| |
CX2SA > SATDIG 17.04.17 02:55l 1411 Lines 47289 Bytes #999 (0) @ WW
BID : AMSATBB12103
Read: GUEST
Subj: AMSAT-BB-digest V12 103
Path: IW8PGT<IZ3LSV<DB0ERF<OK0NAG<OK0NBR<F3KT<CX2SA
Sent: 170417/0043Z @:CX2SA.SAL.URY.SOAM #:5182 [Salto] FBB7.00e $:AMSATBB12103
From: CX2SA@CX2SA.SAL.URY.SOAM
To : SATDIG@WW
Today's Topics:
1. Re: Thoughts on ISS packet switch back to 145.825 MHz (long)
(Kevin M)
2. Re: Thoughts on ISS packet switch back to 145.825 MHz (long)
(Stefan Wagener)
3. Re: Thoughts on ISS packet switch back to 145.825 MHz (long)
(Stefan Wagener)
4. Re: Thoughts on ISS packet switch back to 145.825 MHz (long)
(Matthew Stevens)
5. Re: Thoughts on ISS packet switch back to 145.825 MHz (long)
(John Becker)
6. Re: Thoughts on ISS packet switch back to 145.825 MHz (long)
(Gabriel Zeifman)
----------------------------------------------------------------------
Message: 1
Date: Mon, 17 Apr 2017 00:05:17 +0000 (UTC)
From: Kevin M <n4ufo@xxxxx.xxx>
To: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] Thoughts on ISS packet switch back to 145.825
MHz (long)
Message-ID: <513412946.1411614.1492387517017@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Well, if that's what you believe and a logical argument based on similar
experience isn't convincing enough, I suppose only 'proof' will do. But I
don't have any 'proof' in hand and my experiences are merely similar, so a
trip to a tower transmitter site won't be effective in this case. I wonder
if it's possible to get the astronauts to make a recording of the receiver
audio and send it to the ground by other means. X^D? <this is sarcasm and
humor for anyone not getting it...>
Good luck!
From: Stefan Wagener <wageners@xxxxx.xxx> To: Kevin M <n4ufo@xxxxx.xxx>
Cc: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Sent: Sunday, April 16, 2017 7:25 PM
Subject: Re: [amsat-bb] Thoughts on ISS packet switch back to 145.825 MHz
(long)
Thanks Kevin,
I appreciate your insight and experience. Thanks for your work as a
statewide packet coordinator. That is great!
I just worked the last ISS pass 20 min ago and the ISS radio was silent for
20 sec+ in between most packets. NO, I do not believe that the cause is
colliding packets, since I can fire off rapid packets and they get repeated
quickly, if I choose to and NO, no one has ever told me that I create QRM
:-)? Traffic was low on the last pass. Made three contacts easily.
Hope that helps,
Stefan
On Sun, Apr 16, 2017 at 6:00 PM, Kevin M via AMSAT-BB <amsat-bb@xxxxx.xxx>
wrote:
> No, you are not creating QRM if the ISS does not repeat your packet.
Listen to the path of the ISS and
> you will hear that 50% of the time the radio is silent. It does not TX
since there are no valid packets.
> Where is the QRM?
I don't have a dog in this fight since I don't work packet any more... but
at one time I was a statewide packet coordinator and personally took care of
numerous dual band packet nodes. I've listened to the audio while at those
sites. There may be one thing to consider than a regular 'ground op' doesn't
think of...
At high altitude, the receiver can hear a LOT and there are a lot of packets
that do not get decoded because two, three, even four or more stations will
all transmit at once and cover some part of another stations packet, thereby
negating each other. (FM capture effect does not really apply for packet
unless it's near 100% with clear audio, which is rare.) Because those
stations are not hearing each other, they will key up and transmit at will,
whether another station is transmitting at the time or not. From the
'digipeaters' point of view, it hears only partial packets, with lots of
overlapping signals, so it decodes none.
Whether or not the activity is appropriate, I'm not commenting on that...
but I'm addressing your question so that you can better decide for yourself
that question. My answer to 'where is the QRM?' is... 'The radio is silent
50% of the time, because it cannot decode enough valid packets... true. But
the reason it can't decode enough valid packets may well be (and most likely
IS) that all the transmitting stations continually overlap each other. (QRM
each other)' The error in the logic here is assuming that it doesn't
retransmit because it doesn't 'hear'... On the contrary, it HEARS TOO MUCH
and can't make sense of the mess to decode it. In other words, it manages to
hear a packet in the clear, about 50% of the time.
In simple terms, it's most likely silent BECAUSE of the QRM... as opposed to
the silence being an indicator of a LACK of QRM as you have suggested. Which
would be no different than SO-50 staying silent because 3-4 stations are all
keying up at once and SO-50 can't make sense enough to decode someone's PL
tone. In both cases... too many stations, bird can't hear... bird does not
retransmit.
73 and good luck to all in finding a workable solution.? Kevin N4UFO
?
______________________________ _________________
Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
to all interested persons worldwide without requiring membership. Opinions
expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://www.amsat.org/mailman/ listinfo/amsat-bb
------------------------------
Message: 2
Date: Sun, 16 Apr 2017 19:10:20 -0500
From: Stefan Wagener <wageners@xxxxx.xxx>
To: Jim Walls <jim@xxxxx.xxx>
Cc: AMSAT BB <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] Thoughts on ISS packet switch back to 145.825
MHz (long)
Message-ID:
<CAKu8kHD0p4Di8imC0vxq49K_wzv=WUNbNvHWWRxao8J_XB1Cjw@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Thanks Jim,
I actually don't miss the point. The "Common Problem" is not the lack of
activity on the ISS (colliding packets), the problem is the unattended
digipeating stations therefor by definition, the downlink signal everyone
is hearing. Otherwise you wouldn't know that they are there:-) As I said
before lets point them out and deal with it.
