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

Re: Noise, Bandwidth and Gain



"Keeth Jim (Indy)" wrote:
> 
>         On Wednesday, January 10, 2001 11:29 AM, Gary Memory wrote:
> 
>         >Any attempt to monitor AO-40 or any other signal at S-Band has been
>         >fruitless.  However, I recently added a cavity filter cut for 2.4
> MHz
>         >between the Conifer amp and the antenna and WOW!  Signals have
> appeared from
>         >nowhere.
> 
> Gary...  I also live in a "high RF environment"  TV stations, pagers, etc.
> I put a high-pass filter between my 2.4 GHz antenna and preamp.  It's been
> several years, but I think the cutoff freq was around 1.5 GHz.  It was
> relatively easy to make a high-pass with low loss.  My attempts at making
> low loss band-pass filters of various types haven't turned out so well.
> 
> If you've got a good low loss cavity filter, you're luckier than most of us!
> 

I like where this thread is going , I have always tried to get my buddies to use
some sort of a "preselector " in front of the receiver that they put on a
mountaintop , so that the reciever and mixers won't have so much hi-level stuff
to battle and overload on ....

speaking of this and the thread as it is , about S-band filters , I picked up
some of the 2.4GHz "stripline" filters ( some call them interdigital filters ) ,
from Mavin.com for $5 US a piece , and hey these puppies are really nice and
have a good bandpass of 2.35 to 2.5 GHz , with about 50db attenuation out of the
passband and only about appx 1db of ripple on the passband ( using an IFR8000
tracking generator ) , so for that kind of money you can't go wrong , oh and I
forgot , the insertion loss is about 5 to 6 db depending on the unit , real nice
box too , very small , so check it out at their website ,
http://mavin.com/microwave/microwave1.html , and check it out :)

Good stuff for cheapies like me ;^}
-- 
Douglas Cole   N7BFS
AMSAT#26182 , K2 # 544
Spokane IRLP node 145.250 owner
http://www.users.qwest.net/~cdoug3
Registered Linux user # 188922
----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home