[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: receiving system design tradeoffs



I read, heard or imagined that the actual wind load of a dish antenna didn't
change with perforations (well small ones not the size of baseballs and up!)
since the wind couldn't pass thru them at any appreciable speed. They were
lighter of course.

The size of the holes is limited by the higher frequency limits of your
receiver. Something about a "waveguide beyond cutoff"

Additionally, before my TVRO I used the Primestar offset and mounted it on
my Yaesu 500/450 combo. The gripping power of the 450 clamping system saved
this combo many times. However, I had to frequently climb up and re-orient
the antennas. Not bad in the summer, either month...

----- Original Message -----
From: "Doug Faunt N6TQS +1-510-655-8604" <faunt@panix.com>
To: <amsat-bb@AMSAT.Org>
Sent: Wednesday, February 05, 2003 8:54 PM
Subject: Re: [amsat-bb] receiving system design tradeoffs


>
>    From: "Frederick M. Spinner" <fspinner@hotmail.com>
>    Date: Thu, 06 Feb 2003 01:21:33 +0000
>
>    >  A smaller dish is more likely to be suitable for a Yaesu az-el
rotor, and
>    >doesn't require as elaborate a mounting structure.
>
>    And herein lies one of the real problems we face, that the Yaesu rotors
are
>    really too light duty to do what they are supposed to do.
>    Again, I have one, and I paid $525 for new (which was a screaming
deal).
>    Again, $75 TVRO actuators beat the pants off of the Yaesus.
>
>    I'll end up using that rotor at least initially since it's easier to
do.
>    But man,  it is weakly built to be as expensive as it is...but I think
>    a 3' offset would work if you limited the max operating windspeed,
balanced
>    it well, and pointed the system straight up when not using it.
>
> I believe that a 3' aluminum dish that was perforated properly would
> give just as much gain as a solid dish of that size, but would be much
> lighter in both weight and windload.  Now, if we could easily locate
> such.
>
> I'd love to have one to upgrade my G3RUH setup.
>
> 73, doug
>
>
>
>
> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT member? Join now to support the amateur satellite program!
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>

----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home