[amsat-bb] Re: Who is using a IC-910 with Maspro Antennas?
domenico.i8cvs at tin.it
Wed Nov 21 12:09:13 PST 2012
Hi Jan, PA0SAT
Your problem with VO-52 ,uplink 435 MHz and downlink 145 MHz
is not due obviously by armonics but by 435 MHz overloading the
IC-910 receiving 145 MHz because probably this tranceiver has a
lover 1 dB compression point at 144 MHz in comparison to a FT-847
and so it is more subject to intermodulation.
Since you do not have problems using the same Maspro antennas and
a FT-847 the only one to be cured is the IC-910
I suggest you to try a duplexer with the antenna connected to the
common and the 2 meter port connected to the IC-910 while the
70 cm port is closed into a 50 ohm termination.
The 2 meter section act as a low-pass filter and the 70 cm port as
a high-pass filter while the 50 ohm termination dissipates the
435 MHz signal.
----- Original Message -----
From: "PE0SAT | Amateur Radio" <pe0sat at vgnet.nl>
To: "Dimitry Borzenko" <dibor at iname.com>
Cc: "Amsat bb" <amsat-bb at amsat.org>
Sent: Wednesday, November 21, 2012 6:03 PM
Subject: [amsat-bb] Re: Who is using a IC-910 with Maspro Antennas?
> Hi Dimitry,
> I know of this filter, but these are for working FO-29 when the uplink
> is 145 and the downlink 435.
> The Harmonics produced by the 145 uplink signal interfere with the 435
> downlink. Now I experience the
> same with VO-52 but there the uplink 435 and the donwlink 145 ???
> So why is the 435 uplink interfering with the 145 downlink ????
> Could this be a harmonic problem???
> 73 Jan PE0SAT
> On 21-11-2012 17:06, Dimitry Borzenko wrote:
> > Hello Jan.
> > Try "Desense" filter.
> > More info here - http://www.amsat.org/amsat-new/articles/Mode-J/
> > Regards.
> > -----Original Message-----
> > From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org]
> > On
> > Behalf Of PE0SAT | Amateur Radio
> > Sent: Tuesday, November 20, 2012 8:12 PM
> > To: Amsat bb
> > Subject: [amsat-bb] Who is using a IC-910 with Maspro Antennas?
> > Hi,
> > Thanks for reading this message. I have exchanged my FT-847 for an
> > IC-910H and now when I try to
> > work VO-52 my UHF uplink signal interferes with the VHF downlink. Are
> > the any people out there that
> > experience the same with this combination?
> > I tried with and without pre-amp, RHCP and LHCP but the problems
> > doesn't go away :(
> > I do know that there can be problems when working FO-29 and a mode-j
> > filter can solve this, but I
> > never experiences this when working VO-52.
> > 73 Jan PE0SAT
> With regards PE0SAT
> Internet web-page http://www.pe0sat.vgnet.nl/
> Sent via AMSAT-BB at amsat.org. Opinions expressed are those of the author.
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