Daven Attenuator Attacked!

[CJ]

Some vandal broke into my house and did a Daven dissection right on my kitchen counter while I was at work.
If I ever catch the guy... :razz:

This used to be an atenuator:

The back. Those aluminum posts are the contacts for that wiper you see.

One part of the wiper goes to the ring, the other to the contacts.
The gear sits against a spring loaded bearing for the detents:

Here are some of the resistors inside.
Weird wax wire windings:

Higher value resistors wound on posts:

Close up:

Here is another type with different contacts:

What is the purpose of this thread?
I am still trying to figure that out. :?

 

[NewYorkDave]

They're nicely-made, aren't they? We won't see their like again.

I once opened up a Shallco 600-ohm ladder (21 steps, 2dB/step plus taper to "off") and drew a schematic. I'll post it sometime if there's sufficient interest.

The other common constant-impedance configuration was the bridged-T, which had no minimum insertion loss but required twice as many contacts. The attenuator shown in CJ's last photo is probably a bridged-T, and a pretty deluxe one at that. Judging by the number of steps, it's probably 1.5dB/step. Such a control was often used as a "board master" in a mixing console, with the less-deluxe 21-step ladder type used as individual channel faders.

EDIT: DUH, I just bothered to look at the full-size photo. The answer's right on the label: it's 1dB per step, 50dB total. Since it doesn't have a taper and "off", it probably came from something like a gain set or other measuring gear, rather than from a mixing console.

 

[gary o]

Is it something like this on the RCA BA6A guys.

cheers Gary O.

 

[Rob Flinn]

Is it something like this on the RCA BA6A guys.

Yes

 

[verbos]

You guys know about this?

http://goldpt.com/

sort of interesting.... expesive, but interesting. Couldn't one do something similar from a regular rotary switch?

Mark

 

[CJ]

Those are nice. You can solder yourself and save a buck.

 

[core13]

someone know how to open a daven attenuator? the pictures are not available anymore.
I have a 500ohm daven that is internally open and I would like to fix it
thank you