[amsat-bb] Re: Dual Hop and RAFT

Tue Apr 3 05:12:19 PDT 2007

Maybe RAFT got reset?  If its telemetry packets are every 10
seconds, then it is still set for digipeat.  If it has fallen
back to 1 minute rate, then digi is disabled.  Ill check...
http://pcsat.aprs.org ...

Yep, it is at 1 minute rate and needs a reload...

Ill send out an announcement to all command stations.

Bob

> -----Original Message-----
> From: Sil - ZL2CIA [mailto:zl2cia at amsat.org] 
> Sent: Tuesday, April 03, 2007 3:18 AM
> To: bruninga at usna.edu
> Cc: 'AMSAT'
> Subject: Re: [amsat-bb] Re: Dual Hop
> 
> Bob,
> 
> Thanks for your reply. I had the chance to make 
> another attempt at a dual hop this afternoon. 
> While I could copy both satellite beacons, I was 
> not successful in making a dual hop. I used the 
> path "via ARISS ARISS SGATE". It was fun to see 
> the interleaved beacons and digipeated messages 
> appearing on my screen (copied traffic was s-gated).
> 
> Tellingly, only ANDE repeated my packets. Until 
> now, almost all the passes I have worked have been 
> in the evening and I have had no problems getting 
> traffic through RAFT..
> 
> I haven't had the opportunity to work NO60 and 
> NO61 in the past few days, family taking precedence.
> 
> However, I will make some careful observations 
> over the next few days and provide an assessment 
> for you.
> 
> Unfortunately, I don't have a great QTH for 
> horizon satellite work. I live in a small valley 
> on the side of one of this cities many hills and 
> these raise my effective horizon.
> 
> Sil - ZL2CIA
> 
> 
> Robert Bruninga wrote:
> >>The ANDE & RAFT satellites maybe be a little 
> >>difficult with simple omnidirectional antennas, 
> >>but both are a breeze with just a little more antenna.
> > 
> > 
> > Sil,  Thanks for the report.
> > Do not worry about ANDE usage.  It is well below
anticipated, so
> > we are not woried about life.  But this week both are
entering
> > night time prime-time in the northern hemisphere and so
usage
> > will increase.
> > 
> > Also, I do want your assessment of their links.  My rig is
22
> > elements cross polarized on AZ/EL mount with 100W amp/preamp
at
> > base fed from 150' of coax.  I have not changed it in years,
> > since I get the same performance to a VHF DX beacon about 30
> > miles away...
> > 
> > BUT... 1) The preamp is not really a low noise one, just one
of
> > those in a 100W remote PA to overcome some coax loss.  2) I
> > suspect my deviation setting could be tweaked...
> > 
> > My results are:
> > 1) I cannot access RAFT below 20 degrees and never in the
day
> > (due to overvoltage)
> > 2) I can decode RAFT above about 10 deg, and some times all
the
> > way to 1 deg if lucky 
> > 3) ANDE is also about 10 deg but sometimes lower.
> > 
> > If you get better performance, let me know, since I want to
know
> > how my performance is relative to other setups..  I measure
> > performance relative to elevation angle, because that is a
> > direct correlation to range.
> > 
> > Thanks
> > Bob
> > 
> > 
> > 
> >>-----Original Message-----
> >>From: Sil - ZL2CIA [mailto:zl2cia at amsat.org] 
> >>Sent: Friday, March 30, 2007 12:16 AM
> >>To: bruninga at usna.edu; AMSAT
> >>Subject: Re: [amsat-bb] Dual Hop
> >>
> >>
> >>>
> >>>Actually, they are intentinoally on the same frequency and
> > 
> > they
> > 
> >>>are intended to be dual or even triple hop possible (when
> >>>PCSAT-1 is working)..  Notice that both satelites respond
to
> > 
> > the
> > 
> >>>same path VIA ARISS.  SO you could use the path VIA
> > 
> > ARISS,ARISS
> > 
> >>>and get a dual hop.  This ia also why we invite any other
> >>>university or amateur satellite builder to add more
> > 
> > spacecraft
> > 
> >>>on this 1200 baud relay channel (with IARU coordination of
> >>>course).
> >>>
> >>
> >>Bob,
> >>
> >>Thanks for your reply.
> >>
> >>I have already tried "via APRSAT,APRSAT,SGATE a 
> >>number of times, but so far without successs. I 
> >>wasn't sure if this was an acceptable practice, so 
> >>I had been discrete about it.
> >>
> >>I have been previously successful once getting a 
> >>dual hop between PCSAT-1 and the ISS (when it was 
> >>operating on 145.825 MHz)
> >>
> >>The ANDE & RAFT satellites maybe be a little 
> >>difficult with simple omnidirectional antennas, 
> >>but both are a breeze with just a little more antenna.
> >>
> >>I use nothing more than a horizontally polarised 6 
> >>element beam. It's home built and that without any 
> >>fancy tools. It's horizontally mounted and 
> >>steerable in azimuth with a simple rotator. I 
> >>mention this just to make the point that both are 
> >>really pretty easy satellites to work with just a 
> >>little more antenna.
> >>
> >>Both satellites are very quiet down here and I 
> >>very seldom see any other users. I end up gating 
> >>my own packets. This does allow me to experiment 
> >>since I'm not obstructing anyone else.
> >>
> >>I'll persevere with further dual hop tests in the 
> >>future now that I understand it's okay to do so.
> >>
> >>I am of course aware of ANDE-1's rather finite 
> >>power reserve and do keep that in mind.
> >>
> >>Sil
> >>
> >>
> > 
> > 
> > _______________________________________________
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> of the author.
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> 