> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu]On Behalf
> Of David VanHorn
> Sent: 06 February 2007 19:52
> To: Microcontroller discussion list - Public.
> Subject: Re: [EE] Which coax
>
>
.....
> Then you get into ladder line, and open wire line.
I've worked on a big HF site which had open wire feeders. Spacing was about
30cms or maybe a bit bigger impedance was 300 ohms. The curtain arrays
typically had 16 dipoles with reflectors; all this was connected together
with open wire feeder and then matched to 300 ohm and taken back to the
switching matrix where any transmitter could be switched into any array.
Transmitter power (there were 12 transmitters if I remember correctly) was
300kW (there are sites with 500kW tx's). Each service output erp would have
been about 20MW.

This was really big gear, and when there was an arc over, bits of antenna
fell out of the sky!!

Mike.

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