blasts from the pasts

[Opcom]

I'm reminded of some cool places I worked before. Usually there are not many RF related workplace tales or photos, but I think when it is not forbidden and involves electronics, it can be interesting.

The first one is a DSL MODEM engineering lab, now long gone as DSL is nothing special any more but a commodity.

I worked with throughput testing, BER, MODEM training optimization at long spans, noise, and TX/RX filters here. Eventually VDSL was worked with, making over 100Mb on a twisted pair.

Although the MODEMs handled digital signals, the end output signals were of course analog and that portion was very wideband, including some RF, and the amplifiers had to be extremely linear and very low distortion, just like modern transmitters.

Proper capacitor selection and attention to circuit balance was paramount. If a capacitor in a filter changes value over a half-cycle of a multi-carrier analog signal covering 20KHz to 2MHz, even a percent, it causes distortion and we were measuring that in customer-built prototype designs based on our reference designs. Also putting chip caps on network analyzers.

There was more than one time of amusement when a customer had his first boards fabbed up on the cheap, and the EMS (electronic manufacturing service, a contractor) thought to make a few extra pennies for itself by subbing the unmarked high-quality precision chip capacitors with cheap ones. 10nF is 10nF, right? Contractor saved 10 cents and we spent 10 hours fixing it. We learned to 'shotgun' the caps in the filters with correct ones and cut this to about an hour. If that fixed it, we just sent the boards back to the customer with a note which later became an application note. If the EMS got a chewing out later we never heard about it.

[w1vtp]

Very cool Patrick!  Brings brings back memories of my early days as an engineer in a microwave antenna range and the VERY OLD HP 1000 equipment.  Data storage was done on tape drives, the antenna measurement program was homebrewed in RTE OS format.  Commands were complicated command line format.  What a chore!  I remember when the heads crashed on the hard drive platters (they were removable with a handle on the top just as in the sci-fi movies).  What a scream the hard drive made as it died in a matter of seconds.  End of an era.

Meanwhile in another area, management was doing an evaluation on whether or not to save a whole room of data processing using the same HP 1000 system including those cool tape storage consoles like you see in some of those early sci-fi movies.  Anyone remember the RTE operating system?   Well, we got the system going after days of intense troubleshooting only to be told that they needed the rooms that the system (now working) was in so with heavy heard I dismantled everything and we stored the now corpses in some unoccupied office cubes.

The system did graduate to hard drives - 50 mb capacity that took up the space of a portable dishwasher.  I think the disks were HP model 7920's. This was 1970's computer technology - I'm glad I was able to oversee the transition from that system to still modern control computers that operate precision X, Y, Z axis stepper technologies that allow positioning scanners  to as close as plus/minus 0.002" within a cone of 25 feet by 10 feet by 11 feet - all computer controlled.  Oh yes, also we had a theta, phi axis computer controlled antenna mount that could position a 1000 lb antenna.  Now-a-days all data crunching is don't in the engineer's office over a data line to servers that are shared.  Even so, data crunching can take days to complete.

What a ride!!

Al

[flintstone mop]

Hows about the Xerox 914??

http://xerox914club.blogspot.com/

Or:

https://www.youtube.com/watch?v=9xZYcWsh8t0

This connects more to the computer thread

http://futurebots.com/cpu.htm

Musical Disk Drives

https://www.youtube.com/watch?v=ZFmC7hd1hno

ONE more

https://www.youtube.com/watch?v=DaVqewZYrNM

[WD8BIL]

Imsai 8080!

[Pete, WA2CWA]

Bell Telephone Laboratories was the coolest place to work for me. Lots of interesting people, lots of interesting projects, and lots of weird and cutting-edge stuff going on all the time.

http://www.beatriceco.com/bti/porticus/bell/images/history-%20bell_labs_large.png

A Bell Labs scientist studies a helium-neon laser to determine the relationship of power output to the length of the cavity, ca.1963-1964.

Even the water tower was cool:

[W6TOM]

 I remember the Imsai 8080, the manufacturing facility was a few miles from here and every time I drive by and look at the building I think what was there, well over 30 years ago.

[WA2TTP Steve]

Hi Al,

Your antenna range sounds like it was modern compared to where I worked in 1969. It was Wheeler Labs in Smithtown NY which was a subsidiary of Hazeltine in Greenlawn NY. We didn't have any computer equipment on the range. All the antenna plots went to XY plotters. All the rotors were mounted on the roof and could be configured, with the help of the building crane, to Az, Az-El and Az-El-Az. The last one is shown in the attached picture. That's me working on a scale model of an F4 which we were developing some flush mount communications antennas for. OHSA would have had a field day with this setup!

The range had a source building about a 1/4 mile away across a natural valley. It had transmitters from VHF to about 40 gig. All the measurement equipment was inside behind large picture windows so you could see what the rotor units where doing. Smashing the model into the roof wasn't an option!

Steve

[w1vtp]

Hows about the Xerox 914??

http://xerox914club.blogspot.com/

Or:

https://www.youtube.com/watch?v=9xZYcWsh8t0

This connects more to the computer thread

http://futurebots.com/cpu.htm

Musical Disk Drives

https://www.youtube.com/watch?v=ZFmC7hd1hno

ONE more

https://www.youtube.com/watch?v=DaVqewZYrNM

I think my good friend Herb, WB1DSW used the Zerox as the basis for a packet BBS many years ago.  I just looked up Herb.  His license just expired - gotta give him a call

Al

[WD8BIL]

I remember the Imsai 8080, the manufacturing facility was a few miles from here and every time I drive by and look at the building I think what was there, well over 30 years ago.

