Nice list! The FT-4700 does tones.

73, Joe kk0sd

-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of JoAnne Maenpaa Sent: Tuesday, October 20, 2009 10:45 AM To: [email protected] Subject: [amsat-bb] Re: HT supports full duplex satellite operation

Hello Michael,

http://www.thathamkid.com/website/ham-radio/full-duplex-radios is one place to find a list.

-- 73 de JoAnne K9JKM [email protected] Editor, AMSAT News Service Copy Editor, AMSAT Journal

_______________________________________________ Sent via [email protected]. 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

I intended to reply both to Michael and the BB, but I see that I simply responded to him and not to "all" in my earlier note.

My sense from his original post is that he is looking only for current-production HTs, and I believe the Alinco is it when it comes to full-fuplex-capable HTs.

That being said, I have been doing some related research over the past several months. Some BB readers may recall a post I made a few months ago about "the fully rechargeable satellite station." I have done some other things that I hope to include in an article for an upcoming issue of  "The AMSAT Journal," and I have discovered something that, I believe, could benefit all of us who enjoy using handheld stations.

In addition to the TH-F6A HT from Kenwood, I have had an opportunity to use a Yaesu VR-500 handheld all-mode receiver. The general coverage receiver in the Kenwood is all-mode, as is the VR-500. Either also can serve as a receive radio for a station on the linear satellites, albeit with manual Doppler tuning.

Most notable for those of us who enjoy using handheld stations for the FM satellites is the fact that the Kenwood's general coverage receiver and the Yaesu VR-500 each offer tuning steps down to 1 kHz and below, even in FM. As I recall, the Kenwood HT can tune as finely as 33 Hz. The VR-500 will tune as finely as 100 Hz. I routinely tune it in 1 kHz steps on the FM satellites. Doing so enables me to track Doppler on the UHF downlinks of our FM satellites much more accurately, and that has made a big difference in my ability to make handheld contacts. Those who choose to ignore the inarguable fact that high power isn't necessary for effective FM LEO satellite contacts still make things difficult for me and others who enjoy using handheld stations. I've accepted the fact that the situation won't ever change, which is disappointing.

Nonetheless - from here, I believe that using a 2-radio full-duplex setup for the FM satellites that incorporates a receive radio capable of tuning in 1 kHz (or finer) steps actually represents the most effective option because of the improved receive capability the smaller tuning steps provide.

Many of us would like to see more HT manufacturers adopt full-duplex as a feature on at least one current-production model. I also would like to cast my vote for (1) general coverage receivers that, like the TH-F6A, are all-mode, and (2) tuning steps finer than 5 kHz for FM that will work on both transmit AND receive.

I am thrilled with the news that AMSAT is moving forward with plans to build and launch a 1U cub sat with a U/V (Mode B) transponder. However, consistently hitting the uplink with HTs that tune no finer than 5 kHz will be a challenge. I learned that last winter when the ISS repeater was active in Mode B. When I used my FT-817 as a transmit radio and could use the main tuning dial to infinitely fine-tune the uplink, I had much better - and more consistent - success hitting the uplink than with my HT, which will only tune in 5 kHz steps.

73 to all,

Tim - N3TL

73 to all,

Tim - N3TL Athens, Ga. - EM84ha

________________________________ From: Alan P. Biddle [email protected] To: Michael Chen [email protected]; [email protected] Sent: Tuesday, October 20, 2009 12:02:14 PM Subject: [amsat-bb] Re: HT supports full duplex satellite operation

Michael,

That is a good reference from JoAnne.  Most on the list will work well, particularly the TH-D7 and the IC-W32A.  However, before you purchase one, be certain to research how well it actually works for satellite ops.  For instance, I have an Alinco DJ-G7 which has great specifications, but works very poorly for satellite ops, though it is a nice general purpose unit.

Alan WA4SCA

-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Michael Chen Sent: 20 October, 2009 09:12 To: [email protected] Subject: [amsat-bb] HT supports full duplex satellite operation

All,

Could anyone list the HT models (available today in the market) that support full duplex satellite operation? I know I can get connected with two HTs and portable cross Yagi. Just need a simpler solution. IC-W23AT and TH-D7 are discontinued.

Michael Chen, BD5RV/4 Email: [email protected] MSN: [email protected] Skype: michael-bd5rv _______________________________________________ Sent via [email protected]. 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 [email protected]. 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 Drew,

My "work-around" (unless someone comes out with a finer-tuning HT between now and then!) is simple. I'm going to use a combination of the 5 kHz and 12.5 kHz tuning steps on my HT to program a set of memories that "Doppller tunes" the uplink in 2.5 kHz steps. That way, I'll be able to stay fairly close to the uplink throughout the pass. I'm confident the "one true rule" will still apply regardless of the receiver design. It has on AO-7 and VO-52 when I've worked passes using AFSK through an HT to send CW on those Mode B satellites.

I'll use the same downlink in each memory because I've done just the opposite with our Mode J satellites - that is, use the same VHF uplink all the time and only Doppler-tune the downlink.

Please don't mistake my comments as any kind of criticism; they aren't intended that way at all. I'm looking forward to the challenge, and just hope others understand that one true rule and its impact on Mode B operations.

