Saturday, February 05, 2011

Envy

See, the French have style. Even for radio transmitter sites! Pretty sure I saw this in a James Bond movie. Or was it Buck Rogers?

(More here, here and here [a monsterpower AM with 6-wire "open" coax to the towers] This is the "transmitter row" for Marseille, which slightly resembles Southern Indiana. An "aha" moment in terms of our local wineries.)

11 comments:

Anonymous said...

True geekism is feed line envy.

Terry
Fl

Ps. Takes one to know one ;)

Old Grouch said...

Anything that doesn't radiate at least 10KW isn't REAL radio. ;-)

(Was it WLW in the high-power days where they had to bounce the carrier whenever there was a nearby lighting strike, as the RF would maintain an arc on the guy insulators?)

warlocketx said...

For pure geekism I'll see your French radio transmitters, and raise you a Russian high-voltage experiment. Yes, it's real -- use Google Earth at 55 55'26N, 36 49'07E.

Once upon a time Mexico had no limit on AM transmitter power, and there were several stations along the Rio Grande with half a million watts and up. Of course, getting that much power to the antenna is well-nigh impossible, but at least plate power to the finals was impressive. They were mostly the province of fundamentalist preachers, who sent out continual appeals for money in exchange for tchotchkes of various kinds.

In the Fifties and Sixties, making your way across west Texas on US80 or US90, that was often all the radio you could pick up. The situation has been immortalized in music.

Regards,
Ric

Ed Skinner said...

Many years ago, our high school electronics class visited a high power FM station near Memphis. Someone asked about lightning damage and the chief engineer said we could come visit during the next storm. On a likely afternoon, I remember sitting out (in wooden chairs) near the transmitter shack and watching as the top of the antenna a couple hundred yards away took a series of pulses from Thor. A few seconds later, equally deafened by the thunder clasp, the chief engineer shouted, "That probably ate up eight to twelve feet of copper. Who wants to carry up the new piece?"
He got no takers from us.

Eck! said...

Having worked on repeater sites, FM broadcast, and a little AM broadcast
(little 5KW) I can say I've seen towers and then some. However I turn into a clingon (and require pry me off) at more than 25FT.

If you like tall spikes checkout Needham MA, home of the major broadcasters for the Boston area. Minimum altitude for the area when flying over is 2000ft.

Me my puny tower is only 30ft plus mast for the VHF/UHF antenna farm and lowers to the ground for service. trees server for the HF wires.

I can still drool, as I grew up near
the various wireless stations on LI.
http://longislandgenealogy.com/Wireless/Wireless.html

Eck!

wolfwalker said...

[geek mode on]James Bond is probably where you're remembering it from -- the transmitter tower vaguely resembles some of the equipment seen when the giant transmitter dish is revealed in GoldenEye. That dish is actually the Arecibo transceiver in Puerto Rico, the largest radio-telescope in the world.

[geek mode off, for now]

Old Grouch: that's a story I hadn't heard, but I wouldn't doubt it. WLW was a legend in days now long past: during the thirties, its transmitter was rated at 500,000 watts, and under the right conditions its signal could be heard in London.

Yes, London. As in England.

Roberta X said...

Old Grouch: Depending on how close you set the ball or horn gap at the base of an AM tower (and it's caution to set them pretty close: the closer the gap, the smaller the voltage spike from lightning), any AM transmitter can sustain an arc.

The arc-sensing-and-extinguishing circuit probably originated at the WLW big rig but most transmitter have them now. The Collins 20V line (scroll down) used an interesting system: they ran 100 VDC down the coax, in series with a current-limiting resistor and a sensitive relay. If there was an arc at the tower base (or along the coax!), the relay coil would energize and shut off the plate voltage until the arc stopped. This worked great, except the 100 VDC was there any time the control circuits were powered up, even if the transmitter was otherwise off. If, then, the station uses three feedthrough insulators and a but of copper strap to switch between transmitters, at least one of which is a Collins 20V, you are in for a "surprise." Ow!

One place where I worked had an early solid-state transmitter and the ballgap was set CLOSE. Flies would blunder in, fry and sit there sizzling (on the air!) while you fetched a wooden-handled broom and the keys, walked waaaaay out to the tower and swept the remains out. Mind the gap!

Roberta X said...

make that "bit of copper strap," not "but."

Roberta X said...

Warlocktx: LOVE that HV site!

Stranger said...

I was always amused by XERA's lineup. In the 1940's XERA would rent five minute blocks on the 500KW station to all comers. So those of us in Lake of the Woods country could always get someone asking for "Contributions to the Lord to keep this important work going. Remember, send your contributions to the Lord, `my address is....'"

But speaking of towers, I rashly said I would climb a certain radio tower. I regretted it when I found it was 200 feet of rusty Rohn with three guys at the top.

Stranger

Eck! said...

tower story..

Back when ('72 summer) we had to put up a small dish for 858mhz point to point.
The deal was tom up top, I'd go to about 25ft and the new kid was the ground guy. I hate climbing. Anywho the pole is a 60ft telephone pole, yes
real wood, and unknown age. Tom goes up with the block and runner rope, I start up to clear lines and at about 20ft I grab a climbing spike and it
wiggles, huh! So I grab it and pull
and it's in my hand and not the pole, ahs#!^. I look up and yell to Tom and wave the pike at which point He pulls one out then he spikes in and does a double wrap of the belt and installs a bolt to secure to. I did too.
We finished the job and on the way down most all all the north side spikes and a few south side were found to be in rotting wood. That was the last time that pole had people on it. Later in the summer we would be there with a crane to drop it and replace with metal. The pole was about gone. I've not climbed anything wood since. Not even if it was growing.

Those that climb are braver than I.


Eck!