It took 2 hours to load in the lunar lander program then you can crash into the moon in 2 minutes!

[w1vtp]

Hi Al,

Your antenna range sounds like it was modern compared to where I worked in 1969. It was Wheeler Labs in Smithtown NY which was a subsidiary of Hazeltine in Greenlawn NY. We didn't have any computer equipment on the range. All the antenna plots went to XY plotters. All the rotors were mounted on the roof and could be configured, with the help of the building crane, to Az, Az-El and Az-El-Az. The last one is shown in the attached picture. That's me working on a scale model of an F4 which we were developing some flush mount communications antennas for. OHSA would have had a field day with this setup!

The range had a source building about a 1/4 mile away across a natural valley. It had transmitters from VHF to about 40 gig. All the measurement equipment was inside behind large picture windows so you could see what the rotor units where doing. Smashing the model into the roof wasn't an option!

Steve

Steve

Yes. there was a lot of flexibility with that homebrewed range.  However, training was intense as everything was done on a command line.  That picture you put up looks like a RCS (Radar Cross Section) setup.  We can not do that here in Massachusetts.  Our second generation setup could go from < 1GHz up to 110 GHz.  We lost that W band capability due to additional expense needed.  We still could do up to 50 GHz in both the Far Field range and the Near Field range.

Al

[w8khk]

Very cool Patrick!  Brings brings back memories of my early days as an engineer in a microwave antenna range and the VERY OLD HP 1000 equipment.  Data storage was done on tape drives, the antenna measurement program was homebrewed in RTE OS format.  Commands were complicated command line format.  What a chore!  I remember when the heads crashed on the hard drive platters (they were removable with a handle on the top just as in the sci-fi movies).  What a scream the hard drive made as it died in a matter of seconds.  End of an era.

Meanwhile in another area, management was doing an evaluation on whether or not to save a whole room of data processing using the same HP 1000 system including those cool tape storage consoles like you see in some of those early sci-fi movies.  Anyone remember the RTE operating system?   Well, we got the system going after days of intense troubleshooting only to be told that they needed the rooms that the system (now working) was in so with heavy heard I dismantled everything and we stored the now corpses in some unoccupied office cubes.

The system did graduate to hard drives - 50 mb capacity that took up the space of a portable dishwasher.  I think the disks were HP model 7920's. This was 1970's computer technology - I'm glad I was able to oversee the transition from that system to still modern control computers that operate precision X, Y, Z axis stepper technologies that allow positioning scanners  to as close as plus/minus 0.002" within a cone of 25 feet by 10 feet by 11 feet - all computer controlled.  Oh yes, also we had a theta, phi axis computer controlled antenna mount that could position a 1000 lb antenna.  Now-a-days all data crunching is don't in the engineer's office over a data line to servers that are shared.  Even so, data crunching can take days to complete.

What a ride!!

Al

I serviced all that stuff at HP from 1977 until about 1988, then on to other projects at HP.

The printer is a 2680A Laser Page Printer, cost around 100k at the time. 

The disk drive is either a 7920A at 50MB, or a 7925A at 120MB.  They look identical.  I have used lots of components from scrapped drives of this type for ham radio projects.  The disk controller in the bottom had a power transformer perfect to light up the filaments of a pair of 4-1000As! 

The computer is one of the earliest HPIB-based 3000 series, a model 30, as evidenced by the 8 inch floppy disk used to load diagnostics. 

Brings back lots of memories, especially the 2 or 3 AM callouts to hospitals that used the systems to manage medication records.

[WA2TTP Steve]

Hi Al,
The project I was on was testing and developing cavity backed communication antennas in the 200-300 mhz range. The model was a 1:5 scale so our test frequencies and antennas were designed for 1.2 ghz for pattern testing. We were trying various locations on the plane and also various combinations of antennas. I worked on allot of interesting projects there but the recession in the late 60’s hit the company pretty hard resulting in many layoffs. I left about 2 months before the axe fell.

Steve

[WA2SQQ]

One of the neatest places I worked (and still work at) was at Panasonic. Until we moved out of the Secuacus, NJ facility 2 years ago our labs, used for testing of consumer products, were one of a very few areas that dated back to the early 70’s when the facility was built.

We had an undocumented storage area that was a time capsule where product reference samples were stored (and forgotten about). Two years ago as we prepared to move to our new building we started cleaning that area out. I found brand new high end Technics products that are today worth twice their original price. That SL1200 turntable with the stone base and moving coil cartridge that I could never afford is now mine!  Reel to reel units from floor to ceiling that surprisingly no one wanted. Also found some of the old cellular bag phones in addition to some competitive “flip phones” that resemble star trek communicators.  Cases of tri-axial car audio speakers that literally dry rotted away over the years, packaged with some Technics DCC (Digital Compact Cassette) mobile audio players.  It was literally Christmas in July that wound up occupying half of my garage. It hurt to see so much of the company’s history get smashed and thrown into the dumpster! I regret not photographing it as we sorted through it all.

[w1vtp]

SQQ:  Yeah, went through the same experience.  Our dept, in the so-called "high bay" area, had 20' ceilings which occupied that whole floor.  We had to make room for a newbie dept called "Mission Innovation" so I was in charge of junking some pretty historical computer stuff along with some prototype antenna stuff that no one wanted to claim to make room.  Later on, once the newbie dept was established, I inherited one of the "high rent" glassed-in offices.  A fitting end of a 50 year career, if I can say so.  Very gratifying from my point of view.

TTP:  Too bad you couldn't have stuck around and done some serious upgrades on that facility.  Ah well...

Al