73 to all,

Tim - N3TL

________________________________ From: Andrew Glasbrenner [email protected] To: Tim - N3TL [email protected] Cc: [email protected]; Michael Chen [email protected]; [email protected] Sent: Tuesday, October 20, 2009 1:20:17 PM Subject: Re: [amsat-bb] Re: HT supports full duplex satellite operation

I am thrilled with the news that AMSAT is moving forward with plans to build and launch a 1U cub sat with a U/V (Mode B) transponder. However, consistently hitting the uplink with HTs that tune no finer than 5 kHz will be a challenge. I learned that last winter when the ISS repeater was active in Mode B. When I used my FT-817 as a transmit radio and could use the main tuning dial to infinitely fine-tune the uplink, I had much better - and more consistent - success hitting the uplink than with my HT, which will only tune in 5 kHz steps.

It's all in the receiver design. The ISS D-700 isn't designed as a satellite receiver, and has a narrow front end.

Think of it this way. With 5 khz steps you are always within 2.5 khz of being "on frequency", right?

We operate the V/U FM satellites all the time without tuning the uplink, and that means we are up to 3 khz off, and everything works fine! So 2.5 khz will be a piece of cake too, plus folks will hear the 2m downlink much easier.

73, Drew KO4MA

All,

Many thanks for those replies off the list. Yes, just like Tim said, I am looking for HTs that are currently in production. I am trying to get local high school club station to work via the satellites. A true full-duplex HT can make this process easily accepted by the students. At the same time, the school will always require new HT purchase from the market.

It's sad that I can't find a good choice. DJ-G7 does not seem to be good enough.

I believe there will be a boost of satellite operation in China with the launch of XW-1.

Michael Chen, BD5RV/4 Email: [email protected] MSN: [email protected] Skype: michael-bd5rv

On Wed, Oct 21, 2009 at 12:57 AM, Tim - N3TL [email protected] wrote:

I intended to reply both to Michael and the BB, but I see that I simply responded to him and not to "all" in my earlier note.

My sense from his original post is that he is looking only for current-production HTs, and I believe the Alinco is it when it comes to full-fuplex-capable HTs.

That being said, I have been doing some related research over the past several months. Some BB readers may recall a post I made a few months ago about "the fully rechargeable satellite station." I have done some other things that I hope to include in an article for an upcoming issue of  "The AMSAT Journal," and I have discovered something that, I believe, could benefit all of us who enjoy using handheld stations.

In addition to the TH-F6A HT from Kenwood, I have had an opportunity to use a Yaesu VR-500 handheld all-mode receiver. The general coverage receiver in the Kenwood is all-mode, as is the VR-500. Either also can serve as a receive radio for a station on the linear satellites, albeit with manual Doppler tuning.

Most notable for those of us who enjoy using handheld stations for the FM satellites is the fact that the Kenwood's general coverage receiver and the Yaesu VR-500 each offer tuning steps down to 1 kHz and below, even in FM. As I recall, the Kenwood HT can tune as finely as 33 Hz. The VR-500 will tune as finely as 100 Hz. I routinely tune it in 1 kHz steps on the FM satellites. Doing so enables me to track Doppler on the UHF downlinks of our FM satellites much more accurately, and that has made a big difference in my ability to make handheld contacts. Those who choose to ignore the inarguable fact that high power isn't necessary for effective FM LEO satellite contacts still make things difficult for me and others who enjoy using handheld stations. I've accepted the fact that the situation won't ever change, which is disappointing.

Nonetheless - from here, I believe that using a 2-radio full-duplex setup for the FM satellites that incorporates a receive radio capable of tuning in 1 kHz (or finer) steps actually represents the most effective option because of the improved receive capability the smaller tuning steps provide.

Many of us would like to see more HT manufacturers adopt full-duplex as a feature on at least one current-production model. I also would like to cast my vote for (1) general coverage receivers that, like the TH-F6A, are all-mode, and (2) tuning steps finer than 5 kHz for FM that will work on both transmit AND receive.

I am thrilled with the news that AMSAT is moving forward with plans to build and launch a 1U cub sat with a U/V (Mode B) transponder. However, consistently hitting the uplink with HTs that tune no finer than 5 kHz will be a challenge. I learned that last winter when the ISS repeater was active in Mode B. When I used my FT-817 as a transmit radio and could use the main tuning dial to infinitely fine-tune the uplink, I had much better - and more consistent - success hitting the uplink than with my HT, which will only tune in 5 kHz steps.

73 to all, Tim - N3TL

73 to all, Tim - N3TL Athens, Ga. - EM84ha ________________________________ From: Alan P. Biddle [email protected] To: Michael Chen [email protected]; [email protected] Sent: Tuesday, October 20, 2009 12:02:14 PM Subject: [amsat-bb] Re: HT supports full duplex satellite operation

Michael,

That is a good reference from JoAnne.  Most on the list will work well, particularly the TH-D7 and the IC-W32A.  However, before you purchase one, be certain to research how well it actually works for satellite ops.  For instance, I have an Alinco DJ-G7 which has great specifications, but works very poorly for satellite ops, though it is a nice general purpose unit.

Alan WA4SCA

-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Michael Chen Sent: 20 October, 2009 09:12 To: [email protected] Subject: [amsat-bb] HT supports full duplex satellite operation

All,

Could anyone list the HT models (available today in the market) that support full duplex satellite operation? I know I can get connected with two HTs and portable cross Yagi. Just need a simpler solution.. IC-W23AT and TH-D7 are discontinued.

Michael Chen, BD5RV/4 Email: [email protected] MSN: [email protected] Skype: michael-bd5rv _______________________________________________ Sent via [email protected]. 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 [email protected]. 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