Re: [amsat-bb] Prime Star Dishes etc.

[Achim Vollhardt <avollhar@xxxxxxxxxxxxxxx>]

Hi folks,
I don't think any tv-sat LNC would be good for ham satellite operations,
because the phase noise of the used DRO's is much too bad for weak
signals with low bandwidth. They do a good job as a preamp, if stripped
off the mixer and DRO. You can also use the FETs in it for a 10 GHz
amplifier as they will do around 50-100 mW..

73s Achim, DH2VA

Jon Ogden wrote:
> 
> on 1/3/01 3:02 PM, Keeth Jim (Indy) at KeethJ@tce.com wrote:
> 
> > If you do the math, you find the image freuqency band is 9.8 to 10.3 GHz ...
> > pretty close to 10.451 GHz!  The problem is, there is a microstrip band pass
> > filter which passes only the 12.2 to 12.7 band and provides pretty good
> > image rejection.  Someone who is very clever might find a way to cut that
> > filter out and make it work for the 10.4 GHz band.
> 
> Depending on how the circuit is laid out and the type of substrate used,
> it's probably pretty easy.  At 10 GHz, a microstrip filter will likely be
> several open stubs spaced certain distances apart.  The transmission line
> should be a solid line through all theses stubs.  If you go in with an
> Exacto knife or Dremel tool you can just remove the stubs and viola! no more
> filter!
> 
> If it is a stripline design (basically a microstrip with another layer of
> dielectric and then a ground plane on top of the microstrip), it won't be so
> easy to modify (and may not be possible).
> 
> 73,
> 
> Jon
> NA9D
----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org