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:
- 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@amsat.org] Sent: Friday, March 30, 2007 12:16 AM To: bruninga@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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