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Maranz 2500, 2600 Transformer Design

Someone is going to have to measure ithe filament voltage on a working unit, I have Googled my fingers to the bone looking for info on these scope tubes to no avail.

Tom
 
SoCal Sam said:
Are you missing any boards or is your P800 or P900 messed up?
Click to expand...

No. I don't have any transformer in the unit. It had been tossed out by the previous owner. With the help of your link to 4400 SM, I barely came up with 150v AC for the 180v supply. I still am missing the info to the CRT filament voltage. As Catrafter said in post #21, someone is going to have to measure the filament voltage in a working unit.
 
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mech986 said:
http://www.radiomuseum.org/tubes/tube_50tb31.html

This gives pinout so someone with a 2500 could measure the filaments I guess. That would give you what it gets, but is it regulated or produced in some fashion rather than just a winding off the tranny?
Click to expand...

Or you can measure from the leads in the red box in the picture (The filament is connected straight from the winding with -576v DC tapped to it):

picture.php
 
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I found a Marantz 2130 scope tuner. From what I found, it contains 50TB31 Hitachi tube. Looking at the schematic of 2130, I found it showing the filament voltage to be 7v. Does it sound about right?

If so, this is what I got so far:

~8v AC for the Lamps

7v AC for the tube filament

~29v AC for +/- 40v

~150v AC for 180v

~407v AC for -576v

~124vct AC for the main amps per channel (~133vct AC for 2600).

If I'm correct for above, then it's time to figure out the current. That should be the easier part.
 
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ccheath said:
Or you can measure from the leads in the red box in the picture (The filament is connected straight from the winding with -576v DC tapped to it):

picture.php
Click to expand...

Can someone confirm that what you are asking is safe to measure. THIS IS A VERY IMPORTANT QUESTION WHEN ASKING A FAVOR OF ANOTHER 2500 OWNER.

2500.jpg
 
SoCal Sam said:
ccheath said:
Or you can measure from the leads in the red box in the picture (The filament is connected straight from the winding with -576v DC tapped to it):

picture.php
Click to expand...
Can someone confirm that what you are asking is safe to measure. THIS IS A VERY IMPORTANT QUESTION WHEN ASKING A FAVOR OF ANOTHER 2500 OWNER.

2500.jpg
Click to expand...

Please can anyone confirm? But keep in mind that the transformer wiring from the 6 wire secondary in SoCal's schematic is wrong. Please see Post #2 of this thread.
 
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ccheath said:
Please can anyone confirm? But keep in mind that the transformer wiring from the 6 wire secondary in SoCal's schematic is wrong. Please see Post #2 of this thread.
Click to expand...

ccheath, the 6 wire secondary is J802 on P800. Are looking for the 4 wire secondary that connects to J801?:scratch2:
 
J801 has the wiring pairs for the lamps and another wiring pairs for the filament. Both BLU and GRN pairs are separate winding. I was looking for the voltage from J801 for the filament.

J802 has the voltage for the 180v supply I needed to know about. It would have been better to measure all the voltage on the 6 wire secondary while anyone's at it.

Again, this is what I got so far (welcome any correction):

~8v AC for the Lamps (more likely 7v)

7v AC for the tube filament

~29v AC for +/- 40v

~150v AC for 180v

~407v AC for -576v

~124vct AC for the main amps per channel (~133vct AC for 2600).
 
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I hope you pull this off. This would make a nice reference. I no longer have a 2500 or I'd help you out any way I could. Good luck!
 
ccheath said:
No Go. :no:

That's their reply:

"Hi;
Sorry, we can only rewind an original supplied to us.
Regards,
TRS"

But thank you for trying.

Big Tuna showed me a link (thank you, Big Tuna):

http://www.temcotransformer.com/toroidaltransformer.html

I also found this:

http://www.toroid.com/index.html

They build new ones but need specs. That's why I did this project. I'm not done yet but I still welcome any correction.
Click to expand...

OK, we have some possible vendors.:yes: What exactly do they need? Do they need a working example so they can take measurements of all the leads? Can they work with a dead transformer, i.e. figure out what the ratings are from the windings and core?
 
paul79 said:
I hope you pull this off. This would make a nice reference. I no longer have a 2500 or I'd help you out any way I could. Good luck!
Click to expand...

I much appreciate it. Right now, I'm at a stage of collecting my transformers and a couple variacs to power that receiver completely. So far, I used the SX-434 transformer with variac to test the lamps which is the easiest and the tube filament. The tube seem to glow properly at 7v. This weekend I plan to power the tuner and pre with +/-40v. Then power the Main Amp with my SX-1980 transformer and then the Scope with tube transformer/variac if time permits. I have all the voltages to get me started. Now I have to figure the current. I think the current should not be less than those fuses listed. Main Amp is something I really have to figure out since there's no fuses for each amp. I'm getting close. I think I can pull this off.

SoCal Sam said:
OK, we have some possible vendors.:yes: What exactly do they need? Do they need a working example so they can take measurements of all the leads? Can they work with a dead transformer, i.e. figure out what the ratings are from the windings and core?
Click to expand...

In order to get the transformer wound, they need the transformer specs. Ex: primary voltage(s), primary configuration(s), all the secondary voltage(s) and current(s), and secondary configuration(s). Transformer size matter too. It must fit inside the receiver while being able to power everything and take the abuse. That's where it's catchy.

As far as working with the dead transformer, the link you sent me is the one that deals with that kind of work.
 
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Didn't get a chance to power it up. I been real busy. Hopefully this weekend. I will keep posting when I get to it.
 
Finally got around doing this. So far, I connected the power to the tuner/preamp and lights. It works successfully. Now, working on connecting the main amp.
 
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