David, This controversy sounds just like a situation I experienced in 1977. AT&T had designed the Bell 212A modem. The Bell operating were renting and installing them at customers sites. To installed them required 4 to 5 hours of technician time. These techs used Telecom Test Sets to make adjustments to a repeater on each line that had a 212A attached. During that time I was working for Vadic (later known as Racal-Vadic) Our chief scientist (J. Bingham) had designed and patented the Vadic VA-3400 (FDX 1200 bps modem) several years before and we did not require making adjustments to line to get maximum performance.
We were curious about why a repeater was required and why 212A lines needed adjusting. We disconnect the 212A's and used a spectrum analyzer to check the line. We discovered the repeaters were used to adjust the high end frequency response and to provide better group delay across the telco band. We used this knowledge as a marketing ploy against our competitors, AT&T. This caused a number of problems. AT&T was sure we had reverse engineered the 212A and were going to tell the world how it was designed. They threaten legal action (Their 212A patents were still pending). All of this just because we looked at the freqency response and group delay adjustments made to the line. Nothing ever came of the situation, but we were a bit worried for a time. Regards, Duane iiiii????+++ Nothing ever became of their threats, but it caused a bit worried at the time. Regards, Duane _________________________________ On Thu, 1 May 1997, David Drori wrote: > Haim Geva of Tadiran asks: > > "Hello everybody It's nice to see our product detailed description from > third body. How did > he got our equipment at his office?" > > Well I never! I thought my letter was clear; however, I'm sorry if I left > anything open to misunderstanding. > > Once again: The Tadiran equipment to which I was referring is a line > doubling apparatus that the telephone company (Bezeq) installs on the > subscriber's premises. The telephone company installed this apparatus in > our office when we requested an additional telephone line a couple of years > ago! Nothing more sinister than that! > > As you can see from my previous letter, the apparent on-hook DC resistance > presented by the Bezeq-installed equipment is given by myself as a result > of a measurement that I made on the telephone line. The only reason I > troubled to make this measurement is that -- while I was trying out > subscribers' equipment -- it appeared that the telephone line was behaving > in a way that I would not generally expect. Rest assured that I did not > tamper with the device itself, or seek further information from any other > source. > > I personally do not agree that my statement regarding the results of a DC > line measurement constitutes "a detailed description" of your product. > > I hope that this is now crystal clear. Incidentally, another of these > devices was also installed by Bezeq at my home address. Undoubtedly, many > Israelis have line doublers on their premises, all put there perfectly > innocently by Bezeq. > > I wish to make one further important point: the sole purpose for my > original message on this subject was to attempt to justify the requirements > stated in BAPT 223 ZV 5 and TBR 21 relating to the behavior of subscribers' > terminal equipment at low DC currents, because other TREG members have > asked about this. Naturally, in case this was not already clear, I was not > claiming that the Bezeq-installed Tadiran apparatus was in any way > defective. > > I need to mention that we have enjoyed a long and very happy relationship > with Tadiran in several fields, and it seems that my completely innocent > mention of Bezeq-supplied equipment that happened to be manufactured by > Tadiran, raised some eyebrows. > > It is truly amazing to see just how easy it can be to create unease, and I > do hope that this note puts to rest any concerns that you might have. > > If this response is fully understood, then it would be very much > appreciated if you will send a short note to that effect, to all the > recipients of your message. I am asking you to do this because I'm afraid > your message seems to imply improper behavior on my part, and I am > perfectly sure that this was not your intention. > > Warmest regards to you Haim, to Amos Maor, and to all our other good > friends at Tadiran. > > David Drori > > --------------------------------------------------------------------------- > ------------------ > Novarex Enterprises Ltd., > POB 2833, > Jerusalem 91028, > Israel. > Tel: +972 2 581 0995 > Fax: +972 2 581 3750 > Mobile: +972 5 067 8686 > E-mail: [email protected] > --------------------------------------------------------------------------- > ------------------ >
