OT Microwave frequency question

Does anyone know what microwave frequency was used by the Premier Channel
in the mid 1980's to broadcast HBO in the SF Bay Area?

The reason I need the info is because I can obtain some of these old
microwave dishes and want to try them on WI-FI if the frequency is OK.

Please reply if you have info, TIA

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<©®©@®.©®©> wrote in message
> Does anyone know what microwave frequency was used by the Premier Channel
> in the mid 1980's to broadcast HBO in the SF Bay Area?
>
> The reason I need the info is because I can obtain some of these old
> microwave dishes and want to try them on WI-FI if the frequency is OK.

The gain of the dish is going to be proportional to the size and freq that
it's used with.

A 3' would work just as a 30' dish would except the gain and directivity of
the 30' dish would be more.
Now there are things like feed point distance and inpedence that would also
play into the efficency of the dish but what it all comes down to is how you
feed it and if you plan on using the horn that's on the dish or build your
own.

Adair

©®©@®.©®© hath wroth:

>Does anyone know what microwave frequency was used by the Premier Channel
>in the mid 1980's to broadcast HBO in the SF Bay Area?

I thought it was earlier than that.

>The reason I need the info is because I can obtain some of these old
>microwave dishes and want to try them on WI-FI if the frequency is OK.

My guess(tm) is that they used the MMDS frequencies from 2.5 to
2.7GHz. There was also a band at 2.1GHz for TV distribution. As I
vaguely recall, the feed had an RF amplifier and downconverter inside,
which probably will need to be "converted" to 2.4GHz to work.
Something like this article:
| http://apache.airnet.com.au/~fastinfo/wireless/PacMon/
| http://www.mrx.com.au/wireless/ConfierModifications.htm

Also, please note that the maximum gain from a 0.6 meter diameter dish
antenna is about:
gain = 9.87 * Dia^2 / wavelength^2 * (feed efficiency)
gain = 9.87 * 600mm^2 / 125mm^2 * 0.4
gain = 91
dBi = 10 log(91) = 19.5dBi
The 40% efficiency (that's the 0.4) is probably optimistic. I don't
know the exact size of the STV dish, but I suspect it's close.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558