9P6 power supply

3/15/2008 4:40:55 PMKris

Hi, I am rebuilding the 9P6 on my Majestic 92 and have a couple of questions. First 2 of the filters are bad and need replaced, are all 4 of the large capacity caps located in the tall part of the power supply on the opposite side of the rectifier? I would assume they are because of the size and the 300 gallons of tar that may need to be melted. And is the 2000 ohm resistor between the red and green terminal inside there too, if it is I want to replace it with a modern one so what wattage should I use and what is the wattage of the two resistors on top of the unit, they test good but while I am in there I plan on replacing them too Any other tips besides replacing the wire that crumbles when you look at it wrong?
Thanks!

3/15/2008 5:03:54 PMTerry F

Kris,

I rebuilt a 7P6 with the invaluable help from Radiodoc on this forum.

My plan was to leave the tar items in tct and mount the new replacement parts on a PCB which I mounted on the end of the power supply.

Rewire the the power supply like I did and you will have a very nice radio.

Terry F

3/16/2008 1:21:51 PMThomas Dermody

You do not need to replace the original resistors. They are most likely wire wound, and will function well for many more years. The capacitors are what go bad. Replace them. They are non-electrolytic. You may use electrolytics as replacements, and may go larger in value if you wish, though you may also maintain the original tuned configuration with the original values. If you go larger with the main values, omit any going across chokes.

3/17/2008 7:31:25 AMDavid S

Kris,

The resistors you are talking about are inductors,I know because I removed the tar/wax from my 9P6 (found it open along with damaged caps in that case). I plan on re-winding my inductor and re-installing it in the can, along with new capacitors. The inductor uses 30 or 32 gage wire, which I need to order, as well as making a bobben/form to wind the wire on to. The core is made of many layers of E/I core laminates, which I saved to reuse.

To remove the tar/wax, I used a paint remover heat gun to warm the case up and catch the run off in an old cookie sheet. I plan on dis-carding the tar/wax and just use plastic material and TRV to hold everything in place when I put it back together.

David S

:Hi, I am rebuilding the 9P6 on my Majestic 92 and have a couple of questions. First 2 of the filters are bad and need replaced, are all 4 of the large capacity caps located in the tall part of the power supply on the opposite side of the rectifier? I would assume they are because of the size and the 300 gallons of tar that may need to be melted. And is the 2000 ohm resistor between the red and green terminal inside there too, if it is I want to replace it with a modern one so what wattage should I use and what is the wattage of the two resistors on top of the unit, they test good but while I am in there I plan on replacing them too Any other tips besides replacing the wire that crumbles when you look at it wrong?
:Thanks!

3/17/2008 11:09:12 PMKris

Well I sucessfuly extracted the choke from the tar without damaging it, what a job, now on to the rebuild......

:Kris,
:
:The resistors you are talking about are inductors,I know because I removed the tar/wax from my 9P6 (found it open along with damaged caps in that case). I plan on re-winding my inductor and re-installing it in the can, along with new capacitors. The inductor uses 30 or 32 gage wire, which I need to order, as well as making a bobben/form to wind the wire on to. The core is made of many layers of E/I core laminates, which I saved to reuse.
:
:To remove the tar/wax, I used a paint remover heat gun to warm the case up and catch the run off in an old cookie sheet. I plan on dis-carding the tar/wax and just use plastic material and TRV to hold everything in place when I put it back together.
:
:David S
:
::Hi, I am rebuilding the 9P6 on my Majestic 92 and have a couple of questions. First 2 of the filters are bad and need replaced, are all 4 of the large capacity caps located in the tall part of the power supply on the opposite side of the rectifier? I would assume they are because of the size and the 300 gallons of tar that may need to be melted. And is the 2000 ohm resistor between the red and green terminal inside there too, if it is I want to replace it with a modern one so what wattage should I use and what is the wattage of the two resistors on top of the unit, they test good but while I am in there I plan on replacing them too Any other tips besides replacing the wire that crumbles when you look at it wrong?
::Thanks!

3/18/2008 10:41:26 AMDavid S

Kris,

How are you planning on taking the chock apart? I ended up cutting thru the windings to pull them out of the core, only to find out that with a little additional time, I could have sperated the laminations using a knife to brake the bond and pull them out of the cardboard bobben/holder. Although it made a mess, cutting the windings, it allowed me to count the layers and the number of windings per layer. Since I am at work, I do not have the winding/layer information with me, so will have to wait until I get home to up load that information.

David S

:Well I sucessfuly extracted the choke from the tar without damaging it, what a job, now on to the rebuild......
:
:
:
:
:
::Kris,
::
::The resistors you are talking about are inductors,I know because I removed the tar/wax from my 9P6 (found it open along with damaged caps in that case). I plan on re-winding my inductor and re-installing it in the can, along with new capacitors. The inductor uses 30 or 32 gage wire, which I need to order, as well as making a bobben/form to wind the wire on to. The core is made of many layers of E/I core laminates, which I saved to reuse.
::
::To remove the tar/wax, I used a paint remover heat gun to warm the case up and catch the run off in an old cookie sheet. I plan on dis-carding the tar/wax and just use plastic material and TRV to hold everything in place when I put it back together.
::
::David S
::
:::Hi, I am rebuilding the 9P6 on my Majestic 92 and have a couple of questions. First 2 of the filters are bad and need replaced, are all 4 of the large capacity caps located in the tall part of the power supply on the opposite side of the rectifier? I would assume they are because of the size and the 300 gallons of tar that may need to be melted. And is the 2000 ohm resistor between the red and green terminal inside there too, if it is I want to replace it with a modern one so what wattage should I use and what is the wattage of the two resistors on top of the unit, they test good but while I am in there I plan on replacing them too Any other tips besides replacing the wire that crumbles when you look at it wrong?
:::Thanks!