I just have a hard time with someone claiming universally the 'golden rule"
on the ISS (and again and again I am not talking about the SO-50's of the
world). I encourage and will encourage folks to experiment with the ISS,
trying to to get their packets through even if they don't get their own
packets decoded on their side. This is what amateur radio is all about,
trying to discover new ways .... Throwing the "book" at folks is not me.
Rest my case, Stefan VE4NSA
On Sun, Apr 16, 2017 at 6:30 PM, Jim Walls <jim@xxxxx.xxx> wrote:
> Stefan,
> I think you are the one missing the point. QRM on almost any satellite
> path is on the uplink, not the downlink. This is particularly true for
> modes that allow only one station to transmit at a time (specifically
> including packet). If more than one person transmits on the uplink wherein
> their transmissions overlap, neither is properly decoded by the ISS, so
> nothing is transmitted by the ISS. If this continues for the entire pass,
> there will never be any downlink transmissions. By your definition, there
> was no QRM (because you could not hear it - but the ISS did), and you
> encourage more stations to transmit - thereby making the problem even worse.
>
> Jim Walls
> K6CCC
>
>
>
> On 4/16/2017 15:18, Stefan Wagener wrote:
>
>> Thanks Mike,
>>
>> Again, you don't seem to get the point. Based on your setup, TNC, software
>> etc you will NOT be able to decode every single packet and based on your
>> setup and the ISS position the ISS digipeater will not re-transmit. It's
>> the nature of the beast. No, you are not creating QRM if the ISS does not
>> repeat your packet. Listen to the path of the ISS and you will hear that
>> 50% of the time the radio is silent. It does not TX since there are no
>> valid packets. Where is the QRM? There is none other than in you local
>> environment where nobody cares. Don't discourage those that are trying to
>> make it work. If you want a case, point out the stations and callsigns
>> that
>> create QRM and are not listenting/responding!
>>
>> Just check out the last pass over the US. You will find 10 stations,
>> that's
>> a station a minute with room to spare. This is NOT SO-50!
>>
>> 73, Stefan, VE4NSA
>>
>>
>>
>> On Sun, Apr 16, 2017 at 5:05 PM, Mike Diehl <diehl.mike.a@xxxxx.xxx>
>> wrote:
>>
>> Stefan,
>>>
>>> I think you're taking Gabe's comment too literal. The point he's trying
>>> to
>>> make is that many stations just keep on transmitting when they can't hear
>>> anything.
>>>
>>> We can use that amateur radio on ISS as an experiment as an excuse but
>>> that doesn't really fly. APRS is beyond an experiment as it is a well
>>> established form of using APRS via satellite, nothing new here.
>>>
>>> Furthermore, what is the point of trying repeatedly to transmit if you
>>> can't decode? It is the golden rule for a reason and it applies
>>> everywhere,
>>> satellite or terrestrial. If you can't hear it you can't work it, bottom
>>> line. Until you can decode packets you're just creating QRM.
>>>
>>> 73,
>>>
>>> Mike Diehl
>>> AI6GS
>>>
>>> On Apr 16, 2017, at 2:46 PM, Stefan Wagener <wageners@xxxxx.xxx> wrote:
>>>>
>>>> Hi Gabe,
>>>>
>>>> With all respect I very much disagree. The amateur radio equipment on
>>>> the
>>>> ISS is an experiment! Sometimes it works and sometimes it doesn't. Based
>>>>
>>> on
>>>
>>>> your location, equipment and ISS position you will* NOT* decode every
>>>> packet, and yes that includes your own packets. So folks will be trying
>>>> again and that's okay. *They don't become a source of QRM* on the ISS
>>>>
>>> since
>>>
>>>> the ISS will only re-transmit if its a good packet. They are exercising
>>>> their license privileges to work through the ISS and for many having
>>>> that
>>>> first digipeat after many tries is their success story and we welcome
>>>>
>>> that.
>>>
>>>> 73, Stefan, VE4NSA
>>>>
>>>>
>>>>
>>>> On Sun, Apr 16, 2017 at 1:43 PM, Gabriel Zeifman <
>>>>
>>> gabrielzeifman@xxxxx.xxx>
>>>
>>>> wrote:
>>>>
>>>> I think the golden rule of working all sats applies to ISS as well: if
>>>>>
>>>> you
>>>
>>>> can't hear (or decode), don't transmit! It's easy to become a source of
>>>>>
>>>> QRM
>>>
>>>> if you keep transmitting in the blind when you can't hear.
>>>>>
>>>>> 73,
>>>>> Gabe
>>>>> NJ7H
>>>>>
>>>>> On Apr 16, 2017, at 1:28 PM, Robert Bruninga <bruninga@xxxx.xxx>
>>>>>>
>>>>> wrote:
>>>
>>>> I agree completely. ISS digipeting should be for LIVE operators. Or
>>>>>>
>>>>> for
>>>
>>>> LIVE things.... (a student experimental ocean going buoy for
>>>>>>
>>>>> example)...
>>>
>>>> NOT for non-moving-fixed egos...
>>>>>>
>>>>>> Bob, WB4APR
>>>>>>
>>>>>> -----Original Message-----
>>>>>> From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of
>>>>>>
>>>>> Patrick
>>>
>>>> STODDARD (WD9EWK/VA7EWK)
>>>>>> Sent: Saturday, April 15, 2017 7:51 PM
>>>>>> To: amsat-bb@xxxxx.xxx
>>>>>> Subject: [amsat-bb] Thoughts on ISS packet switch back to 145.825 MHz
>>>>>> (long)
>>>>>>
>>>>>> Hi!
