atcomsystems.ca/forum
Posted By: Matt1964 ITT 501C Intercom - 09/18/07 11:03 AM
Hello all -

I've been browsing the forum, but can't seem to find exactly what I'm looking for. I have an ITT 501 C Shoebox KSU, (I think it's a 501C, gray cover with an ITT logo in the lower right corner).

So far I've hooked up 2 keysets, and am having lots of fun with the system in general.

The KSU came with a 183981-101-PAK card, which I believe is for intercom functionality between the keysets. I have a number of 10v buzzers, and want to have a go at getting the intercom functionality online.

Problem is, I don't know where to start. Can anyone help? I've seen some posts about what leads to conenct the buzzers to in the keysets, but after that, things get a bit fuzzy. I've also reviewed the schematics over at kadiac.org; but I'm still lost. Even assuming I knew how to wire the stuff up, I'd still be helpless as I don't even know how to use it.... (i.e. what buttons to push to signal another keyset).

Any help is appreciated!

Thanks
Matt
Posted By: justbill Re: ITT 501C Intercom - 09/18/07 11:19 AM
You take the locking screw out of the buttons you want to use for signaling and use the A leads for your signal lead. You have to decide who signals who and wire accordingly. Have fun. Buttons and buzzer Oh my. laugh
Posted By: EV607797 Re: ITT 501C Intercom - 09/18/07 12:29 PM
Matt:

What you have is an ITT 601A KSU, one of the last 1A2 systems made by ITT. The card that you have is a 9-station rotary dial intercom unit. It may have a daughter board attached on it to adapt it for touch-tone use.

This card goes in the bottom slot only, in fact that should be the only slot that will hold it. Near this slot on the 66 block, you'll see rows of clips labeled "T and R" toward the very bottom. There won't be any dial tone on them, just talk battery. You will also see the next rows labeled "LG and L". These are for the line button's lamp. There are no A lead connections required.

In that same area of the block, you'll see ten individual clips numbered 0-9. Note that the numbers are stamped in between the rows, not along the block's fanning strip. You'll connect each buzzer each one of these digits. The other buzzer lead will connect to signal ground (any unused LG or A1 terminal will do). ITT sets use the orange/yellow pair for the buzzer. Western Electric sets use the yellow/green or yellow/orange pair. It really doesn't matter which pair you use.

Operation of the intercom is to simply go off-hook and dial the single digit desired. You won't hear any feedback at all and the intercom path isn't private. The buzzers receive a one-second burst of 10 volts AC when dialed, however they can be repeatedly dialed (or other digits) without hanging up the handset.

If you simply want "button and buzzer" signaling, you will need to have a 401A or 401B card installed in any regular line card slot. From there, you'll need to wire T/R, A and LG/L as if it was a standard line. I don't see the sense in doing this since it appears that you already have a dial intercom card.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/18/07 01:40 PM
Thanks Ed!

I'll be hooking it up tonight, will let ya know what happens. You're right about the card only fitting in one slot, and also about the daughterboard for touchtone phone... which is perfect, cause I have a mix of rotary and touch tone keysets. Can't tell ya how much I appreciate your help....!

Thanks,
Matt
Posted By: justbill Re: ITT 501C Intercom - 09/18/07 01:47 PM
I thought he wanted button and buzzers for the real 1A2 experience. :confused:

Make sure you have the correct voltage for the buzzers, the Bell System equivlent was wire from the factory for 105v intercom ringing, buzzer would click, once. I'm not sure what factory wiring would be on what you have.
Posted By: jeffmoss26 Re: ITT 501C Intercom - 09/18/07 03:10 PM
I was watching a clip on YouTube of the show home improvement. He had the 1A2 phone and speaker. I never noticed before on those phones how the lights blinked. Here's the clip:
Posted By: Matt1964 Re: ITT 501C Intercom - 09/18/07 04:32 PM
Hey all -

Well, some success, but not quite there yet. I go off hook, and press line 5. Line 5 lights, and I've got talk capability. But no buzz when pressing the number I punched down to. So, I put a voltmeter between LG and "0" (actually I tested through "9").... I'm guessing I should see around 10 volts, but.... nothing. I do hear the relays click on the intercom card though.

I noticed there are some jumpers on the intercom card, but am relectant to mess with them since I don't know what they are for.

Any ideas?