3/19/2008 4:18:49 PMKris

Luckilly the choke tested fine so I will not have to rebuild it. The most I have ever wound where coil forms and I have not ever attempted doing a transformer/choke so there is no advice along that path I could give you.

:Kris,
:
:How are you planning on taking the chock apart? I ended up cutting thru the windings to pull them out of the core, only to find out that with a little additional time, I could have sperated the laminations using a knife to brake the bond and pull them out of the cardboard bobben/holder. Although it made a mess, cutting the windings, it allowed me to count the layers and the number of windings per layer. Since I am at work, I do not have the winding/layer information with me, so will have to wait until I get home to up load that information.
:
:David S
:
::Well I sucessfuly extracted the choke from the tar without damaging it, what a job, now on to the rebuild......
::
::
::
::
::
:::Kris,
:::
:::The resistors you are talking about are inductors,I know because I removed the tar/wax from my 9P6 (found it open along with damaged caps in that case). I plan on re-winding my inductor and re-installing it in the can, along with new capacitors. The inductor uses 30 or 32 gage wire, which I need to order, as well as making a bobben/form to wind the wire on to. The core is made of many layers of E/I core laminates, which I saved to reuse.
:::
:::To remove the tar/wax, I used a paint remover heat gun to warm the case up and catch the run off in an old cookie sheet. I plan on dis-carding the tar/wax and just use plastic material and TRV to hold everything in place when I put it back together.
:::
:::David S
:::
::::Hi, I am rebuilding the 9P6 on my Majestic 92 and have a couple of questions. First 2 of the filters are bad and need replaced, are all 4 of the large capacity caps located in the tall part of the power supply on the opposite side of the rectifier? I would assume they are because of the size and the 300 gallons of tar that may need to be melted. And is the 2000 ohm resistor between the red and green terminal inside there too, if it is I want to replace it with a modern one so what wattage should I use and what is the wattage of the two resistors on top of the unit, they test good but while I am in there I plan on replacing them too Any other tips besides replacing the wire that crumbles when you look at it wrong?
::::Thanks!

3/20/2008 7:38:29 AMDavid S

Kris,

Good for you in finding the choke to be ok, of the three (one in the box with the capos and two in a separate can) in my radio, one failed open (its the one in the can with the caps), so I will be rewinding mine sometime this spring.

David S

:Luckilly the choke tested fine so I will not have to rebuild it. The most I have ever wound where coil forms and I have not ever attempted doing a transformer/choke so there is no advice along that path I could give you.
:
:
:
::Kris,
::
::How are you planning on taking the chock apart? I ended up cutting thru the windings to pull them out of the core, only to find out that with a little additional time, I could have sperated the laminations using a knife to brake the bond and pull them out of the cardboard bobben/holder. Although it made a mess, cutting the windings, it allowed me to count the layers and the number of windings per layer. Since I am at work, I do not have the winding/layer information with me, so will have to wait until I get home to up load that information.
::
::David S
::
:::Well I sucessfuly extracted the choke from the tar without damaging it, what a job, now on to the rebuild......
:::
:::
:::
:::
:::
::::Kris,
::::
::::The resistors you are talking about are inductors,I know because I removed the tar/wax from my 9P6 (found it open along with damaged caps in that case). I plan on re-winding my inductor and re-installing it in the can, along with new capacitors. The inductor uses 30 or 32 gage wire, which I need to order, as well as making a bobben/form to wind the wire on to. The core is made of many layers of E/I core laminates, which I saved to reuse.
::::
::::To remove the tar/wax, I used a paint remover heat gun to warm the case up and catch the run off in an old cookie sheet. I plan on dis-carding the tar/wax and just use plastic material and TRV to hold everything in place when I put it back together.
::::
::::David S
::::
:::::Hi, I am rebuilding the 9P6 on my Majestic 92 and have a couple of questions. First 2 of the filters are bad and need replaced, are all 4 of the large capacity caps located in the tall part of the power supply on the opposite side of the rectifier? I would assume they are because of the size and the 300 gallons of tar that may need to be melted. And is the 2000 ohm resistor between the red and green terminal inside there too, if it is I want to replace it with a modern one so what wattage should I use and what is the wattage of the two resistors on top of the unit, they test good but while I am in there I plan on replacing them too Any other tips besides replacing the wire that crumbles when you look at it wrong?
:::::Thanks!

3/26/2008 8:15:09 PMDavid S

Found the winding information for the inductor, there are 39 layers, each with 221 turns. The wire size is 36 awg.

David S

3/29/2008 2:43:02 PMKris G

Thanks, and boy does it sound fun to do!

:Found the winding information for the inductor, there are 39 layers, each with 221 turns. The wire size is 36 awg.
:
:David S
:
::Hi, I am rebuilding the 9P6 on my Majestic 92 and have a couple of questions. First 2 of the filters are bad and need replaced, are all 4 of the large capacity caps located in the tall part of the power supply on the opposite side of the rectifier? I would assume they are because of the size and the 300 gallons of tar that may need to be melted. And is the 2000 ohm resistor between the red and green terminal inside there too, if it is I want to replace it with a modern one so what wattage should I use and what is the wattage of the two resistors on top of the unit, they test good but while I am in there I plan on replacing them too Any other tips besides replacing the wire that crumbles when you look at it wrong?
::Thanks!