atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems 107A Loudspeaker w/ 565HK

Hello all,

I've got a matching black 565HK and 107A loudspeaker in like new condition. Is there a way to safely use it without a power supply without damaging the unit? It will work (not super loud, but usable) if I connect the four leads to the each of the handset leads. Is it alright to do this? I know it isn't the correct way...

If someone does have a power supply that's sitting around unused, I'd love to give a new home...PM me

Thanks,

Scott

Scott -

The 107 (spokesman or orator) requires 18vac to function properly. It will work with a 2012b transformer OR with 18vac found on all 1A2 power supplies.

Connect the red wire from the 107 to terminal R on the phone's network. Connect the green wire to terminal GN on the network and connect the black and yellow wires to 18 volts AC from the power supply. If you need an external transformer, I probably have one, but why use one if you've got a working 1A2 system?

Sam

Actually, the R and G leads on a 107A (and the later version, the 107B) are not capacitively-coupled as they feed the input of the amplifier. If you put them across the T & R you are placing a direct short across the pair. The design intends you to put the R and G leads across the receiver leads in the set (in parallel with the two white handset cords leads on the network screws.)

This method has two advantages: It is capacitively-coupled, by design of the network's receiver circuit, and the volume of the local and distant speech will be equalized by the network. Putting the leads on the T & R will result in very high level when you speak, and very low level when the distant party speaks. Using the receiver leads will make both ends have equal loudness.

You can send 18Vac to the set from the KSU on any spare pair, for instance, one of the yellow pairs, and terminate them on spare screws for the Spokesman® power feed.

The later 107B solved the capacitor problem, by using a 6-lead mounting cord, with the R and G being the same as the 107A, but the Bl and W leads have capacitors in series with them. Both pairs (R&G, W&Bl) go to the same input of the amplifier.

One caution: You may get A-C hum in the speaker if you use the grounded 18 Volts from the key system power unit. If you do, reverse the power leads, or use an outboard isolated transformer at the KSU location.

You can easily modify the Spokesman (or any other device needing speech-isolation caps), by cannibalizing the 0.47mFd caps from a 400D KTU. Just connect them to the screws inside the speaker in series with the R and G leads.

You guys never cease to amaze me...

Yes, we are the dinosaurs your Mother warned you about.

Arthur, in those 15 years on hold, have you heard any good songs?

Those first 15 years when the most of the HOLD was endured were in the 1970's and early 80's. Music on hold was not a typical feature, so "no" I didn't hear many good songs then. What I DID hear were dozens of other repairmen, also on hold, because the way the holding bridges were designed allowed a very faint signal to cross over from one line to the next. If you shouted into the test set, you might be able to get other guys to hear you, resulting is a very weird multi-person conversation.

I got to read many books when on hold. All the original James Bond, Travis McGee and Nero Wolfe/Archie Goodwin. Read Ulysses from front to back (talk about an amazing, yet mind-numbing book) and tried several times to read War & Peace, but could only get through the first chapter, about 8 times.

To get back to the subject of Spokesmen, most of us carried one, with a couple of 9-volt batteries taped to it, to be put across the pair when we were on hold. This allowed us to put the test set down on the floor while reading with the angle flashlight above the cross box terminal. When the tester came on the line, we would quickly grab the test set and get back to work. (Yes, we put caps in series with the R & G leads).

I saw many more Spokesmen in use by field employees (and on phone company bosses' desks) than I ever did on subscribers' premises. Same thing with 4A speakerphones.

out here would use as speakers for our portable radios, and tie then to the wands for louder toning, but mostly as the speaker for shout down circuits in stock houses

Yes, the good old crosstalk. I've listened to so many of the Evan Doorbell tapes so I'm familiar with it. Wish I couldv'e been around to toy around with the old network. It really was "alive," in its own way.

Scott

Alright, so I've had a look at my KSU and it has a 28D2 power unit, with two taps for 24VDC, and one for 10VAC lamps and one 18VAC, which I'm assuming is normally for buzzers. What would be the best way to accomplish pushing the 18VAC to the Spokesman without setting my room on fire?

Also, I have another random question... I have a 4-line W/E KSU. The cover says the ringer equivalence is 5.0A. Why so high?

Thanks guys!