Thanks!
Matt
Posted By: justbill Re: ITT 501C Intercom - 09/18/07 04:36 PM
What are the buzzer leads cut to in the set and is that where you punched them down? Did you check both AC and DC with your meter?
Posted By: Matt1964 Re: ITT 501C Intercom - 09/18/07 04:47 PM
On the ITT set, they are cut to Orange/Yellow. On the WE set, Yellow/Green. As for the AC/DC, yep, checked both, nothing there.
Posted By: Arthur P. Bloom Re: ITT 501C Intercom - 09/18/07 05:29 PM
Quote
Originally posted by jeffmoss26:
I was watching a clip on YouTube of the show home improvement. He had the 1A2 phone and speaker. I never noticed before on those phones how the lights blinked. Here's the clip:
Jeff, that's very perceptive of you to notice. I often watch old movies and TV shows to see the modular cords in 1950's stories, to watch the incorrect lamp cadences, listen for incorrect ringing cadences, and to listen to the "ding-ding" coin deposit sounds on single-slot phones.

The lamps on that ITT or SC 2564 are being flashed by a non-standard piece of equipment, (probably an automotive turn signal flasher, or equivalent, or possibly even a stagehand doing it manually.)

Lamps on traditional 1A2 systems can be in one of 5 states:

Line idle, lamp OFF.

Line in use, lamp STEADY.

On an incoming call, the lamps FLASH at 60 IPM. A half-second on and a half-second off.

When the line is on hold, the lamps WINK at 120 IPM.

When the line is on "I-HOLD" (pronounced EYE-HOLD) the lamps FLUTTER. (Flutter is provided by a 408-series or 430-series KTU, and sets are wired especially for the I-HOLD feature.)

The lamps on the TV clip are doing "none of the above." Good catch!
Posted By: justbill Re: ITT 501C Intercom - 09/18/07 05:40 PM
Well not knowing if the system is the same as a Bell Key system I'm limited in what I can advise. Doesn't sound to me like you have and voltage going into the card to supply voltage to the buzzers. I've never used that card so couldn't tell you where the input would be. I'll bet Ed knows.
Posted By: EV607797 Re: ITT 501C Intercom - 09/18/07 05:46 PM
Matt:

Yes, there is an input option for the buzzer voltage, but I can't remember for the life of me if it's a jumper on the card or if it's a physical wire strap. If I were you, I'd clip onto digit 0 with one end of a continuity tester and touch the other lead to the various other clips in the general area of the intercom wiring (one at a time). The numbered clips down the lower right side of the block present the various system voltages and I am pretty sure one of them is your buzzer input. Keep dialing 0 over and over again and watch your continuity tester, each time moving to another clip. When it lights during the buzz cycle, then you found the input. Then, stay in that same area of the block and seek out the 10 volt AC power (note that you can always use the intercom's "L" terminal for your power). Strap a jumper between the two clips and you should be good to go.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/18/07 05:56 PM
Ed -

Thanks much, I'll do just that. Also, another contact pointed me to the holy grail for the KSU:

Edit by Bill: I know this is an old system, but board policy is to not post links to manual sites. Thanks

So now I also have the installation/service manual for the KSU, something I've been wanting for a long time.


PS:

Looks like it's a good thing I didn't mess with the jumper(s) on the intercom card. It switches the buzzer outputs from 10 to 105 volts.
Thanks again, will post back soon with results.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/18/07 07:18 PM
Ooops sorry aabout that.... didn't know.
Posted By: jeffmoss26 Re: ITT 501C Intercom - 09/18/07 07:34 PM
thanks for the info about those lights smile
Posted By: Matt1964 Re: ITT 501C Intercom - 09/18/07 10:04 PM
Well, I'm about to call this experiment a failure... perhaps the card is bad. Ed - reading through your last post, it sounds basically like the card needs to be fed the power it will pass on to the buzzers. This appears to be selectable from either 10v or 18v.

The manual says to run a jumper from row 28, terminal 6 to row 35, terminal 6 for 18v. Or to run a jumper from row 1, terminal 5 to row 35, terminal 6 for 10v.

Then another jumper from row 27, terminal 6, to any AG terminal.

I did this (which I think accomplishes what you conveyed), and still no volts at any of the signal outputs when pressing any of the keypad buttons.

I do measure 18v at R28 - T6, and 10v at R1 - T5, using LG for a ground, so I know the power is going in.

I'm going to go study the manual again, perhaps there is a jumper I have set improperly.
Posted By: Silversam Re: ITT 501C Intercom - 09/19/07 05:24 AM
Matt -

Good luck with the system. I don't know how much luck you'll have finding a replacement for the Intercom card - it was a fairly late arrival. I'm pretty sure I have some Teltone or Melco Intercoms buried in the basement. In fact I'm pretty sure I have a C-10 or C-19 there (Combination Tone & Rotary). These were stand alone units about the size of a paperback that were designed to work with 1A2 systems. If you're interested, PM me. Assuming one of them still works (which I'm sure they do - they were built to withstand Armageddon) you can have it for the cost of shipping.

