Daven Fixed Pad

[guitarrock04]

I've got an old Daven fixed attenuator that came in a box of random bits from a swap meet.

It's a nice wire wound piece, labelled Fixed Pad Type: 1532, Circuit Bal "H", Impedance: 600/600/600/600, Attenuation: 10

Thus, I would assume its a 10db @ 600ohm fixed pad, which is perfect for the output of my 436C...

I can't find any info on it and wanted to make sure I'm connecting it properly. There are 9 connections, labelled 1-2, 5-6, 7-8, 9-10, with C in the middle.

Measured resistances are as follows:

Pin 1 gives 42k to 2, 6, 8, and 10

Pin 1 gives 21k to common

Pin 1 gives 317R to 5, 7, and 9

So if 1 and 2 were my balanced inputs, I can take signal from any of the 5-6, 7-8, 9-10 pairs, right?

If signal in were on pin 1, that would correlate to signal out on 5-9, right?

Any clarification would be greatly appreciated.

 

[emrr]

I believe that's a splitting pad.  Your interpretation appears correct. 

 

[abbey road d enfer]

Measured resistances are as follows:

Pin 1 gives 42k to 2, 6, 8, and 10

Pin 1 gives 21k to common

Pin 1 gives 317R to 5, 7, and 9

So if 1 and 2 were my balanced inputs, I can take signal from any of the 5-6, 7-8, 9-10 pairs, right?

If signal in were on pin 1, that would correlate to signal out on 5-9, right?

Any clarification would be greatly appreciated.

According to your measurements, it looks like the nominal attenuation could be achieved only if the output is loaded with 600R (it may even be possible that all outputs need be loaded).

 

[emrr]

Yes, H's and T's require matching loads, or you will have less loss.  An unused tap would typically be loaded with a resistance.  Measure it and let us know. 

 

[guitarrock04]

I guess this is what I'm looking for clarification on...

I understand the concept of an H pad, that the input would be the top of the literal "H" and the output off the bottom, if you will.

I had planned to strap this to the secondary of the output transformer, so you're saying it's necessary to terminate the two unused outputs with a 610 ohm resistor?

 

[abbey road d enfer]

Since we're not certain about the internal structure, it may or may not necessary to terminate the unused outputs, but it is certain that the used output must be properly terminated.