malcolm@apple.com (08/29/89)
I was in LA over the weekend and I got a tour of a Pac Bell central office. Mind you this was not a normal office. Hookup charges were $1300 per line! (I didn't ask whether they charged for directory assistence :-). All calls were made by a craftsperson who made the appropriate connections on a little plug board. These were hardly your normal voice quality circuits. We were wondering around the top of Mt. Wilson (5500 feet or so) and found the Pac Bell microwave station. It was a rather warm night and behind a screen door there was a big black 30-40 year dude chomping on a cigar. We said hello and he invited us in to chat and see his toys. He had what looked like a couple of dozen microwave dishes (at 6 and 11Ghz) that were pointed around the valley. He seemed rather bored with the TV link he was monitoring. It was a live feed from the Laugh House up to Mt. Wilson and then back to some other company in Hollywood for a satellite up-link to a customer in NY. I guess they had rolled a truck up to the site of the video feed and just pointed the antenna in the right direction. We asked him how hard it was to get it pointed the right direction and he proudly said that he'd been doing this long enough (9 years) that he could get it pretty close just from the address. He said that there was about 5 degrees latitude in the pointing before the signal would be unusable. I got the impression that there were just transmitting raw video. He had the signal fed into a TV and it didn't look like they were even bothering to convert it into digital or any of the normal T-type transmission standards. The transmitters and receivers looked small (8" x 12") and homemade (maybe 10-20 years old.) I remember being surprised by the size of the transmitters. We had been looking at the TV antennas and seeing 8" feeds up the tower. We were expecting the same thing here. He was only using 1w to get anywhere in the basin! In retrospect it seems obvious since it is line of sight and he had fairly large antennas (2m?) The cost was pretty much dominated by the set up charges. The charges were per hop so even though JPL was less than 5 miles away they got charged twice the normal rate since it had to go to another mountain before making it up to the top of Mt. Wilson. It was pretty interesting. He was one of those really good I-know-how-to- make-this-equipment-work type of craftsperson that are such a joy to meet. He was all to happy to show us the raccoon that was always getting into his garbage and tell us about the Mt. Wilson astronomers. Definitely worth the trip. Malcolm