Always glad to help out an enthusiast.


Sam
Posted By: Matt1964 Re: ITT 501C Intercom - 09/19/07 07:07 AM
Sam -

Cool - that's a very kind offer; I think I'll take you up on it. Actually I think I saw one of the units you mentioned on Ebay the other day, and am in conversations the seller of it as well, looking for more troubleshooting info on this issue.

Again - thanks - do you have a paypal account? If so, I'll transfer the $ as soon as you can get me the amount due.

Thanks -
Matt

Thanks
Matt
Posted By: Silversam Re: ITT 501C Intercom - 09/19/07 07:47 AM
Matt -

Send me an address. I'll dig up the unit and ship it out.

Sam
Posted By: Matt1964 Re: ITT 501C Intercom - 09/19/07 06:29 PM
OK,

Last post about this until I get the intercom unit from Sam (Thanks, Sam!).

I found another manual for my KSU, which had some slightly more specific strapping options. I followed them, and now here is what happens:

I hooked a voltmeter between R48/T5 and each signal output. I didn't see anything on 1, 2 or 3, but when I got to 4, the meter shows approx 18.5 volts when 4 is pushed. Also when 3 is pushed. Thinking maybe I had a keyset that was "out of tune" I hooked up a rotary. Same thing happened when dialing 3 or 4.

But no matter, I thought... I don't really mind if 2 buttons will signal 1 station; at this point I have only 2 keysets installed.

But, of course, I don't get off that easy. When I hook a buzzer to the terminals, I get nothing; almost as if there isn't enough currrent to drive the buzzer. Leaving the voltmeter in parallel with the buzzer shows zero when 4 is pressed.

Hooking the buzzer directly between LG and R28/T6 gets a very definite buzz, so there's nothing wrong with them. I have some buzzers with red leads, some with blue. Both colors seem to work OK at 18v.

So now I'm almost positive it's got to be a bad card. Thought I'd throw this out there for any possible comments though.

Thanks everyone, your help/comments are much appreciated!

- Matt
Posted By: EV607797 Re: ITT 501C Intercom - 09/19/07 07:50 PM
Matt:

The buzzers with red leads are for 18 volts; the ones with blue leads are for 10. Obviously, the life span of the 10 volt buzzers will be shortened if used with 18 volts.

The relays on the card form a matrix, almost the same matrix formed by a DTMF dial. For each digit dialed, a different combination of relays are activated. That's probably why you see something from two different digits when you are testing. You should see two separate relays operate for any digit dialed. The fact that you are getting the same response leads me to believe that the card is not bad.

It's not possible for an "out of tune" dial to cause the problem that you are having. If half of a DTMF digit isn't produced, then nothing will register.

You are very, very close to solving this. I am sure that the whole problem revolves around your input terminal for the 10 volts. I'll do my best to look around tomorrow and see if I can get you some more definitive information tomorrow.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/20/07 05:55 AM
Thanks Ed -

I can send you a link to show you exactly how I have the 66 block strapped, if that will help ya any.
Posted By: EV607797 Re: ITT 501C Intercom - 09/20/07 07:59 AM
Sure, send it on. I'll be happy to take a look for you.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/20/07 09:03 AM
Thanks Ed -

I PM'd you, as I wasn't sure if posting a page from a manual is against forum etiquette.

Thanks!
Matt
Posted By: EV607797 Re: ITT 501C Intercom - 09/20/07 09:04 AM
Matt:

I've done a little more research. On the intercom card itself, check the jumpers on TC1 and TC2. These are near the edge connector. These should both be in the "B to C" positions for buzzers. TC1 affects the even-numbered stations and TC2 affects the odd-numbered ones. Both should be set the same way.

For 10 volt buzzers, run a single jumper from row 1, terminal 5 to row 35, terminal 6.

For 18 volt buzzers, run a single jumper from row 28, terminal 6 to row 35, terminal 6.

Note that row 35, terminal 6 is the buzzer voltage input to the intercom card. Do not install both jumpers.

Lastly, your card may utilize two-digit dialing, meaning that the dial codes are 10-19 instead of single-digits.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/20/07 09:32 AM
Ed -

Yep, both are in B-C. I've also tried Jumper W in and out, no difference.

