Bendix c213300 output transformer

[scott2000]

Any information on this one?
3lbs 15.8oz
4"tall 3.25"wide 2.5"deep...ish

 

[mjrippe]

Um...you just gave us all the information! What specifically are you looking to find out? At that size it is probably push-pull output from something like a pair of 6V6. No way to guess frequency response. No mention of DC on the primary.

 

[scott2000]

No way to guess frequency response. No mention of DC on the primary.

I'll revisit the testing transformer knowledge base in the future and see what I can learn.

 

[CJ]

maybe a compressor output? 500 to 600 ohms output,

is that a 9 K primary? probably a 6SL7 or 6SN7 output tube type,

 

[emrr]

Primary resistance is more inline with preamp output current, you don't see anything that high with power tubes generally speaking. Need to put an L meter on it.

 

[mjrippe]

Doug is probably right. I was thinking power tube because of the 8 ohm tap.

 

[scott2000]

Need to put an L meter on it.

all I have is a cheapy lcr....
https://www.analogtechnologies.com/multimeter_VICI_DM4070.html

attaching what it has on the primaries ..
I need to dig up some papers from CJ on some tests that should be doable for me.....Pretty sure I can find them easy enough...

 

[emrr]

Pretty low inductance, so don't expect low end unless it's an amp circuit with enough feedback to lower drive Z significantly. Someone else can do the math on drive Z to be reasonably flat at 100/50/25/etc

 

[scott2000]

Pretty low inductance, so don't expect low end unless it's an amp circuit with enough feedback to lower drive Z significantly. Someone else can do the math on drive Z to be reasonably flat at 100/50/25/etc

Just taking some quick measurements with my Fluke 8060A
Across 1&3
1k@ 6.14VAC--- .000048 Amps
100HZ @ 6.07VAC--- .000179 Amps

That seems a bit different..better at least....... guess I'll recheck... should there be less inductance at higher frequencies? Sorry for my ignorance....
Not sure why different test has a different result.. maybe straight up reading w/cheapy meter isn't as valid??
Am I supposed to have the transformer secondaries connected to a load? This is without them being connected...

 

[emrr]

That's not a test I've ever done, not sure what value it holds. Paging CJ.....

 

[Murdock]

Your lcr meter only test at 1Khz. And probably with a low signal level. No wonder you got low readings. Yes, higher test frequencies result in lower inductance readings.
Try the test cj suggest with 50Hz or 60Hz. Depending on where your dmm is most sensitive.

 

[scott2000]

That's not a test I've ever done, not sure what value it holds. Paging CJ.....

ok...I'm not sure where it came from besides here.... Had it saved...
XL=2*pi*F*L....where XL is Volts AC/Amps AC???

Try the test cj suggest with 50Hz or 60Hz

What is the test CJ suggests?

 

[CJ]

Inductance is just a resistance with J operators, so Ohms Law applies,

so you just go

1 K Hz: 14 V-ac / 0.000048 = 291, 667 Ohms (XL)
100 Hz: 6 V-ac / 0.000179 = 33,520 Ohms (XL)

XL = 2 pi f L we want L, so isolate the term L,

L = XL / 2 pi f

i get 46 and 53 H which indicates a gapped core,

I like the "Out-Put" part, never seen that,

 

[scott2000]

1 K Hz: 14 V-ac / 0.000048 = 291, 667 Ohms (XL)

It was 6.14V...Not sure why I didn't just put 6....
so around 20 H?

 

[emrr]

46 and 53 L, that looks better, still need some feedback in a tube circuit to push the lows down, but not tons

 

[scott2000]

46 and 53 L

I believe he misread my 6.14v-ac to be 14v-ac....

so 127,916 ohms (XL)
meaning the 1k would be 20H.....

Does that still make it look gapped?

 

[CJ]

Yeah me bad, 20 H, no gap, need laptop, not phone, and some bi focals! And maybe some speed balls,

So figure about 70 H at 20 hz.

Run that thing all day at 100 hz and watch the Henrys go up to 100 if it has not been plugged in for 50 or 70 years.