Hello Guys.

Sorry I do not read all message. John right.

I have IC-910H and do not have problem under VO-52 operating. But I have small VHF UHF antennas and good SWR.

Regards.

-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of tosca005@umn.edu Sent: Wednesday, November 21, 2012 6:50 PM To: 'Amsat bb' Subject: [amsat-bb] Re: Who is using a IC-910 with Maspro Antennas?

Note that Jan is specifically asking about VO-52 (mode UV), *NOT* FO-29 (mode VU). There is a big difference. When the uplink is VHF, the third harmonic of 145 MHz is 435 MHz so desense is often a problem. I have always noticed that difficulty with my FT-847 on FO-29 in the absence of external filtering, but a desense filter (filter out the 435 MHz harmonic from the 145 MHz side of the radio) is very helpful. But on mode UV, the transmitter is in the 435 MHz band and so interference in the 145 MHz band should be small. I have always found it extremely easy to operate VO-52 on my FT-847 without any particular extra filtering, unlike FO-29. And it sounds like Jan likewise was successful in working VO-52 in the past with his (now eliminated) FT-847.

So, this leads me to believe that Jan's system does have some problem. I am not familiar with either the IC-910 or the Maspro antennas, so I can't diagnose further. Separate bandpass filters on the VHF and UHF sides of the radio can likely help, but there may be more to the problem than meets the eye. At least it seems so from my state of ignorance about his specific equipment.

73 de W0JT John P. Toscano

On Nov 21 2012, 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

_______________________________________________ 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

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

-- With regards PE0SAT Internet web-page http://www.pe0sat.vgnet.nl/ _______________________________________________ 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