I'm currently using the 18v strapping; I've also tried the 10v to no avail. I've never hooked them both up, I imagine that would cause the magic smoke to get out.

I've also tried the 2 digit dialing - i.e. 14 for station 4. When doing this, it presents 18v at station 4 for 1-2 secs, just as only pressing "4" does. The manual says somewhere this capability is there to support up to 20 stations.

I think the main problem right now is I seem to have the voltage required, just not the current (at least at the signal output - if I hook the buzzer to the 18v term on the 66 block, it buzzes, so I've ruled out the power supply as a problem).

For a laugh I even tried one of the 10v line bulbs instead of the buzzer; it won't even drive that.

Oh well, if nothing else I'm learning a heck of a lot about 1A2.
Posted By: EV607797 Re: ITT 501C Intercom - 09/20/07 10:38 AM
It surely seems as if the other lead from your buzzers isn't reaching a ground connection.

Jumper W is removed if the touch tone adapter card is used and should be removed completely. Jumpers X,Y and Z are for call announce intercom via speakers built-in to the phones. All three of these jumpers are likely not the problem.

The only other straps that I can think of that might help are as follows:

AG: Strap row 27, terminal 2 to row 27, terminal 6. This will place a ground on rows 46 and 48 for lamp and signal grounds used by the intercom.

RG: Strap row 32, terminal 6 to row 34, terminal 6. This ties the ring generator's ground to the other grounds in the system.

One last effort might be to try substituting 10 volts AC for the 105 volts AC input to the intercom card. To do this, connect a strap from row 1, terminal 5 to row 34, terminal 6. Remove any other straps associated with these terminals. Then, on the intercom card, move the jumpers on TC1 and TC2 to positions A and B instead of B and C.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/20/07 11:31 AM
Ed -

I had a jumper from row 27, terminal 2 to row 27, terminal 6, so I was covered there.

I added one from row 32 T6 to row 34, T6.

Still no buzz.

Last night I read that AG needs to also be tied to the incoming ground connection, so I also have a jumper from AG to earth.

Going to try the last suggestion now.
Posted By: justbill Re: ITT 501C Intercom - 09/20/07 11:46 AM
Bingo! No earth ground 1A2 does all kinds of funny things. Ground the grounding lug to earth, water pipe (if not plastic).
Posted By: Matt1964 Re: ITT 501C Intercom - 09/20/07 11:51 AM
Well, no joy in mudville.

The only difference is that I now read 10v across sig term 4 and ground vs. the 18 that was there.

frown

Looks like it's going to be Sam to the rescue...! Although I am on your side of the fence with this card... my gut keeps telling me that something is missing that is unrelated to the card; but I've practically memorized the manual; combining this with all the suggestions you and others have made makes me think there can't possibly be any more configuring to do. The card doesn't have any obvious signs of damage (i.e. burnt resitors or leaking capacitors); and as I've said, it does click when pressing the keyset buttons (in my mind if a relay is clicking, the card is good; I would think all the IC's and associated circuitry are for decoding the signal from the keyset, and the relays do the work of passing the voltage on to the option punchdowns).

I bought the KSU on ebay about 2 years ago, it came with 5 line cards and this intercom card. I pulled the intercom card and it's been sitting on a shelf until this past week; so I have no way of knowing it's particular history. It's just that they seemed to build these things so rock solid that I'm hesitant to blame a card.

I guess my next step could be to pull the back off the KSU, and examine the backplane wiring. That's going to be a lot of work though.... I have the thing mounted pretty securely and I'm also not real keen on the idea of pulling my keysets off (I wire directly to the unit).

Or maybe some of the contacts in the option slot aren't making good contact with the board. One thing I havn't done is to clean them with an alhohol pad; maybe I'll try that.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/20/07 11:55 AM
Quote
Originally posted by justbill:
Bingo! No earth ground 1A2 does all kinds of funny things. Ground the grounding lug to earth, water pipe (if not plastic).
OK, I'll go try that now.
Posted By: EV607797 Re: ITT 501C Intercom - 09/20/07 12:00 PM
I wouldn't waste too much time with examining the backplane. True, it's possible that a wire wrap connection may have broken, but I've never seen that happen on a 601. Then again, who knows what may have happened in shipping? That was one of the reasons for my last suggestion with reversing the ring voltage vs: 10 volt signaling.

I doubt that it's contacts either. Those card contacts are huge, so there's little likelihood that they aren't at least making partial contact. True, a relay contact could be bad. Since it's a matrix of relays, all it takes is one to mess up everything.

