atcomsystems.ca/forum Forums General General Telephone & Systems Information Whats the right thing to call it/what's in it?

When I was a kid I took apart a phone (probably a 500). For lack of a better term (i.e. what do you call it?) - the terminal block where all the connections join together?

Also, what is inside of that thing? And, since not all phones have it, why is it needed? I can see the need for a place to connect everything together... but that's about it.

Anyway, as I said, I took (rather tried to) take one apart when I was about 8. Pried up the tabs, but could only get it out about 1/2". Was immediately confronted with a bunch of goo, and decided maybe this isn't such a healthy thing to be getting on me. (This was the same time when rampant warnings were running around to not take apart a golf ball, as at the core was a substance that would burn, blind and cripple you).

Whats in there, why is whatever in there needed, and what's with the goo?

Thanks
Matt

It was the network. I never took one apart so I have no idea what was inside them.

I think You were a lot like me when I was a kid. I was always taking my toys apart to see what was in them. Sometimes I managed to get them back together.
But it paid off I think, I scored 100 percent on the mechanical portion of the asvab test when I joined the Air Force.

Thanks! Network. Easay enough to remember.


Oh yeah.. we were alike. from TV sets to radios, anything that plugged in. Used my first pair of wire cutters on a live lamp cord. That was fun. They tell me I spent most of my toddler years sticking things in receptacles.

Then there was the time I got a plug fuse cause I thought it was a really cool looking light bulb. For about 1/10000000 of a second it really was. A little bright though.

I too had mixed results on getting things back together. But I'd say I had about a 65% success rate, most times actually fixing something. It really freaked people out when a 7 year old put in a car stereo or fixed their brake lights for 'em.

I don't remember my ASVABS... They were good enough to qualify me for a lot of the more technical ratings (Navy).. but sure wasn't 100%.

Never have understood Math.

When I was a kid, starting about age 9, I got a new Timex every Christmas. It would last until about the following November. When I was about 14, I decided to investigate why my latest watch had stopped. Got the back off and, son-of-a-gun, there was an eyelash in there jamming what I later found out was the balance wheel. Sooooo, I removed it. all 3 feet of it! It was actually the broken mainspring. I just slid the mess off the side of the desk into the trash basket and got a new watch for Christmas, as usual! John C.

lol

John - for future reference - there's this dial on the side you have to wind from time to time. Actually, if you pull out on it.... you can even set the time!!!!

Matt, back to your original question, yes that was an early-vintage 425 type network. Many of the terminals on the top are blind (i.e: tie points), but five of them are associated with the balancing transformer. The two wires of the phone line go in on terminals C and RR. The three wires going to the handset go to terminals B, R and GN (actually two of the handset wires end up going to terminal R. The goo was in there to basically make the network much more resistant to shock if the phone was dropped. These things were so reliable that they were riveted to the base.

All phones have some form of network, just in various configurations. Western Electric had about five different ones, some to fit inside smaller phones, etc. They eventually stopped filling them with goo in the late 1970's. ITT and Sromberg Carlson switched over to a PC-board type network around that same time. At this point, phones were becoming disposable. A network that would last a lifetime was a great idea when phones were being rented.

Matt, real phones, such as all those based upon the circuitry of the 500 set, exhibit a trait called "sidetone." It is the effect that allows you to hear your own voice at a correct level, while conversing with the person at the distant end. It can be remembered by visualizing the "side" of your head, where the handset goes.

In generic terms, the 425-type WE "network" is a hybrid coil, or transformer, and a few capacitors. You need to see an older version of a BSP that shows the actual schematic, rather than a newer BSP that just shows the block diagram.

There are no phones that do not have some electrical equivalent of a network. The goo is silicone compound. Earlier ones had some sort of black crap in them. Later ones were open-air affairs, like the 4228-series, and their guts are visible.

The hybrid is arranged so that there is just the exact amount of sidetone so that your voice is reproduced in your receiver unit at a balanced level, taking into consideration the loop length and your local loop current. If you have too much sidetone, your voice sounds loud to you, and to compensate, you will find yourself speaking too softly. The person at the other end will not be able to hear you properly. Alternatively, if you sidetone is too low, you will find yourself shouting, and the person at the other end will assume that you're either very excited, or drunk.

Seasoned repairmen, working on trunk circuits, can tell if the trunk impedance is set properly, just by listening to the sidetone of a circuit, and they can do that without even establishing a conversation. They just blow softly in the transmitter, and listen to the white noise in their receiver. Too loud or too soft = impedance problems, or equalizers set improperly.

Newer el-cheapo phones occasionally have awful sidetone problems, and an old guy like me will remark on it. Nobody listens, or cares, but we complain anyway.

sidetone

Thanks guys!

Now I understand just a little bit more of this huge puzzle.

I take it that cell phones don't have sidetone, and that's why people yell into them, as they can't hear their own voice?

And I'm glad the goo was just silicone.

Arthur, how about the lack of sidetone on cellphones...

"Newer el-cheapo phones occasionally have awful sidetone problems, and an old guy like me will remark on it. Nobody listens, or cares, but we complain anyway." Amen to that, Arthur. But, I'll bet some day every one of 'em will say, "what'd that old phone guy say about sidetone?" When SWB started doing away with build-out coils and making the compenation in the SLICs, they never thought about G/S trunks, I guess. At least in the 1 C.O. town I lived in, the motel calls were ok to loop start lines, but any time a Motel called a Motel, EEEEEEEEE, or HOLLOW, or well you know. Since we took care of most of the motels in town, once I realized what was going on, I requested a pad of 1-2 Db on all the trunks of the motels we dealt with. BUT, we picked up all but one of the other motels in town, cause we were the only ones that could stop the problem. The others hadn't been padded down yet and just enough gain to EEEEEEE, when they called 1 of 'our' motels, or each other. But all the owners talk and good as well as bad gets passed around, pretty soon all but 1 began to understand that we were 'The Best'. It does my heart good to know that when they call my old outfit, they STILL want to know if and when I'm coming back! OW, I broke my arm patting myself on the back! John C.