>>>>>>
>>>>>> Earlier today, I tweeted a quick comment about what I saw on the ISS
>>>>>> 145.825 MHz digipeater just after 1900 UTC this afternoon. Since
>>>>>> tweets
>>>>>> are limited in length, I'm posting a longer message here...
>>>>>>
>>>>>> In the past few weeks, once word got out that a replacement for the
>>>>>>
>>>>> failed
>>>>>
>>>>>> Ericsson VHF HT on the ISS was being sent up to the station, many were
>>>>>> anxiously looking forward to seeing the ISS digipeater move from
>>>>>>
>>>>> 437.550
>>>
>>>> MHz back to 145.825 MHz, where it had been until the old radio's
>>>>>>
>>>>> failure
>>>
>>>> in mid-October 2016. I understood that many would welcome this change,
>>>>>>
>>>>> but
>>>>>
>>>>>> I was not jumping up and down with excitement. Unfortunately, after
>>>>>>
>>>>> seeing
>>>>>
>>>>>> the activity on the ISS digipeater in the past day or so since the
>>>>>> replacement VHF radio was put on 145.825 MHz, my worries have been
>>>>>> confirmed.
>>>>>>
>>>>>> For many, the move to 437.550 MHz meant many stations that could
>>>>>> easily
>>>>>> work 145.825 MHz would have to change. Whether it was a different
>>>>>>
>>>>> antenna
>>>
>>>> for the 70cm band or dealing with Doppler with the 437.550 MHz
>>>>>>
>>>>> frequency,
>>>
>>>> almost all of the unattended stations that had been present on the
>>>>>>
>>>>> 145.825
>>>>>
>>>>>> MHz frequency were gone. If you wanted to use the ISS digipeater to
>>>>>>
>>>>> work
>>>
>>>> other stations, this was a great opportunity. Many stations using
>>>>>> APRS-ready HTs and mobile transceivers were showing up, using a group
>>>>>>
>>>>> of
>>>
>>>> memory channels to compensate for Doppler, and were making contacts.
>>>>>>
>>>>> Some
>>>
>>>> fixed stations, including those already capable of satellite operating,
>>>>>> were also showing up. Even on the busier passes, the
>>>>>> 437.550 MHz always seemed to be clear of the clutter from the
>>>>>>
>>>>> unattended
>>>
>>>> stations that previously inhabited 145.825 MHz.
>>>>>>
>>>>>> Fast forward to yesterday (Friday, 14 April). The ISS digipeater
>>>>>>
>>>>> switched
>>>
>>>> to 145.825 MHz in time for afternoon/evening passes over Europe (around
>>>>>> 1330-1400 UTC). Lots of stations showed up, based on looking at the
>>>>>> ariss.net web site. The same thing started to happen here in North
>>>>>> America, later in the day. The passes I worked last night were not
>>>>>> bad,
>>>>>> but there were more stations on one pass that went over much of the
>>>>>> continental USA than I'd typically see on 437.550 MHz.
>>>>>>
>>>>>> By midday today (1900 UTC), it seemed like many more stations were on
>>>>>>
>>>>> the
>>>
>>>> frequency. I saw 11 other call signs on a pass just after that time
>>>>>>
>>>>> this
>>>
>>>> afternoon. At best, there may have been 4 or 5 other operators at their
>>>>>> keyboards or keypads, looking to make contacts.
>>>>>> The others were just squawking away, not answering APRS messages sent
>>>>>>
>>>>> to
>>>
>>>> them. By the time the ISS footprint was reaching the east coast, the
>>>>>> frequency was congested. Lots of position beacons were coming through,
>>>>>>
>>>>> but
>>>>>
>>>>>> not much of anything else. This is not new; Clayton W5PFG wrote about
>>>>>>
>>>>> this
>>>>>
>>>>>> about a year ago, here on the AMSAT-BB list:
>>>>>>
>>>>>> http://amsat.org/pipermail/amsat-bb/2016-April/058200.html
>>>>>>
>>>>>> For the two passes I worked this afternoon, around 1900 and 2035 UTC,
>>>>>> I
>>>>>> made two QSOs on the earlier pass, and one on the later pass. A shame,
>>>>>> considering there were so many other call signs on the earlier pass,
>>>>>>
>>>>> and
>>>
>>>> even some rare spots - stations in DM44 in northern Arizona and CM86 in
>>>>>> Santa Cruz CA were seen.
>>>>>>
>>>>>> It is interesting that hams want to have their stations squawk on
>>>>>> 145.825 MHz when nobody is at the keyboard. It could be doing it 24/7,
>>>>>>
>>>>> no
>>>
>>>> matter if the ISS is in view or not. Would anyone think of setting up
>>>>>> their satellite station to automatically transmit their call sign and
>>>>>> location every 15/30/60 seconds to SO-50, unattended? I think not!
>>>>>> That
>>>>>> could be a violation of the regulations, and would definitely be poor
>>>>>>
>>>>> form
>>>>>
>>>>>> by that operator.
>>>>>>
>>>>>> Bob Bruninga WB4APR has a couple of documents with recommendations for
>>>>>> beacon intervals when working the ISS digipeater. One mentioned a
>>>>>>
>>>>> 5-minute
>>>>>
>>>>>> interval for unattended stations:
>>>>>>
>>>>>> http://www.aprs.org/iss-aprs/iss-tx.txt
>>>>>>
>>>>>> Another document recommends that unattended stations should be in
>>>>>>
>>>>> "receive
>>>>>
>>>>>> ONLY mode." (emphasis is Bob's):
>>>>>>
>>>>>> http://www.aprs.org/iss-aprs/utiquet.txt
>>>>>>
>>>>>> I agree with the latter. If your station is unattended, why have it
>>>>>> transmit at all?! It may be different for less-populated parts of the
>>>>>> world, where gateway stations may transmit and then receive their
>>>>>>
>>>>> beacons
>>>
>>>> from the ISS, which will show up on ariss.net and other sites. For
>>>>>>
>>>>> Europe,
>>>>>
>>>>>> and definitely North America, the gateways really don't need to
>>>>>>
>>>>> transmit
>>>
>>>> if they are unattended. There should be activity on most passes, maybe
>>>>>> even late into the night, to know 145.825 MHz on the ISS is up and
>>>>>> running.