I guess it's best to go ahead and wait for the unit that Sam is sending. I hate to give up since I've never seen one of these things fail, but there is a first time for everything. Maybe that's why it was sold on e-bay!
Posted By: Matt1964 Re: ITT 501C Intercom - 09/20/07 12:09 PM
Well, I tied from the ground screw on the power supply card to a cold water pipe....

Still nothing.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/20/07 12:15 PM
Quote
Originally posted by ev607797:
I wouldn't waste too much time with examining the backplane. True, it's possible that a wire wrap connection may have broken, but I've never seen that happen on a 601. Then again, who knows what may have happened in shipping? That was one of the reasons for my last suggestion with reversing the ring voltage vs: 10 volt signaling.

I doubt that it's contacts either. Those card contacts are huge, so there's little likelihood that they aren't at least making partial contact. True, a relay contact could be bad. Since it's a matrix of relays, all it takes is one to mess up everything.

I guess it's best to go ahead and wait for the unit that Sam is sending. I hate to give up since I've never seen one of these things fail, but there is a first time for everything. Maybe that's why it was sold on e-bay!
Yeah, I have to agree. We gave it everything we had... the only other thing I can think of is if there is another home enthusiast with this setup, I could ship them the card and see if it behaves or not. But that's a bit of overkill, I'm Sure Sam's card will do the trick.

Thanks for all the tips everyone! I'll post back after I install Sam's card.
Posted By: EV607797 Re: ITT 501C Intercom - 09/20/07 12:20 PM
Oh, we have a whole new project ahead. You aren't receiving a card from Sam; it's an entirely separate unit, so we'll be back to "row this and terminal that" for your power connections!
Posted By: Matt1964 Re: ITT 501C Intercom - 09/20/07 12:25 PM
Ya know - I was just about to go edit my post from "card" to "box"....!

lol.... can't wait for it to get here.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/22/07 05:00 PM
Sam, Ed -

OK - the magic box got here today (Thanks again, Sam)! But before I get to that, a short story to let you know a little more about the keysets I have as well as how my luck usually runs.

Some weeks ago, I decided I was tired of the keypad buttons on my red 2565 "miskeying".... I bought it on Ebay, and even though I'm a smoker... upon opening the box nearly got knocked over from what sort of resembled a telephone but smelled more like an ashtray that hadn't been emptied in 30 years. So I cleaned it up, but the buttons have always been a pain... if you press them at the wrong angle, you don't get the right tone. So I decided to tear it apart, get the buttons out, and soak all the nicotine out/off of 'em.

Well, it came apart a lot easier than it went back together, but I did my best and was pretty sure it would work. Hooked it all back up.... non functional. Checked, rechecked, checked, checked and then checked all the connections again. Took it apart again, ran a couple continuity checks, put it back together, hooked it all back up... still didn't work.

So today I made a post out in the wanted section for a new/used keypad, and a friendly member told me it's possible to use the keypad from a 2500 in a 2565. So I took out they keypad from a spare 2500 I had, and hooked it up... it didn't work either... at first. Then comparing my different series of notes on removing the leads from a 2500, 2565, as well as looking at another 2565 I have... I noticed that I had gotten the blue and black leads reversed on the "whatever you call the thing in the phone" that all the wires hook to (station block)? Swapped them back to where they should be... and viola, the 2500 pad worked great. Then I decided maybe I hadn't broken the 2565 pad, so I took off the 2500 pad and put the original back in. And it also worked great. I don't know how I missed the blue and black reversal after so many checks. I think my mistake was using B and/or BK in my notes to denote black when I wrote them, and then interpreting B as blue when I read them.

Anyway, feeling quite proud of myself, as well as getting instant help from this site once again (thanks, Arthur P. Bloom!), I mounted a buzzer in it, put the cover back on, and sat back, happy in the knowledge that I now have 2 WE 2565HK keysets that are fully functional and clean, one red, one white. For some reason I prefer the WE keysets to the ITT ones (of which I have several); they just seem sturdier. And so then I placed the red keyset on my desk, sat back, still patting myself on the back.... look at the phone... something isn't right.. and noticed.... I'd installed the the * and # keys in reverse. I'm not tempted to take the keypad apart again, so for now, I'm just considering it a highly customized model.

This is a small example of the pattern my life usually follows.

So anyway - I have the keysets in place, and 10v buzzers (blue leads) in each, hooked to the yellow/green pair.

Ed, I was browsing another thread where you were helping someone hook up their intercom box to a 1A2:

https://www.sundance-communications.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=35;t=000007;p=0

Here's what I've done so far:

1) Connected AG and AB from the KSU to the intercom. I also measured AB and AG and see about 24.5 VDC there.

