Detailed info sought on BSP.... 518-114-110 Page #12

[Babybearjs]

I don't know if anyone can help, but at least I'll try. I'm looking for more details on BSP #518-114-110, Page 12. I'm looking for original cap and resistor values. I have 2 207C ICM Modules, and I just switched them out. the newer, dated 11/1970 has a poor delay time on the buzzer circuit Vs. my older one. does anyone know if the TCI library has more info on this, or just what I already have? any help would be appreciated...

[paul-f]

I don't know if anyone can help, but at least I'll try. I'm looking for more details on BSP #518-114-110, Page 12. I'm looking for original cap and resistor values. I have 2 207C ICM Modules, and I just switched them out. the newer, dated 11/1970 has a poor delay time on the buzzer circuit Vs. my older one. does anyone know if the TCI library has more info on this, or just what I already have? any help would be appreciated...

Can you read the values off the parts?

The BSP gives SD references in secition 1.03 (below). The second one is in the TCI Library, but doesn't have the parts you seek. Try posting a request to the TCI Listserv for the other one and more info.

[TelePlay]

Looking at the BSP, it does seem it is a field level document, not a refurb, repair or factory build spec document. No values provided in that document. Has to be a build list somewhere, maybe.

[paul-f]

Looking at the BSP, it does seem it is a field level document, not a refurb, repair or factory build spec document. No values provided in that document. Has to be a build list somewhere, maybe.

If you find any let us know!

Collectors have been looking for engineering- or factory-level detailed documentation for as long as I can remember -- without success.

About the best docs found to date are the CDs and SDs.

[HarrySmith]

Build list? Is there such a thing for phones?? I have heard (or read) interesting discussions about factory documentation. Would be great stuff to have.

I remember finding the build list for cars under seats and in trunks. Interesting stuff!

I have a story to tell about a build sheet but it's not proper here. I will open an off topic topic.

[TelePlay]

Build list? Is there such a thing for phones?? I have heard (or read) interesting discussions about factory documentation. Would be great stuff to have.

I remember finding the build list for cars under seats and in trunks. Interesting stuff!

I have a story to tell about a build sheet but it's not proper here. I will open an off topic topic.

Somewhere some engineer who drew the diagram for production had to specify the values for all of the components for purchasing and production.

Fortunately, most radio schematics have the resistor and capacitor value on the "wiring diagrams." Other than for field replaceable parts (capacitors in 302s for example), the properties of complex telephone wiring diagrams don't have them. Old radio schematics have the wiring diagram with numbered components and then a parts list - I suppose because radios were serviced, not junked back then.

These complex telephone systems were probably pull, replace and send bad unit back to a refurb facility, as PC boards are today except today the pulled board is junked.

I wonder what happened to all those documents buried away in some deep, dark vault at a nondescript WE or AE facility.

[Babybearjs]

I found the information that I was looking for through the library, but..... it doesn't address the issue I'm having other then telling me the buzz duration is set at 1.5 Sec. but it doesn't tell me any thing else. the information on the 6A phone system is limited and very, very general... and I was hoping for more detailed info.... does anyone know if there were any repair guides published for these things.... it looks like I'm going to have to switch out the 207 again and put the older one back in.... at least it works right..... and then try to repair the old one.... from what I was reading, its the caps that are bad.... and I'm pretty sure its the KS-16171-L1 cap that's going to be replaced.... I found the info through SD-69286-01-C1. its a whole lot of reading....

[poplar1]

The repair specs used at the Western Electric Service Centers (repair shops) are the "Bell System Repair Specifications" (BSRS). These were not the same as the Bell System Practices (BSPs). So far, the BSRS have been a "no show."

Did ITT-Kellogg or Automatic Electric manufacture the same or equivalent selector? At least, the ITT and  GTE shop manuals are still around.

Can you look at the capacitors on both of your 207s and compare them? Or possibly a slow release relay?

[RB]

For the time you are spending thinking about it,
you could have replaced the cap, and been on your way.
Old caps always leak, and become less than originally built.
ANY piece of electronic equipment that has some operating time on it,
WILL have bad caps.
Caps are cheap, just replace them, "with properly rated substitute".
I will add disclaimer here...I do not know what you are working on...
It appears that it contains a resistor/cap drain timer? the part you are having trouble with.
even if you put in a cap that is different, it will still work,
it will only change the hang time of the drain circuit.
experiment if you need to, until you are satisfied with the result.

[kb3pxr]

For the time you are spending thinking about it,
you could have replaced the cap, and been on your way.
Old caps always leak, and become less than originally built.
ANY piece of electronic equipment that has some operating time on it,
WILL have bad caps.
Caps are cheap, just replace them, "with properly rated substitute".
I will add disclaimer here...I do not know what you are working on...
It appears that it contains a resistor/cap drain timer? the part you are having trouble with.
even if you put in a cap that is different, it will still work,
it will only change the hang time of the drain circuit.
experiment if you need to, until you are satisfied with the result.

Not just the caps, but also check the resistors too. Carbon comp resistors drift up (higher resistance) in value over time. Replace with a modern resistor of suitable rating and it will likely never be a problem again.

[Babybearjs]

well, after reading the info I found, I figured out the cap could be replaced, its just a matter of taking the unit apart and replacing the cap.... thank you for all the help....