Fw: 2M desense on Icom IC-9700
----- Forwarded Message ----- From: BeetleJerald Oliver [email protected]To: [email protected] [email protected]Sent: Wednesday, May 6, 2020, 02:55:41 PM CDTSubject: 2M desense on Icom IC-9700 I just replaced my Yaesu FT-847 with the Icom IC-9700. I am having problem with 2M uplink overloading (desense) the 70CM downlink, resulting in not being able to use RS-44, FO-29, or SO-50. It is the same antenna system that I used with the FT-847 and I experienced no problem at all with the FT-847. SWR on both VHF/UHF is quite low using M2 CP yagis on fiberglas boom, 11 feet apart. I have the problem whether I use the preamps, or not. Even at 5W out, it is quite noticeable. Anyone else had this problem? KJ4EU Jerry
Jerry, Comparing the 9700 to my 9100 I also noticed that it was much more prone to desense, it was not as bad here as what you are seeing but it was there, same antennas here BTW. The desense with the lack of 9600 packet support made it easy for me to go back to my 9100 and sell the 9700. Had I kept it my next plan was to put a diplexer in line on the 70cm side with a 50 ohm load on the 2m port, this would probably be your best option and putting it before an external preamp would also be best if you are using one.
73 Kevin WA7FWF
On 5/6/2020 6:18 PM, BeetleJerald Oliver via AMSAT-BB wrote:
----- Forwarded Message ----- From: BeetleJerald Oliver <[email protected]>To: [email protected] <[email protected]>Sent: Wednesday, May 6, 2020, 02:55:41 PM CDTSubject: 2M desense on Icom IC-9700I just replaced my Yaesu FT-847 with the Icom IC-9700. I am having problem with 2M uplink overloading (desense) the 70CM downlink, resulting in not being able to use RS-44, FO-29, or SO-50. It is the same antenna system that I used with the FT-847 and I experienced no problem at all with the FT-847. SWR on both VHF/UHF is quite low using M2 CP yagis on fiberglas boom, 11 feet apart. I have the problem whether I use the preamps, or not. Even at 5W out, it is quite noticeable. Anyone else had this problem? KJ4EU Jerry _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
I have to say I'm not getting desense with my IC-9700, unless I'm using more power than is needed or should be using on the SSB Sats.
Maybe try to lower your power? RS-44 can easily be worked at around 2% (2w) power and I work SO-50 at 0-3% every time (500mw-3w)
On Wed, May 6, 2020 at 6:52 PM Kevin via AMSAT-BB [email protected] wrote:
Jerry, Comparing the 9700 to my 9100 I also noticed that it was much more prone to desense, it was not as bad here as what you are seeing but it was there, same antennas here BTW. The desense with the lack of 9600 packet support made it easy for me to go back to my 9100 and sell the 9700. Had I kept it my next plan was to put a diplexer in line on the 70cm side with a 50 ohm load on the 2m port, this would probably be your best option and putting it before an external preamp would also be best if you are using one.
73 Kevin WA7FWF
On 5/6/2020 6:18 PM, BeetleJerald Oliver via AMSAT-BB wrote:
----- Forwarded Message ----- From: BeetleJerald Oliver <[email protected]>To: [email protected] [email protected]Sent: Wednesday, May 6, 2020, 02:55:41 PM CDTSubject: 2M desense on Icom IC-9700
I just replaced my Yaesu FT-847 with the Icom IC-9700. I am having
problem with 2M uplink overloading (desense) the 70CM downlink, resulting in not being able to use RS-44, FO-29, or SO-50. It is the same antenna system that I used with the FT-847 and I experienced no problem at all with the FT-847. SWR on both VHF/UHF is quite low using M2 CP yagis on fiberglas boom, 11 feet apart. I have the problem whether I use the preamps, or not. Even at 5W out, it is quite noticeable. Anyone else had this problem?
KJ4EU Jerry _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
I also have not had desense issues on my 9700 compared to my 910. I actually removed my mode J filter.
No problems here. N3CRT Charles Reiche
On Thu, May 7, 2020 at 11:34 AM KI7UNJ Tucker via AMSAT-BB < [email protected]> wrote:
I have to say I'm not getting desense with my IC-9700, unless I'm using more power than is needed or should be using on the SSB Sats.