2) Connected the black/green pair from both stations to the tip/ring of the intercom.

3) Connected the audible signal supply from the intercom to the 10v AC terminal on the KSU.

4) Connected the yellow/green pair from one keyset to the B0/R0 outputs of the intercom. I want to get one station buzzing before hooking up the other.

Now this is where I'm stuck. In your other post, you mention that there should be BB and BG terminals in the KSU to hook to the corresponding terminals on the intercom - but I don't see 'em on the KSU.

Also you mention running a single wire from the intercom's LB terminal to the KSU's LB terminal - I don't see this one on the KSU, or the intercom.

I'm sure the 'B' battery outputs are on the KSU somewhere; I'll go back to the manual and look for references for a -20 to -28 unfiltered DC source.

Gotta go walk the dog, will be back shortly. I'm hoping you guys lead a life about as exciting as mine and maybe browse this forum tonight.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/22/07 06:15 PM
Well, still no luck findding B battery. I'm not so sure it existsnow; looking at the manual for the power supply it says it provides:

1) Regulated -24vdc for intercom and line talk battery and power for logic circuits and relays

2) 18 vac for buzzers

3) 10 vac for lamps

And that's it.... should I just tie the intercom's AB and BB together onto the KSU AB?
Posted By: EV607797 Re: ITT 501C Intercom - 09/22/07 06:28 PM
Don't worry about locating a formal "B" battery in the 601A; just use the AB terminal to feed both AB and BB on the intercom unit. The current draw from an intercom unit will have zero impact upon the B battery supply.

A ground is a ground is a ground now that you have the jumpers in place that we discussed earlier, so you should be fine there.

"LB" is just the acronym for "Lamp Battery", which is 10 volts AC. Use the same source for your buzzer supply as your "LB".
Posted By: Matt1964 Re: ITT 501C Intercom - 09/22/07 06:40 PM
OK,

Will do - just had some unexpected company show up, so I'll post back later.

Thx
Matt
Posted By: Matt1964 Re: ITT 501C Intercom - 09/22/07 09:59 PM
Success! I have buzzers. One of my phones lights the hold button when it gets buzzed, the other doesn't I havn't decided if I like it or not yet.

One question - there is a slight hum on the intercom line; is this normal?

I really like the "ringing" you get on the receiver when buzzing another station.... very cool.

Thanks everyone -

Matt
Posted By: Matt1964 Re: ITT 501C Intercom - 09/22/07 11:42 PM
Reading through other posts:

https://www.sundance-communications.com/cgi-bin/ultimatebb.cgi?/ubb/get_topic/f/13/t/000488/p/1.html

it sounds like maybe I'll need to put in a 1000uf electrolytic filtering capacitor; I suppose across AB and AG (I say I suppose because I'm wondering if it should actually go across Tip and Ring).

I think the hum is caused by the fact I'm using the AB for both AB and BB. When using my old intercom card, there was no hum, so I don't think there is necessarily anything wrong with the power supply.

I'm thinking of going up to radio shack tomorrow to look for such a cap. I'm guessing it will need to be 24v or the next higher value available.

Thoughts?

Thx
Matt
Posted By: Lightning horse Re: ITT 501C Intercom - 09/23/07 06:19 AM
The cap shoud go across AB and AG. Across T and R you would 'filter' the audio out! Try for at least 35 Volts, 50 even better. You may be overloading the 'A' battery supply, be careful. ITT601 power supplies are not nearly as forgiving as as the big grey 1A2 power supplies from Elgin or whoever. That little regulator card is small in size AND capacity. John C. (Not Garand)
Posted By: Silversam Re: ITT 501C Intercom - 09/23/07 06:25 AM
Matt -

On most KV sets the Y/G pair is wired to the hold lamp. Of course many sets don't have a lamp installed at that spot so not all of them will light <G>.

Some sets allowed the use of a "phantom" 6th button - a "All Buttons Up" Itercom. If all your keys were up you went off hook and got T/R off the Y/Blue pair and lamp off the Y/G pair. Buzzing on the Y/O. Stromberg Carlson sets came standard like this and some WE sets (but I think you had to also pull up one of the hook switch buttons to activate it on a WEco set)

I always used Y/O for buzzers(except on Northern Electric/Telecom Logic sets in which case it was Y/Brown.

Confused enough?


Glad everything works and that you've got Intercom.

You can also add ICM only phones using 2500 phones. Connect G/R to T/R and B/Y to the buzzing pairs, then open the B/Y inside the set and connect a buzzer.

