http://www.dci.ca/?Section=Products&SubSection=Amateur
You can buy a custom low pass filter for 2-meters from DCI. Marex had DCI custom build a 2-meter filter for simular usage on Mir. The filter passed 144.000 - 146.000, and had a notch added for 143.xxx. The filter worked great. It reduced most noise out side of the band and it blocked out a 50 watt transmitter located about 10 meters away. --- On Wed, 4/27/11, Dee <morse...@optonline.net> wrote: > From: Dee <morse...@optonline.net> > Subject: [amsat-bb] Re: searching advice on low hpass filter for 146 MHz > To: "'Werner Kullmann, HB9BNK'" <hb9...@uska.ch>, amsat-bb@amsat.org > Date: Wednesday, April 27, 2011, 10:25 AM > Werner, > Since you are using a very good rig and adding a great > preamp, to hear what > you are after and expense involved might be as simple as > adjusting the gain > (SP2000 indicates it is adjustable and already has a > helical front end) so > as to stop this interference. Doing this simple thing > might correct > everything--Let us know if it works. I adjusted the > gain of my preamp to > stop similar type intermod. > 73, > Dee, NB2F > > -----Original Message----- > From: amsat-bb-boun...@amsat.org > [mailto:amsat-bb-boun...@amsat.org] > On > Behalf Of Werner Kullmann, HB9BNK > Sent: Wednesday, April 27, 2011 9:42 AM > To: amsat-bb@amsat.org > Subject: [amsat-bb] searching advice on low hpass filter > for 146 MHz > > To improve the reception of the sats on 145.9xx MHz > with my little yagi, I > recently acquired a SSB-preamplifier SP-2000. To my dismay, > the reception on > my IC910H was intermittend heavily distorted. > > After a while I found, that a nearby located commercial > transmitter (POCSAG) > emitting bursts on 147.300 is so strong, that the frontend > of the IC910H (or > its AGC) practically quites the receiver on 145.900. > When the bursts stop, > reception resumes. > Difficult to qso. > > I have experimented with a large cavity filter and found, > that the impact of > the bursts can be reduced, so that normal satellite work is > possible again. > > Now I am looking for advice on how to build a steep low > pass filter, > eliminating everything above 146 MHz, to be mounted before > the preamp on the > mast. The filter must however be capable to accept the rf > power, if I work > in V/U mode. > > Thank you for any ideas ! > > Werner, HB9BNK > _______________________________________________ > Sent via AMSAT-BB@amsat.org. > Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur > satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > > > _______________________________________________ > Sent via AMSAT-BB@amsat.org. > Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur > satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
