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 > _______________________________________________ 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
