a ballast resistor, but keep in mind that DC can generate considerable heat. Then you will need a 1000 or 2200 mfd capacitor rated at at least 160 volts to smooth out the ripple.
::
:
:Ok, this is great information! Now I am getting on the right track. Thanks! I did a quick search and saw a rectifier that'll turn 120 AC into 110 DC, do you think 110 is too far over 108?
:
:...And I know that once I get all of these parts, I'm gonna need some help wiring it all together. Good news is that I can solder and have a good Weller WE51, so we're good in that department.
:

:::The power supply changes 12 volts DC to 108 volts DC.
:::
::Sorry, Robert. I thought you had something else going on :>)
::
::To step DC up to DC, you can't simply use a transformer, because it needs AC to work. So I suspect the converter changes the 12 volt DC to AC, then steps it up to 120 or so AC, then rectifies that to 108 DC. (Experts please tell me if I'm out to lunch)
::
::This can be done with store-bought items. Buy a power converter that gives you 120 vac from the car power supply socket. It must be a robust one that can power your vacuum tube radio, so I'd guess 3 amps or more may be needed. Then build a rectifier circuit to convert the 120 vac to 108 vdc. The rectifier again needs to be a heavy duty unit, but that is the key to success. Shop for a full wave rectifier that comes as a unit with a mounting hole that is mounted on the cabinet to dissipate heat from the unit. A voltage regulator may be needed to bring the voltage down to 108 dc. I would check the output from the rectifier and possibly add a ballast resistor, but keep in mind that DC can generate considerable heat. Then you will need a 1000 or 2200 mfd capacitor rated at at least 160 volts to smooth out the ripple.
::
:
:Ok, this is great information! Now I am getting on the right track. Thanks! I did a quick search and saw a rectifier that'll turn 120 AC into 110 DC, do you think 110 is too far over 108?
:
:...And I know that once I get all of these parts, I'm gonna need some help wiring it all together. Good news is that I can solder and have a good Weller WE51, so we're good in that department.

Robert:
whoops, I misundestood. 110 Volts would be almost a perfect 108 match, you are ususlly givet plus or minus 20% on values and stuff like that.
Lewis

Working on a part list..............

A bit time consuming, but maybe we can come up with something.....hang in there Robert

Dennis

Wow, thank you so much. I owe you one.