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Re: HT Satellite Ground stations.



  dear bob,
i didn't know about tnc ini delay, that is quite a problem (4 second).
otherwise, the HT could be used for pacsat 9k6 ;)

good testing & development !!

luis

Bob Bruninga wrote:

> On Sat, 5 Feb 2000, Luis Martins wrote:
>
> > now that is possible to change between radio and tnc control, wouldn't it be
> > possible to use the th-d7 for pacsat operation, the radio doesn't work
> > cross band with the tnc on, but it could be switched to vhf/9k6,
> > transmit, and switch back to uhf/9k6, assuming that the port commands
> > are fast enought.
>
> Dont know.  More testing needed.  THis info is only 2 days old now.
> Several things to test...
>
> 1) In my radio, the QSY is instant, but when you go back to TNC mode, it
> takes a 4 second re-init of the TNC?  But another station claims his does
> NOT do the re-init?  Still trying to find out what mode he is in.  I am in
> straight packet mode.  He may be in APRS mode...
>
> 2) PACSAT PROTOCOL I think requires rapid response.  When its your time to
> tramsmit, a 4 second delay to hear your ACKS would not work of course.
>
> 3) But if a 9600 baud bird gets authorized for UI digipeating, then the
> delay is OK, since you listen far more than you transmit..  And you only
> transmit a few packets per pass...  Just to report your position, status,
> and send any uplink messages.  At 9600 this takes about 1 second...
>
> bob
>
> > > Sure, TC 0 and TC 1 switches the serial port between radio control and
> > > TNC...
> > > Bob
> > >
> > > >
> > > > Thanks
> > > >
> > > > Daniel Lavoie
> > > > VE3DCL
> > > > ----- Original Message -----
> > > > From: "Bob Bruninga" <bruninga@nadn.navy.mil>
> > > > To: "TAPR APRS Special Interest Group" <aprssig@tapr.org>;
> > > > <htaprs@tapr.org>; <amsat-bb@AMSAT.Org>
> > > > Sent: Thursday, February 03, 2000 11:51 AM
> > > > Subject: [amsat-bb] HT Satellite Ground stations.
> > > >
> > > >
> > > > > Kenwood digital radio/TNC remote control,
> > > > >
> > > > > Tonight, I discovered how to switch the control port between the
> > > > > radio and the internal TNC so that my APRStk program can now both
> > > > > auto-tune the doppler and route the downlinked packets DURING the pass
> > > > > through the radio's single serial port.  Thus, PACSAT Receive-only
> > > > > stations can be assembled with nothing but a PC and the Kenwood HT on a
> > > > > 20 inch whip antenna.
> > > > >
> > > > > I have been using a 3/4 wave vertical (20.2") on my THD7 and can receive
> > > > > the downlink from any of the (working) pacsats  while they are above 20
> > > > > deg...(the antenna has over 7 dBi gain up at 40 deg or so on 435) and
> > > > > still works as a 1/4 wave whip at 2m too.).
> > > > >
> > > > > So, next version of APRStk will be able to tune the radio to the right
> > > > > satellite and tune for doppler.  Then just hooking the output to a TELNET
> > > > > port can combine/share the downlink with other similar stations and the
> > > > > world.
> > > > >
> > > > > Then all we need is 5 more such sites and we have the whole USA covered.
> > > > > Every packet from the satellite gets collected... and shared via the
> > > > > TELNET links between the sites...
> > > > >
> > > > > To see what we can do with this for a mobile amateur radio:
> > > > >
> > > > >   http://web.usna.navy.mil/~bruninga/astars.html
> > > > >
> > > > > de WB4APR, Bob
> > > > >
> > > > > Yes, this works well in your car.  But if you put 50 feet of coax between
> > > > > the antenna and the HT in your shack, then you just lost 3 dB and should
> > > > > add a preamp...(at the antenna).
> > > > >
> > > > > ----
> > > > > Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> > > > > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > > APRSdos REPLY/COMMENT:
> > >
> > > Reply mail addr:   wb4apr@amsat.org
> > > US mail address:   115 old Farm Ct, Glen Burnie, MD 21060
> > > See DAYTON97 HISTORY:    http://web.usna.navy.mil/~bruninga/dayton.html
> > > See Maryland APRS LIVE:  http://web.usna.navy.mil/~bruninga/aprs.html
> > > See GPS on ANY radio:    http://www.tapr.org/tapr/html/mic-e.html
> > >
> > > ----
> > > Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> > > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
> >
> >
> >
>
> APRSdos REPLY/COMMENT:
>
> Reply mail addr:   wb4apr@amsat.org
> US mail address:   115 old Farm Ct, Glen Burnie, MD 21060
> See DAYTON97 HISTORY:    http://web.usna.navy.mil/~bruninga/dayton.html
> See Maryland APRS LIVE:  http://web.usna.navy.mil/~bruninga/aprs.html
> See GPS on ANY radio:    http://www.tapr.org/tapr/html/mic-e.html
>
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org

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