>>>>>>
>>>>>> Please don't misunderstand me... I think it is great for hams to set
>>>>>> up
>>>>>> gateway stations listening on 145.825 MHz for the space-borne APRS
>>>>>> activity (ISS, NO-84, even NO-44 when it gets enough power to transmit
>>>>>> complete packets). But these stations, like other stations that aren't
>>>>>> operating as gateways yet transmit automatically, shouldn't contribute
>>>>>>
>>>>> to
>>>
>>>> the congestion on the frequency.
>>>>>>
>>>>>> I know I am in the minority on the ISS digipeater moving back to
>>>>>> 145.825 MHz. Between the unattended stations clogging up the frequency
>>>>>>
>>>>> and
>>>>>
>>>>>> some local interference I hear on 145.825 MHz around my house, having
>>>>>>
>>>>> the
>>>
>>>> ISS on 437.550 MHz was fun! I worked it from home, and on some of my
>>>>>>
>>>>> road
>>>
>>>> trips in the past 5+ months. Even for some of my last NPOTA activations
>>>>>>
>>>>> at
>>>>>
>>>>>> the end of 2016. I'll continue to work the ISS digipeater, almost
>>>>>> exclusively with my APRS-ready HTs (TH-D72A, or TH-D74A), looking to
>>>>>>
>>>>> make
>>>
>>>> QSOs by exchanging APRS messages with other stations. If you can work
>>>>>> packet from your station, and we are in the same footprints, I hope to
>>>>>> hear you (and see you on my screen) soon. Like W5PFG mentioned a year
>>>>>>
>>>>> ago,
>>>>>
>>>>>> let's get more stations on 145.825 MHz making QSOs...
>>>>>>
>>>>>> 73!
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> Patrick WD9EWK/VA7EWK
>>>>>> http://www.wd9ewk.net/
>>>>>> Twitter: @xxxxxx
>>>>>> _______________________________________________
>>>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
>>>>>>
>>>>> to
>>>
>>>> all interested persons worldwide without requiring membership. Opinions
>>>>>> expressed are solely those of the author, and do not reflect the
>>>>>>
>>>>> official
>>>
>>>> views of AMSAT-NA.
>>>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
>>>>>>
>>>>> program!
>>>>>
>>>>>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>>>>>> _______________________________________________
>>>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
>>>>>> to all interested persons worldwide without requiring membership.
>>>>>>
>>>>> Opinions expressed
>>>>>
>>>>>> are solely those of the author, and do not reflect the official views
>>>>>>
>>>>> of
>>>
>>>> AMSAT-NA.
>>>>>
>>>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
>>>>>>
>>>>> program!
>>>>>
>>>>>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>>>>>>
>>>>> _______________________________________________
>>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
>>>>> to all interested persons worldwide without requiring membership.
>>>>>
>>>> Opinions
>>>
>>>> expressed
>>>>> are solely those of the author, and do not reflect the official views
>>>>> of
>>>>> AMSAT-NA.
>>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
>>>>>
>>>> program!
>>>
>>>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>>>>>
>>>>> _______________________________________________
>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
>>>> to all interested persons worldwide without requiring membership.
>>>>
>>> Opinions expressed
>>>
>>>> are solely those of the author, and do not reflect the official views of
>>>>
>>> AMSAT-NA.
>>>
>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
>>>>
>>> program!
>>>
>>>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>>>>
>>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
>> to all interested persons worldwide without requiring membership.
>> Opinions expressed
>> are solely those of the author, and do not reflect the official views of
>> AMSAT-NA.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>>
>>
>
> --
> 73
> -------------------------------------
> Jim Walls - K6CCC
> jim@xxxxx.xxx
> Ofc: 818-548-4804
> http://members.dslextreme.com/users/k6ccc/
> AMSAT Member 32537 - WSWSS Member 395
>
>
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 3
Date: Sun, 16 Apr 2017 19:14:54 -0500
From: Stefan Wagener <wageners@xxxxx.xxx>
To: Kevin M <n4ufo@xxxxx.xxx>
Cc: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] Thoughts on ISS packet switch back to 145.825
MHz (long)
Message-ID:
<CAKu8kHDQ6_fhh-nFFYVtFYw+yU0_FySUcpNptdArJ-S-Xuj3JQ@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Thanks Kevin,
Respectfully, we have to agree to disagree.
73, Stefan, VE4NSA
On Sun, Apr 16, 2017 at 7:05 PM, Kevin M via AMSAT-BB <amsat-bb@xxxxx.xxx>
wrote:
> Well, if that's what you believe and a logical argument based on similar
> experience isn't convincing enough, I suppose only 'proof' will do. But I
> don't have any 'proof' in hand and my experiences are merely similar, so a
> trip to a tower transmitter site won't be effective in this case. I wonder
> if it's possible to get the astronauts to make a recording of the receiver
> audio and send it to the ground by other means. X^D <this is sarcasm and
> humor for anyone not getting it...>
>
> Good luck!
>
>
>
>
>
>
> From: Stefan Wagener <wageners@xxxxx.xxx> To: Kevin M <n4ufo@xxxxx.xxx>
> Cc: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
> Sent: Sunday, April 16, 2017 7:25 PM
> Subject: Re: [amsat-bb] Thoughts on ISS packet switch back to 145.825 MHz
> (long)
>
> Thanks Kevin,
>
> I appreciate your insight and experience. Thanks for your work as a
> statewide packet coordinator. That is great!
