That would be hard to do at HF or VHF since you can't focus the RF
into a tight beam at those frequencies, compared to a couple degrees or
less at microwave frequencies. :)
If you must, but I just like to trade war stories about equipment
that would make newbie techs retch or fill their drawers when they see
the size and the hazards involved. The sheer look of terror on their
faces is priceless! Like me standing on the HV power supply inside a
VHF high band TV transmitter so I can adjust the interstage coupling
while the station is on the air. The end of the cabinet was removed,
since it didn't have any interlocks, and i was standing on one of the
transformers. It was either do it that way, or spend days removing the
rear door, making a small adjustment, replacing the rear door then
firing it up to find it still had too much ripple in the video
bandwidth, shutting it down and starting over. :)
I've worked with a lot of high voltage power but there on the island
the highest power runs were 4160 3 phase. The superintendent I was
working with borrowed a wooden hot stick from the power plant crew.
Lucky thing he was wearing the high voltage glove set. I think his
hard hat popped off when his hair stood on end while we were plugging
in the transformers. Did you know that a slightly damp hot stick will
conduct electricity? Ya know shortcuts can be dangerous. This particular
guy got himself killed a few years later when he fell down a shaft in
Cairo while trying to change a lamp in a fixture on a big sewer project.
He decided he didn't need that pesky safety harness.
As far as that big radar goes, I know I wasn't hearing things. It will
operate in CW mode at VHF and UHF frequencies. Here's a link and I still
wish I had gotten a closer look at that thing.
RADAR works by timing the reflections. They are using 'CW' to imply
that there is no complex modulation.
Have you ever read the 'RADAR Handbook' by Merrill I. Skolnik? It's
big, over 1500 pages & boring, but covers the history & technology of
Here is an early edition:
Here is a copy of the new, third edition.
Oh come on, I know how RADAR works, I even own my own low power X-band
Doppler unit. It's a blast to play with. I won't even pretend to know
how that huge SOB ALTAIR works. The site mentions in the specifications
"Modulation: CW and Linear FM Chirp" What do you make of that? Two
different modes or a combination? Darn it, I wish I had asked more about
it but a lot of the information was classified so I don't know how much
I could have learned. There were guys wandering around out there who
could make you feel like am amoeba because they were so much smarter.
They all seemed to come from those alphabet universities. *snicker*
'FM Chirp' is a side effect of pulse modulation of some transmitter
Those 1500+ pages go into a lot of details that you might find
My MOS was broadcast engineer, but I did spend some time repairing
Korean War era RADAR systems at Ft. Rucker. I really pissed of the
RADAR tech I was assigned to work with. he would spend a half hour
hauling everything from the truck to the RADAR site while I went in with
a Simpson 260 and the manual. I would diagnose the problems before he
was finished hauling everything the quarter mile walk between were we
were allowed to park, and the base of the antennas. He got even madder
when I told him the only training that I had was studying the W.W.II
aircraft RADAR manuals in my high school's physics lab. The final blow
was when I told him that RADAR was a stripped down TV set with no sound.
I bet those guys would have been lost looking at the 40+ 'D' sized
schematics for the DSP based Microdyne RCB2000 dual telemetry receiver &
digital combiner if they were still alive in 2000. Rf was down
converted to a 70 MHz IF center frequency, and sampled from 50 to 90
MHz. Then the data was processed through FIR filters. A standard 70
MHz analog IF was created after the IF filter to allow the data to be
recorded on standard instrumentation recorders. 70 MHz IF is a holdover
from RADAR and early sat IF systems. It was also used in land based
telcom microwave relays.
On Wed, 16 Dec 2009 08:34:29 -0500, Stormin Mormon wrote:
I hate soldering surface-mount stuff by hand, though - and doing those
kinds of repair only works when it's not some unobtainable custom part
Personally I'd much rather electronic stuff was twice the size (like it
used to be), but at least easy to fix - but I'm in a minority there and
most folk want stuff as small as possible and who gives a crap when it
breaks as they can just buy a whole new one... :-(
The same with me. I have a lot of trouble sleeping any set schedule,
so there is no way that I could work full time. I keep busy repairing
computers to give away, do a little free consulting and tech support for
a business owned by some friends. Anything to keep busy. :)
That is where I would have burnt the files to a disk before letting
them get near it again. :(
I was talking about fixing a TV transmitter, having never seen the
inside of one before. Hell, the only thing I had ever done at a TV
station before that was be on a kiddy TV show while I was in Elementary
I read a couple thousand pages of equipment manuals for the equipment
at that station, starting the first night on duty. After that, I knew
the basic configuration by heart when I had the first failure. :)
I was used to the older techs destroying things because their
training was 20+ years out of date.
The VA gave up on my health about five years ago, when they granted
100% disability 14 days after I had to file.
The two local electronics vocational courses were dropped several
years ago. The only people who express an interest in electronics don't
want to learn to solder, or any math so there isn't much that you can
teach them. They think that a couple hours of being shown how to use a
meter is all they really need to become experts.
On Sat, 12 Dec 2009 21:39:20 -0600, The Daring Dufas wrote:
I wish you still had pictures, too - I used to do a lot of exploration /
photography in old military places like that, but it's rare to find one
where it hasn't been stripped of equipment. Sounds like an interesting
:-) The PSU for our house alarm lives in an outlet on the underside of
the basement stairs - to secure it they backed off the outlet cover screw
a little and then tied it in place....
Why the person who installed the outlet didn't put it on the side of the
stairs, I don't know - it's not like there isn't plenty of room.
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