Sam
Posted By: Matt1964 Re: ITT 501C Intercom - 09/23/07 10:09 AM
Thanks Sam, John -

It's good to know I can make an intercom out of a 2500 - that will come in handy some day. ANd thanks for the cap info John.... !

Matt
Posted By: Matt1964 Re: ITT 501C Intercom - 09/23/07 12:17 PM
Well, I put the cap in. (1000uf, 35v) I bought 2, cause I figured I'd get it wrong at least once. The first time I hooked + to AB, and - to AG. Cap started to get hot, unplug NOW.

Went for a walk, realized (duh) AB is - (for some reason I just can't get that straight in my mind). Put in a new cap, it's not overheating though there is still some buzz. Not as much, but some. I can live with it.

And thus the intercom chapter is closed.

Stay tuned for the next project: MOH.

THANKS EVERYONE.

- Matt
Posted By: Silversam Re: ITT 501C Intercom - 09/23/07 12:39 PM
Matt -

Do you have one or two sources of -24VDC on that beast? If you have two hook one up for A and the other for B.

Also - lift all the wiring off the power supply -24v, then take a butt set and go a cross it. If it still hums coming out of the supply, then that's it. If it doesn't, start attaching the connections one at a time and see which one puts on the hum. Trace that back and see - might be a defective 400 card or......?

Also that ICM I sent out will work Tone or Rotary - so if you dig up some old sets, it'll still work.

Sam
Posted By: Lightning horse Re: ITT 501C Intercom - 09/23/07 12:57 PM
Matt, if you are using a non-601 intercom, You may be just plain overloading the 601's power supply. That will cause hum and consider it a warning from the 601 power supply! John C. (Not Garand)
Posted By: Matt1964 Re: ITT 501C Intercom - 09/23/07 02:07 PM
Quote
Originally posted by Silversam:
Matt -

Do you have one or two sources of -24VDC on that beast? If you have two hook one up for A and the other for B.

Also - lift all the wiring off the power supply -24v, then take a butt set and go a cross it. If it still hums coming out of the supply, then that's it. If it doesn't, start attaching the connections one at a time and see which one puts on the hum. Trace that back and see - might be a defective 400 card or......?

Also that ICM I sent out will work Tone or Rotary - so if you dig up some old sets, it'll still work.

Sam
Sam -

Pretty sure there is just one 24v output. See my PM for PS specs.

I'm thinking I have a ground issue or something. AG is tied to the power supply grounding screw as per instructions, and basically every ground (AG, LG, etc) is really the same point now. I tried disconnecting all keysets (2) and swapped in a third one (an ITT) in favor of the 2 WE keysets - same buzz. Then I disconnected the lamp feeds to the intercom, and the 18v station signal input... same buzz. My next step will be to disconnect everything from AB and AG; possibly everything from the entire KSU, and see if I still have a buzz on AB/AG...... if not, then I'm guessing it's the intercom putting out the buzz, since it feeds tip and ring to the keysets.

It's really not that much of an annoyance...... but it would be nice if it were completely silent.

I do have an ITT rotary, so it's great to know it will work with both!

Thanks Much!

Matt
Posted By: Matt1964 Re: ITT 501C Intercom - 09/23/07 02:14 PM
Quote
Originally posted by Lightninghorse:
Matt, if you are using a non-601 intercom, You may be just plain overloading the 601's power supply. That will cause hum and consider it a warning from the 601 power supply! John C. (Not Garand)
Thanks John - I really hope that's not it.... as you can see from this thread, there has been a great gnashing of teeth any many, many attempts to get my old intercom card working. If I have to resort to finding a working intercom card for this unit.... I will be: frown

The one Sam sent me is very cool.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/23/07 03:05 PM
Well, I disconnected everything from Every AB/AG terminal on the KSU. I don't have a butt set, so I hooked a 2500 between AB and AG..... and got ...buzz.

So, I guess it is the power supply. But I almost think this is a result of the design of this KSU, as it doesn't have seperate filtered/and unfilterd (AB and BB) supplies. When I had my old intercom card in, there was no hum on the T&R terminals, so it's like they built some sort of filtering into the intercom card itself, since the KSU didn't provide it. Then again, I thought AB & AG were supposed to be the filtered ones... so I'm lost again.
Posted By: Silversam Re: ITT 501C Intercom - 09/23/07 04:06 PM
Matt -

Keep your eyes peeled on ebay for a power supply - or - whenever you go into an office buildings tel closets keep your eyes open for any abandoned ones. I can't speak for KC, but in NYC every 3rd closet in an old building has an abandoned (JUST MAKE SURE IT REALLY IS ABANDONED) power supply.