>
> I just worked the last ISS pass 20 min ago and the ISS radio was silent
> for 20 sec+ in between most packets. NO, I do not believe that the cause is
> colliding packets, since I can fire off rapid packets and they get repeated
> quickly, if I choose to and NO, no one has ever told me that I create QRM
> :-) Traffic was low on the last pass. Made three contacts easily.
>
> Hope that helps,
>
> Stefan
>
>
>
>
>
> On Sun, Apr 16, 2017 at 6:00 PM, Kevin M via AMSAT-BB <amsat-bb@xxxxx.xxx>
> wrote:
>
> > No, you are not creating QRM if the ISS does not repeat your packet.
> Listen to the path of the ISS and
> > you will hear that 50% of the time the radio is silent. It does not TX
> since there are no valid packets.
> > Where is the QRM?
>
>
> I don't have a dog in this fight since I don't work packet any more... but
> at one time I was a statewide packet coordinator and personally took care
> of numerous dual band packet nodes. I've listened to the audio while at
> those sites. There may be one thing to consider than a regular 'ground op'
> doesn't think of...
>
>
> At high altitude, the receiver can hear a LOT and there are a lot of
> packets that do not get decoded because two, three, even four or more
> stations will all transmit at once and cover some part of another stations
> packet, thereby negating each other. (FM capture effect does not really
> apply for packet unless it's near 100% with clear audio, which is rare.)
> Because those stations are not hearing each other, they will key up and
> transmit at will, whether another station is transmitting at the time or
> not. From the 'digipeaters' point of view, it hears only partial packets,
> with lots of overlapping signals, so it decodes none.
>
>
> Whether or not the activity is appropriate, I'm not commenting on that...
> but I'm addressing your question so that you can better decide for yourself
> that question. My answer to 'where is the QRM?' is... 'The radio is silent
> 50% of the time, because it cannot decode enough valid packets... true. But
> the reason it can't decode enough valid packets may well be (and most
> likely IS) that all the transmitting stations continually overlap each
> other. (QRM each other)' The error in the logic here is assuming that it
> doesn't retransmit because it doesn't 'hear'... On the contrary, it HEARS
> TOO MUCH and can't make sense of the mess to decode it. In other words, it
> manages to hear a packet in the clear, about 50% of the time.
>
>
> In simple terms, it's most likely silent BECAUSE of the QRM... as opposed
> to the silence being an indicator of a LACK of QRM as you have suggested.
> Which would be no different than SO-50 staying silent because 3-4 stations
> are all keying up at once and SO-50 can't make sense enough to decode
> someone's PL tone. In both cases... too many stations, bird can't hear...
> bird does not retransmit.
>
>
> 73 and good luck to all in finding a workable solution. Kevin N4UFO
>
> ______________________________ _________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/ listinfo/amsat-bb
>
>
>
>
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 4
Date: Sun, 16 Apr 2017 20:19:23 -0400
From: Matthew Stevens <matthew@xxxxxxxxx.xxx>
To: Stefan Wagener <wageners@xxxxx.xxx>
Cc: AMSAT BB <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] Thoughts on ISS packet switch back to 145.825
MHz (long)
Message-ID:
<CAN8zKtSOn_3hKpszABXY2sRsosqDL+edkHTionALe16qbOqqfw@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Um. I think all anyone was saying is (as is good practice on any sat,
actually anything in ham radio) - listen before you transmit. "Listening"
in the case of the APRS sats can be either waiting for a minute or two to
see if you decode anything (including the beacon), or literally just
turning the squelch off on your rig and listening for packet transmissions
by ear. If you're hearing no activity by ear, and/or decoding the beacon
but nothing else, great! Maybe it's just a slow pass.
If you're hearing multiple transmissions by ear, but not getting any
decodes (including the beacon) - maybe you have an issue with your RX and
you should address that before transmitting. Otherwise you risk both QRMing
other QSOs in progress, and/or having others attempt to respond to you and
you won't be able to decode their packets.
Just listen first, then transmit. That's the "golden rule" of any ham radio
activity, not just sats or ISS digi.
?73?
- Matthew
? kk4fem?
On Sun, Apr 16, 2017 at 8:10 PM, Stefan Wagener <wageners@xxxxx.xxx> wrote:
> Thanks Jim,
>
> I actually don't miss the point. The "Common Problem" is not the lack of
> activity on the ISS (colliding packets), the problem is the unattended
> digipeating stations therefor by definition, the downlink signal everyone
> is hearing. Otherwise you wouldn't know that they are there:-) As I said
> before lets point them out and deal with it.
>
> I just have a hard time with someone claiming universally the 'golden rule"
> on the ISS (and again and again I am not talking about the SO-50's of the
> world). I encourage and will encourage folks to experiment with the ISS,
> trying to to get their packets through even if they don't get their own
> packets decoded on their side. This is what amateur radio is all about,
> trying to discover new ways .... Throwing the "book" at folks is not me.
>
> Rest my case, Stefan VE4NSA
>
>
>
> On Sun, Apr 16, 2017 at 6:30 PM, Jim Walls <jim@xxxxx.xxx> wrote:
>
> > Stefan,
> > I think you are the one missing the point. QRM on almost any satellite
> > path is on the uplink, not the downlink. This is particularly true for
> > modes that allow only one station to transmit at a time (specifically
> > including packet). If more than one person transmits on the uplink
> wherein
> > their transmissions overlap, neither is properly decoded by the ISS, so
> > nothing is transmitted by the ISS. If this continues for the entire
> pass,
> > there will never be any downlink transmissions. By your definition,
> there
> > was no QRM (because you could not hear it - but the ISS did), and you
> > encourage more stations to transmit - thereby making the problem even
> worse.
