[GreenKeys] M28 Label

[w8roi]

Re: 99nn numbers

When I got my 101A DataSet, I was told by a telco guy that my central office had a phone number which would send a particular tone at zero db as it left the office. This allowed techs to determine gain/loss settings on Hybrid systems to have proper tone levels for incoming and outgoing tones.

I think it was 9997 for the tone. 
(There was also a “silent termination” number that was just that:  NOTHING but a proper impedance and silence on the line.)

Since we lived just a few blocks from that office it was important. 

I called that number, with my trusty multi-meter set for db. 

It showed a number and from a chart I was able to set my outgoing tone so as to not overload my central office and attract unwanted notice.  I was also able to set jumpers so that the input to the data set was right. 

This is all “off the top of my head”, from 1969 when I got the data set.   A group in metro Detroit had these data sets and an unofficial network in service. 

Michigan Bell was a bit annoyed since they could not use the “no foreign attachments” rule for the data sets.  They were designed and built by Western Electric and met all specs. 

The group lasted for several years and a few were threatenened with termination of service, but it never happened. 

Somewhere in a file cabinet I have one or two of the lists of participants, with phone numbers, answer back sequences, etc. Those were fun times for me. 

Ralph - W8ROI 

- - - - - - - -

Sent from my iPhone

> On Jul 30, 2019, at 9:18 AM, Roy Morgan <k1lky68 at gmail.com> wrote:
> 
> Tom,
> 
> A long time ago I was membership person for our antique radio club (MAARC), and the newsletters had me as return address. We would include pictures of radio related ads from the 20’s and 30’s. 
> 
> One fellow wrote to me asking if I had a changed address for a company that had closed 40 years before. His letter to them had been returned. 
> 
> Roy sends.
> 
>> On Jul 29, 2019, at 9:32 PM, Thomas Tillson via GreenKeys <greenkeys at mailman.qth.net> wrote:
>> 
>> I have this on mine - I tried calling but no answer.  LOL
>> 
>> TT
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