Maybe try to lower your power? RS-44 can easily be worked at around 2% (2w) power and I work SO-50 at 0-3% every time (500mw-3w)
On Wed, May 6, 2020 at 6:52 PM Kevin via AMSAT-BB [email protected] wrote:
Jerry, Comparing the 9700 to my 9100 I also noticed that it was much more prone to desense, it was not as bad here as what you are seeing but it was there, same antennas here BTW. The desense with the lack of 9600 packet support made it easy for me to go back to my 9100 and sell the 9700. Had I kept it my next plan was to put a diplexer in line on the 70cm side with a 50 ohm load on the 2m port, this would probably be your best option and putting it before an external preamp would also be best if you are using one.
73 Kevin WA7FWF
On 5/6/2020 6:18 PM, BeetleJerald Oliver via AMSAT-BB wrote:
----- Forwarded Message ----- From: BeetleJerald Oliver <[email protected]>To: [email protected] [email protected]Sent: Wednesday, May 6, 2020, 02:55:41 PM CDTSubject: 2M desense on Icom
IC-9700
I just replaced my Yaesu FT-847 with the Icom IC-9700. I am having
problem with 2M uplink overloading (desense) the 70CM downlink, resulting in not being able to use RS-44, FO-29, or SO-50. It is the same antenna system that I used with the FT-847 and I experienced no problem at all
with
the FT-847. SWR on both VHF/UHF is quite low using M2 CP yagis on fiberglas boom, 11 feet apart. I have the problem whether I use the preamps, or not. Even at 5W out, it is quite noticeable. Anyone else had this problem?
KJ4EU Jerry _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions expressed
are solely those of the author, and do not reflect the official views
of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
-- *Casey Tucker KI7UNJ* https://twitter.com/KI7UNJ _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
I have to agree, I got zero desense.
I am using a VHF 4 Element Quad beside a 7 Element UHF quad on a 6ft boom fiberglass boom. This is with running full power on either band.
Mike va3mw
On Thu, May 7, 2020 at 2:17 PM Charles Reiche via AMSAT-BB < [email protected]> wrote:
I also have not had desense issues on my 9700 compared to my 910. I actually removed my mode J filter.
No problems here. N3CRT Charles Reiche
On Thu, May 7, 2020 at 11:34 AM KI7UNJ Tucker via AMSAT-BB < [email protected]> wrote:
I have to say I'm not getting desense with my IC-9700, unless I'm using more power than is needed or should be using on the SSB Sats.
Maybe try to lower your power? RS-44 can easily be worked at around 2%
(2w)
power and I work SO-50 at 0-3% every time (500mw-3w)
On Wed, May 6, 2020 at 6:52 PM Kevin via AMSAT-BB [email protected] wrote:
Jerry, Comparing the 9700 to my 9100 I also noticed that it was much more prone to desense, it was not as bad here as what you are seeing but it was there, same antennas here BTW. The desense with the lack of 9600 packet support made it easy for me to go back to my 9100 and sell the 9700. Had I kept it my next plan was to put a diplexer in line on the 70cm side with a 50 ohm load on the 2m port, this would probably be your best option and putting it before an external preamp would also be best if you are using one.
73 Kevin WA7FWF
On 5/6/2020 6:18 PM, BeetleJerald Oliver via AMSAT-BB wrote:
----- Forwarded Message ----- From: BeetleJerald Oliver <[email protected]>To: [email protected] [email protected]Sent: Wednesday, May 6, 2020, 02:55:41 PM CDTSubject: 2M desense on Icom
IC-9700
I just replaced my Yaesu FT-847 with the Icom IC-9700. I am having
problem with 2M uplink overloading (desense) the 70CM downlink,
resulting
in not being able to use RS-44, FO-29, or SO-50. It is the same
antenna
system that I used with the FT-847 and I experienced no problem at all
with
the FT-847. SWR on both VHF/UHF is quite low using M2 CP yagis on fiberglas boom, 11 feet apart. I have the problem whether I use the preamps, or not. Even at 5W out, it is quite noticeable. Anyone else
had
this problem?
KJ4EU Jerry _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum
available
to all interested persons worldwide without requiring membership.
Opinions expressed
are solely those of the author, and do not reflect the official views
of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings:
https://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views
of
AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
-- *Casey Tucker KI7UNJ* https://twitter.com/KI7UNJ _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
participants (5)
-
BeetleJerald Oliver -
Charles Reiche -
Kevin -
KI7UNJ Tucker -
Michael Walker