> >
> > Jim Walls
> > K6CCC
> >
> >
> >
> > On 4/16/2017 15:18, Stefan Wagener wrote:
> >
> >> Thanks Mike,
> >>
> >> Again, you don't seem to get the point. Based on your setup, TNC,
> software
> >> etc you will NOT be able to decode every single packet and based on your
> >> setup and the ISS position the ISS digipeater will not re-transmit. It's
> >> the nature of the beast. No, you are not creating QRM if the ISS does
> not
> >> repeat your packet. Listen to the path of the ISS and you will hear that
> >> 50% of the time the radio is silent. It does not TX since there are no
> >> valid packets. Where is the QRM? There is none other than in you local
> >> environment where nobody cares. Don't discourage those that are trying
> to
> >> make it work. If you want a case, point out the stations and callsigns
> >> that
> >> create QRM and are not listenting/responding!
> >>
> >> Just check out the last pass over the US. You will find 10 stations,
> >> that's
> >> a station a minute with room to spare. This is NOT SO-50!
> >>
> >> 73, Stefan, VE4NSA
> >>
> >>
> >>
> >> On Sun, Apr 16, 2017 at 5:05 PM, Mike Diehl <diehl.mike.a@xxxxx.xxx>
> >> wrote:
> >>
> >> Stefan,
> >>>
> >>> I think you're taking Gabe's comment too literal. The point he's trying
> >>> to
> >>> make is that many stations just keep on transmitting when they can't
> hear
> >>> anything.
> >>>
> >>> We can use that amateur radio on ISS as an experiment as an excuse but
> >>> that doesn't really fly. APRS is beyond an experiment as it is a well
> >>> established form of using APRS via satellite, nothing new here.
> >>>
> >>> Furthermore, what is the point of trying repeatedly to transmit if you
> >>> can't decode? It is the golden rule for a reason and it applies
> >>> everywhere,
> >>> satellite or terrestrial. If you can't hear it you can't work it,
> bottom
> >>> line. Until you can decode packets you're just creating QRM.
> >>>
> >>> 73,
> >>>
> >>> Mike Diehl
> >>> AI6GS
> >>>
> >>> On Apr 16, 2017, at 2:46 PM, Stefan Wagener <wageners@xxxxx.xxx>
> wrote:
> >>>>
> >>>> Hi Gabe,
> >>>>
> >>>> With all respect I very much disagree. The amateur radio equipment on
> >>>> the
> >>>> ISS is an experiment! Sometimes it works and sometimes it doesn't.
> Based
> >>>>
> >>> on
> >>>
> >>>> your location, equipment and ISS position you will* NOT* decode every
> >>>> packet, and yes that includes your own packets. So folks will be
> trying
> >>>> again and that's okay. *They don't become a source of QRM* on the ISS
> >>>>
> >>> since
> >>>
> >>>> the ISS will only re-transmit if its a good packet. They are
> exercising
> >>>> their license privileges to work through the ISS and for many having
> >>>> that
> >>>> first digipeat after many tries is their success story and we welcome
> >>>>
> >>> that.
> >>>
> >>>> 73, Stefan, VE4NSA
> >>>>
> >>>>
> >>>>
> >>>> On Sun, Apr 16, 2017 at 1:43 PM, Gabriel Zeifman <
> >>>>
> >>> gabrielzeifman@xxxxx.xxx>
> >>>
> >>>> wrote:
> >>>>
> >>>> I think the golden rule of working all sats applies to ISS as well: if
> >>>>>
> >>>> you
> >>>
> >>>> can't hear (or decode), don't transmit! It's easy to become a source
> of
> >>>>>
> >>>> QRM
> >>>
> >>>> if you keep transmitting in the blind when you can't hear.
> >>>>>
> >>>>> 73,
> >>>>> Gabe
> >>>>> NJ7H
> >>>>>
> >>>>> On Apr 16, 2017, at 1:28 PM, Robert Bruninga <bruninga@xxxx.xxx>
> >>>>>>
> >>>>> wrote:
> >>>
> >>>> I agree completely. ISS digipeting should be for LIVE operators. Or
> >>>>>>
> >>>>> for
> >>>
> >>>> LIVE things.... (a student experimental ocean going buoy for
> >>>>>>
> >>>>> example)...
> >>>
> >>>> NOT for non-moving-fixed egos...
> >>>>>>
> >>>>>> Bob, WB4APR
> >>>>>>
> >>>>>> -----Original Message-----
> >>>>>> From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of
> >>>>>>
> >>>>> Patrick
> >>>
> >>>> STODDARD (WD9EWK/VA7EWK)
> >>>>>> Sent: Saturday, April 15, 2017 7:51 PM
> >>>>>> To: amsat-bb@xxxxx.xxx
> >>>>>> Subject: [amsat-bb] Thoughts on ISS packet switch back to 145.825
> MHz
> >>>>>> (long)
> >>>>>>
> >>>>>> Hi!
> >>>>>>
> >>>>>> Earlier today, I tweeted a quick comment about what I saw on the ISS
> >>>>>> 145.825 MHz digipeater just after 1900 UTC this afternoon. Since
> >>>>>> tweets
> >>>>>> are limited in length, I'm posting a longer message here...
> >>>>>>
> >>>>>> In the past few weeks, once word got out that a replacement for the
> >>>>>>
> >>>>> failed
> >>>>>
> >>>>>> Ericsson VHF HT on the ISS was being sent up to the station, many
> were
> >>>>>> anxiously looking forward to seeing the ISS digipeater move from
> >>>>>>
> >>>>> 437.550
> >>>
> >>>> MHz back to 145.825 MHz, where it had been until the old radio's
> >>>>>>
> >>>>> failure
> >>>
> >>>> in mid-October 2016. I understood that many would welcome this change,
> >>>>>>
> >>>>> but
> >>>>>
> >>>>>> I was not jumping up and down with excitement. Unfortunately, after
> >>>>>>
> >>>>> seeing
> >>>>>
> >>>>>> the activity on the ISS digipeater in the past day or so since the
> >>>>>> replacement VHF radio was put on 145.825 MHz, my worries have been
> >>>>>> confirmed.