Sam
Posted By: Matt1964 Re: ITT 501C Intercom - 09/23/07 04:32 PM
OK - will do. I know there is the same KSU I have on ebay right now, no cards, or interrupter, but it has the PS and ring generator. Maybe I'll go throw a bid at it just for parts.

Thx!

Matt
Posted By: KLD Re: ITT 501C Intercom - 09/23/07 05:09 PM
Matt----just perusing this thread.....is this KSU really an ITT 601 shoebox? I still maintain one of these beasts.

:rolleyes:

I'n not far from you.....drop me a line and we'll see what we can do for you.

Edited to correct my inability to read the whole thread.......

Ed is on the button. Still, drop me a line....may have some of what you need.....or an ITT 512 full of goodies !!!!
Posted By: Matt1964 Re: ITT 501C Intercom - 09/23/07 05:35 PM
Cool! Thanks Ken!

Yep, it's a 601. And after the ordeal listed in this post... I know one heck of a lot more about it now then I did a week ago.

Where I'm really gonna need some help is mounting some 66 blocks and cross connecting over to the KSU. Right now I terminate on the KSU itself, but I can see this isn't gonna work for much longer. I've read about the blocks, but it makes my head spin.

In other news - I've gotten rid of the hum on the intercom line problem.

As I'd said, when I was using my old non functional intercom card, I did get clean voice capability, just no volts/amps to the signal output. So I went down, put the old intercom card back in, used it's Tip (or was it Ring)? I don't remember. Anyway, it had 24v on it. So I connected that to the A battery input on the intercom, and used my AB output from the KSU to drive the B battery on the intercom.

Now I've got buzzing, illuminated hold lamps on intercom use, and a clean, no hum intercom voice path. I don't see any issues with this, as there are no connections made anywhere now (other than the tip or ring) on the intercom section of the block. I guess I essentially made my own AB output.

Man, if I still drank, I'd go have a beer. Instead, I'll have to settle for walking the dog. smile
Posted By: KLD Re: ITT 501C Intercom - 09/23/07 07:51 PM
:thumb:

Matt, the 66 block is no big deal....especially if you have access to the ones that take up to six connections.

Then you use one cable from the KSU to the block. Makes for easy changes, less mess.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/23/07 08:15 PM
Well, If you ever plan on being out Lee's Summit way, I'll get all the materials together, maybe you could help me mount it all up so it looks professional and is up to spec. I think that's whats always amazed me about the wiring closets I've seen - didn't have a clue how they worked... but man, the professionalism in em was beyond words. Kinda like when I used to see the old knob and tube wiring in the basement of a house where it hadn't been hacked apart yet and turned into a fire just waiting to happen.

I think I could grasp the technical concepts behind it with some help, but I need someone to teach me the way to route the wires properly, around what I think they call 'mushrooms', down to the blocks, etc.

Dinner/Lunch/whatever you want to eat/drink at wherever you want to go is on me. Or if you want to be paid for your time/travel, that works too. Or both. Would be great to just spend some time chit chatting as we work, would love to hear some of the stories I'm sure you have to tell.

It's going to be a little while, I've got to round up some more amp. cables - right now I've only 2 keysets, but plan on going to 6.

I only have 2 CO lines, but want to wire each station for all 4 (5 is now intercom), so if I do get another line, I can punch it down in one place.

Thanks again,
Matt
Posted By: EV607797 Re: ITT 501C Intercom - 09/26/07 10:09 AM
Matt:

I don't know why I didn't think of this earlier, but I do have the intercom card and TT adapter in stock if you are interested in trying it out to do a sanity check.
Posted By: Matt1964 Re: ITT 501C Intercom - 09/26/07 04:40 PM
Ed -

That's OK. I really like the unit I got from Sam, it gives me a beep beep beep when I buzz another station. I'll let ya know if I ever wanna go complete stock someday. I'm 99% sure there are one or more bad relays on it; I noticed signal outputs 1, 2 and 3 ALWAYS have 10v on 'em, 4,5 and 6 get 10v when you press a button, and 0,7,8 and 9 never have any volts present. Still, the relays do click for each corresponding button pressed. I looked up the relays, and they go for around $29 a pop; so I won't be going down that road anytime soon (as in... this lifetime). Thanks for the offer though!

- Matt
Posted By: n4yqt Re: ITT 501C Intercom - 05/12/08 03:50 PM
© Sundance Business VOIP Telephone Help