23pos rotary switch from triodeelectronics

[jhaible]

I don't find the old thread, so I start a new one.

Bought 5 of these switches
http://store.yahoo.com/triodeel/4pol24posals.html

The arrived last week. Had to pick them up at the German customs office.
19.5% extra - still a good deal.

Man, are these *huge*! Need a lot of space behind the front panel.

Making a 2dB/step bridged T attenuator was easy, using some small pieces of veroboard, soldered directly to the switches, and E96 resistors soldered to the veroboard.

The action is rather hard. Well, as the switch takes up much space behind the panel, I may as well use large 35mm knobs on the front.

But I wonder, is it advisable to remove that click-stop action in such a switch? The contacts are make before break, so it should work, but I'm still hesitant. Seems once this steel ball is removed, it may be hard to fit in again. Any hints?

JH.

 

[gary o]

Wow! nice switches been on the look out for something like those thanks for that, im very interested in the bridged T attenuator you have made, I gotta make something like that for a homemade BA6A limiter.

Many thanks ?.Gary O.

 

[AMZ-FX]

19.5% extra - still a good deal.

Geez, I thought 9% here in the southern USA was a raw deal... you guys need to stage a tax revolt! :grin:

That's one for you 19 for me....

-Jack

ps: thanks for the report on the switches. I've been wondering about the quality of them.

 

[radiance]

[quote author="jhaible"]



But I wonder, is it advisable to remove that click-stop action in such a switch? The contacts are make before break, so it should work, but I'm still hesitant. Seems once this steel ball is removed, it may be hard to fit in again. Any hints?

JH.[/quote]

May I ask: why would you do THAT?

 

[alk509]

[quote author="radiance"]why would you do THAT?[/quote]

Continuous rotation?

Peace,
Al.

 

[jhaible]

[quote author="alk509"][quote author="radiance"]why would you do THAT?[/quote]

Continuous rotation?

Peace,
Al.[/quote]

Yes. (;->)

Does this work with that kind of switch?

JH.

 

[jhaible]

[quote author="gary o"]Wow! nice switches been on the look out for something like those thanks for that, im very interested in the bridged T attenuator you have made, I gotta make something like that for a homemade BA6A limiter.

Many thanks ?.Gary O.[/quote]

You're welcome - some friendly member of this forum pointed me to these switches.
I can scan the drawing with the resistor values and post it tonight, I hope.

JH.

 

[PRR]

> remove that click-stop action in such a switch?

Yes. You don't really want it in a volume control, it isn't hard to get out, and may not be all that hard to put back if you change your mind.

 

[Zilla]

Two issues come up if you remove the ball:

1. Loss of repeatable settings.

2. Loss of constant impedence. If the wiper comes to rest between two contacts, you will effectivly short a resistor in the shunting resistor chains. If the circuits feeding or receiving signal from the attenuator are sensitive to impedence (like a passive eq unit) you may get unexpected results.

Other than that you probably won't have any problems when used as a simple volume control.

 

[matthias]

@jürgen:

I also need some switches like this...

what do you think of the mechanical quality of the switch??

 

[mcs]

The switches are the kind that's used in Japanese scopes (like my Leader). I think the quality is OK, as long as you use them - they will probably go bad if they are not used enough.

Best regards,

Mikkel C. Simonsen

 

[jhaible]

[quote author="gary o"]im very interested in the bridged T attenuator you have made, I gotta make something like that for a homemade BA6A limiter.

Many thanks ?.Gary O.[/quote]

Here's the drawing:

http://www.oldcrows.net/~jhaible/vari_mu_compressor/jh_2dB_steps_attenuator.pdf

Tried to post the *.xls file for calculation, too, but ftp problems again.

JH.

 

[jhaible]

and here's the xls file:

http://www.oldcrows.net/~jhaible/vari_mu_compressor/bridged_t_2dB_steps_1.xls

JH.

 

[gary o]

Thanks JH your a true gent :grin:

Regards Gary O.

 

[jhaible]

[quote author="matthias"]@jürgen:

I also need some switches like this...

what do you think of the mechanical quality of the switch??[/quote]

Hard to tell. No gold or such. From the *looks* of it, it doesn't look much better than the cheap open frame switches I can buy from Reichelt - only that it has so many positions.
If I were only building a potentiometer configuration , I'd rather go for a real good potentiometer for that amount of money. But for constant impedance stuff, what else could I do?

JH.

 

[jhaible]

... and photos of the veroboards + resistors attached to the switch:
http://www.oldcrows.net/~jhaible/vari_mu_compressor/attenuator_pics/DSCN2375.JPG
http://www.oldcrows.net/~jhaible/vari_mu_compressor/attenuator_pics/DSCN2376.JPG
http://www.oldcrows.net/~jhaible/vari_mu_compressor/attenuator_pics/DSCN2377.JPG

JH.

 

[jhaible]

You can see that I have removed 2 of the 4 poles/levels, as the whole assembly would not have fit into the already-stuffed enclosure.
The axis still has its full lenght - whichfortunately will fit in.

JH.