> >>>>>>
> >>>>>> For many, the move to 437.550 MHz meant many stations that could
> >>>>>> easily
> >>>>>> work 145.825 MHz would have to change. Whether it was a different
> >>>>>>
> >>>>> antenna
> >>>
> >>>> for the 70cm band or dealing with Doppler with the 437.550 MHz
> >>>>>>
> >>>>> frequency,
> >>>
> >>>> almost all of the unattended stations that had been present on the
> >>>>>>
> >>>>> 145.825
> >>>>>
> >>>>>> MHz frequency were gone. If you wanted to use the ISS digipeater to
> >>>>>>
> >>>>> work
> >>>
> >>>> other stations, this was a great opportunity. Many stations using
> >>>>>> APRS-ready HTs and mobile transceivers were showing up, using a
> group
> >>>>>>
> >>>>> of
> >>>
> >>>> memory channels to compensate for Doppler, and were making contacts.
> >>>>>>
> >>>>> Some
> >>>
> >>>> fixed stations, including those already capable of satellite
> operating,
> >>>>>> were also showing up. Even on the busier passes, the
> >>>>>> 437.550 MHz always seemed to be clear of the clutter from the
> >>>>>>
> >>>>> unattended
> >>>
> >>>> stations that previously inhabited 145.825 MHz.
> >>>>>>
> >>>>>> Fast forward to yesterday (Friday, 14 April). The ISS digipeater
> >>>>>>
> >>>>> switched
> >>>
> >>>> to 145.825 MHz in time for afternoon/evening passes over Europe
> (around
> >>>>>> 1330-1400 UTC). Lots of stations showed up, based on looking at the
> >>>>>> ariss.net web site. The same thing started to happen here in North
> >>>>>> America, later in the day. The passes I worked last night were not
> >>>>>> bad,
> >>>>>> but there were more stations on one pass that went over much of the
> >>>>>> continental USA than I'd typically see on 437.550 MHz.
> >>>>>>
> >>>>>> By midday today (1900 UTC), it seemed like many more stations were
> on
> >>>>>>
> >>>>> the
> >>>
> >>>> frequency. I saw 11 other call signs on a pass just after that time
> >>>>>>
> >>>>> this
> >>>
> >>>> afternoon. At best, there may have been 4 or 5 other operators at
> their
> >>>>>> keyboards or keypads, looking to make contacts.
> >>>>>> The others were just squawking away, not answering APRS messages
> sent
> >>>>>>
> >>>>> to
> >>>
> >>>> them. By the time the ISS footprint was reaching the east coast, the
> >>>>>> frequency was congested. Lots of position beacons were coming
> through,
> >>>>>>
> >>>>> but
> >>>>>
> >>>>>> not much of anything else. This is not new; Clayton W5PFG wrote
> about
> >>>>>>
> >>>>> this
> >>>>>
> >>>>>> about a year ago, here on the AMSAT-BB list:
> >>>>>>
> >>>>>> http://amsat.org/pipermail/amsat-bb/2016-April/058200.html
> >>>>>>
> >>>>>> For the two passes I worked this afternoon, around 1900 and 2035
> UTC,
> >>>>>> I
> >>>>>> made two QSOs on the earlier pass, and one on the later pass. A
> shame,
> >>>>>> considering there were so many other call signs on the earlier pass,
> >>>>>>
> >>>>> and
> >>>
> >>>> even some rare spots - stations in DM44 in northern Arizona and CM86
> in
> >>>>>> Santa Cruz CA were seen.
> >>>>>>
> >>>>>> It is interesting that hams want to have their stations squawk on
> >>>>>> 145.825 MHz when nobody is at the keyboard. It could be doing it
> 24/7,
> >>>>>>
> >>>>> no
> >>>
> >>>> matter if the ISS is in view or not. Would anyone think of setting up
> >>>>>> their satellite station to automatically transmit their call sign
> and
> >>>>>> location every 15/30/60 seconds to SO-50, unattended? I think not!
> >>>>>> That
> >>>>>> could be a violation of the regulations, and would definitely be
> poor
> >>>>>>
> >>>>> form
> >>>>>
> >>>>>> by that operator.
> >>>>>>
> >>>>>> Bob Bruninga WB4APR has a couple of documents with recommendations
> for
> >>>>>> beacon intervals when working the ISS digipeater. One mentioned a
> >>>>>>
> >>>>> 5-minute
> >>>>>
> >>>>>> interval for unattended stations:
> >>>>>>
> >>>>>> http://www.aprs.org/iss-aprs/iss-tx.txt
> >>>>>>
> >>>>>> Another document recommends that unattended stations should be in
> >>>>>>
> >>>>> "receive
> >>>>>
> >>>>>> ONLY mode." (emphasis is Bob's):
> >>>>>>
> >>>>>> http://www.aprs.org/iss-aprs/utiquet.txt
> >>>>>>
> >>>>>> I agree with the latter. If your station is unattended, why have it
> >>>>>> transmit at all?! It may be different for less-populated parts of
> the
> >>>>>> world, where gateway stations may transmit and then receive their
> >>>>>>
> >>>>> beacons
> >>>
> >>>> from the ISS, which will show up on ariss.net and other sites. For
> >>>>>>
> >>>>> Europe,
> >>>>>
> >>>>>> and definitely North America, the gateways really don't need to
> >>>>>>
> >>>>> transmit
> >>>
> >>>> if they are unattended. There should be activity on most passes, maybe
> >>>>>> even late into the night, to know 145.825 MHz on the ISS is up and
> >>>>>> running.
