PT wiring Hammond 270DAX

[tubenit]

Just wanted to double check something before picking up a PT for a project for a friend.

When I've used Hammond PT's in the past, they have typically been listed something like 260-0-260 @104ma. 

Yet this 270DAX is listed as 520CVT @104ma.  I'm not understanding why they list it that way instead of 260-0-260?

I plan to use a solid state rectifier to save room on the chassis. Build will be around the size of a Princeton Reverb.

My understanding is the red/yellow wire on the PT would be grounded to chassis and this is not an "internal wire" but actually an external wire grounded to the chassis. 


Q1) Is the way I have drawn the schematic correct for using this PT?


Q2) Using the 260v x 1.4 (solid state rectifier) would the 364v on node A be a reasonable expectation?

Thanks, Tubenit

[sluckey]

When I've used Hammond PT's in the past, they have typically been listed something like 260-0-260 @104ma. 

Yet this 270DAX is listed as 520CVT @104ma.  I'm not understanding why they list it that way instead of 260-0-260?

Q1) Is the way I have drawn the schematic correct for using this PT?


Q2) Using the 260v x 1.4 (solid state rectifier) would the 364v on node A be a reasonable expectation?

AFAIK Hammond has always listed their transformers as 520V C.T. rather than 260-0-260. Both methods of expression are exactly the same. Look here for an example...

     https://www.hammfg.com/electronics/transformers/classic/200

Schematic looks fine. And you should expect 364VDC unloaded B+.

[tubenit]

Always grateful for your excellent help and advice, Sluckey!  Very appreciative.  Thank you!


With respect, Tubenit

[tubenit]

I am thinking this 270 DAX  6.3v wiring does NOT have an internal center tap ground? 


Is that correct?   I was planing on an artifical CT using 100 ohm resistors.


with respect, Tubenit

[Ronquest]

I am thinking this 270 DAX  6.3v wiring does NOT have an internal center tap ground? 


Is that correct?   I was planing on an artifical CT using 100 ohm resistors.


with respect, Tubenit

Hammond shows, NO center tap for the 6.3 winding and only green to green for wiring.  Same with real pictures I've seen.

[sluckey]

I am thinking this 270 DAX  6.3v wiring does NOT have an internal center tap ground? 

It does not. But it's very easy to check. One day you may have the same question about an unknown PT.

Connect one ohm meter probe to a green wire. Touch the other probe to the PT shell. Should read infinity (OL, etc). Now touch the red/yellow HT center tap. Shouls also read infinity.

[scstill]

BTW - I've used similar to this PT before. Might be obvious but if your wall is 120v and you use the gray Primary (117v) you should get a little more volts out. And less out if you use the black primary. 100ohm artificial CT on green wires worked for me.