sundance-communications.com/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems 1a2 buzzer with volume control

So I was not aware 1a2 buzzers had an option for volume control. A new 2565HKM phone I received had one.

I noticed because it wasn't buzzing when I hooked it up, and when I opened it to investigate, realized that its volume knob was turned all the way down. I kept power to the buzzer as I turned it up, and realized it has a really nice range of volume, from very loud to barely audible/a whisper.

Here's a pic:


I didn't find a reference to this in BSP 501-120-100 (Issue 11/1980).

I have 8 phones currently (for a video demo to come), and only one phone has this kind of buzzer.

Is this unusual, or perhaps a special order device?

Or maybe it's a post-breakup, non-bell system add-on, as I don't recognize the logo, which appears to be a large "S" with "CC" below, and a number "402" stamped into the metal.. all of which can be seen in the above pic. (Maybe Stromberg Carlson?)

Just curious. Wish all the phones had this easy to change volume knob.

And I guess I've never tried; the "standard" buzzers I've seen all have a nylon post with a slot cut in it sticking out of the center of the metal case, that kinda looks like it could be a screw head; can one twist that to control volume?

And all this time I've just "loosened/tightened" the screw to change the sound. Turning the screw too tight mutes the buzzer and too loose makes it sound like somethings falling apart..

Ah, thanks.

So that little nylon post with the slot on the "regular" buzzers really is an adjustable screw. I often suspected, but never tried tweaking it because it wasn't clear that's what it did. I figured it was just a manufacturing artifact, and figured if it were an actual volume control, there'd be a clear stamp on it saying LOUDER and an arrow, like the dial on the bottom for bells, and apparently as written on this knob.

A buzzer with an actual knob is a first for me. I guess it's just an attachment over the nylon screw; didn't try tugging to see if it was just mounted over a regular buzzer.. didn't wanna break it.

The stamped word LOUDER is there for the subscriber. A telephone technician doesn't need to be told that the buzzer is adjustable.
Try putting a diode in series with the buzzer and you'll get a whole nuther type of sound out of it. More like a burp, than a buzz. We did that when there was more than one buzzer in a phone. Generally, one buzzer for the dial intercom, and one for the secretary/boss button & buzzer intercom. Or we would put the diode on the secretary's button, if there weren't enough conductors for two buzzers.

I don't remember what sub-contractor supplied the 10 Vac ones. Definitely not WE, since they had a KS- number. Maybe Suttle. Try the Google. Then let us know.

I remember those buzzers, but I don't remember them being non-WE. They began showing up in WE2565 sets that we were purchasing as new-old stock from Bell South surplus sales. All they did was mimic adjusting the center screw on the original 8A buzzers and they worked well. I'm positive that Suttle didn't make these. I never used anything other than 10VAC for intercom buzzers though, since the ones with blue leads were rated for that. Did you try using 18VAC on these to see if there's any difference in the adjustment of volume?

Ive got some of the 90v black ones . Seems like we used to use them instead of a diode matrix on co ringing in a pinch

Hi Arthur,

Would any diode do? Sounds like a fun thing to add to make the phone burp!