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.
73" de
i8CVS Domenico
----- Original Message ----- From: "PE0SAT | Amateur Radio" pe0sat@vgnet.nl To: "Dimitry Borzenko" dibor@iname.com Cc: "Amsat bb" amsat-bb@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@amsat.org [mailto:amsat-bb-bounces@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
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