> >>>>>>
> >>>>>> Please don't misunderstand me... I think it is great for hams to set
> >>>>>> up
> >>>>>> gateway stations listening on 145.825 MHz for the space-borne APRS
> >>>>>> activity (ISS, NO-84, even NO-44 when it gets enough power to
> transmit
> >>>>>> complete packets). But these stations, like other stations that
> aren't
> >>>>>> operating as gateways yet transmit automatically, shouldn't
> contribute
> >>>>>>
> >>>>> to
> >>>
> >>>> the congestion on the frequency.
> >>>>>>
> >>>>>> I know I am in the minority on the ISS digipeater moving back to
> >>>>>> 145.825 MHz. Between the unattended stations clogging up the
> frequency
> >>>>>>
> >>>>> and
> >>>>>
> >>>>>> some local interference I hear on 145.825 MHz around my house,
> having
> >>>>>>
> >>>>> the
> >>>
> >>>> ISS on 437.550 MHz was fun! I worked it from home, and on some of my
> >>>>>>
> >>>>> road
> >>>
> >>>> trips in the past 5+ months. Even for some of my last NPOTA
> activations
> >>>>>>
> >>>>> at
> >>>>>
> >>>>>> the end of 2016. I'll continue to work the ISS digipeater, almost
> >>>>>> exclusively with my APRS-ready HTs (TH-D72A, or TH-D74A), looking to
> >>>>>>
> >>>>> make
> >>>
> >>>> QSOs by exchanging APRS messages with other stations. If you can work
> >>>>>> packet from your station, and we are in the same footprints, I hope
> to
> >>>>>> hear you (and see you on my screen) soon. Like W5PFG mentioned a
> year
> >>>>>>
> >>>>> ago,
> >>>>>
> >>>>>> let's get more stations on 145.825 MHz making QSOs...
> >>>>>>
> >>>>>> 73!
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> Patrick WD9EWK/VA7EWK
> >>>>>> http://www.wd9ewk.net/
> >>>>>> Twitter: @xxxxxx
> >>>>>> _______________________________________________
> >>>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum
> available
> >>>>>>
> >>>>> to
> >>>
> >>>> all interested persons worldwide without requiring membership.
> Opinions
> >>>>>> expressed are solely those of the author, and do not reflect the
> >>>>>>
> >>>>> official
> >>>
> >>>> views of AMSAT-NA.
> >>>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
> >>>>>>
> >>>>> program!
> >>>>>
> >>>>>> Subscription settings: http://www.amsat.org/mailman/
> listinfo/amsat-bb
> >>>>>> _______________________________________________
> >>>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum
> available
> >>>>>> to all interested persons worldwide without requiring membership.
> >>>>>>
> >>>>> Opinions expressed
> >>>>>
> >>>>>> are solely those of the author, and do not reflect the official
> views
> >>>>>>
> >>>>> of
> >>>
> >>>> AMSAT-NA.
> >>>>>
> >>>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
> >>>>>>
> >>>>> program!
> >>>>>
> >>>>>> Subscription settings: http://www.amsat.org/mailman/
> listinfo/amsat-bb
> >>>>>>
> >>>>> _______________________________________________
> >>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum
> available
> >>>>> to all interested persons worldwide without requiring membership.
> >>>>>
> >>>> Opinions
> >>>
> >>>> expressed
> >>>>> are solely those of the author, and do not reflect the official views
> >>>>> of
> >>>>> AMSAT-NA.
> >>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
> >>>>>
> >>>> program!
> >>>
> >>>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> >>>>>
> >>>>> _______________________________________________
> >>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> >>>> to all interested persons worldwide without requiring membership.
> >>>>
> >>> Opinions expressed
> >>>
> >>>> are solely those of the author, and do not reflect the official views
> of
> >>>>
> >>> AMSAT-NA.
> >>>
> >>>> Not an AMSAT-NA member? Join now to support the amateur satellite
> >>>>
> >>> program!
> >>>
> >>>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> >>>>
> >>> _______________________________________________
> >> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> >> to all interested persons worldwide without requiring membership.
> >> Opinions expressed
> >> are solely those of the author, and do not reflect the official views of
> >> AMSAT-NA.
> >> Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> >> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> >>
> >>
> >
> > --
> > 73
> > -------------------------------------
> > Jim Walls - K6CCC
> > jim@xxxxx.xxx
> > Ofc: 818-548-4804
> > http://members.dslextreme.com/users/k6ccc/
> > AMSAT Member 32537 - WSWSS Member 395
> >
> >
> >
> > _______________________________________________
> > Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> > to all interested persons worldwide without requiring membership.
> Opinions
> > expressed
> > are solely those of the author, and do not reflect the official views of
> > AMSAT-NA.
> > Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> >
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 5
Date: Sun, 16 Apr 2017 19:18:56 -0500
From: John Becker <w0jab@xxxxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Thoughts on ISS packet switch back to 145.825
MHz (long)
Message-ID: <28426faf-5cce-16b5-2763-4698c7ee83ff@xxxxxxxxx.xxx>
Content-Type: text/plain; charset=utf-8; format=flowed
just turn the thing off. end of all problems.
------------------------------
Message: 6
Date: Sun, 16 Apr 2017 19:42:01 -0500
From: Gabriel Zeifman <gabrielzeifman@xxxxx.xxx>
To: AMSAT Mailing List <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] Thoughts on ISS packet switch back to 145.825
MHz (long)
Message-ID:
<CAEGYLCs71=KNDQ0Z623je2tqk+CROYY91yha1RwB4EL+dwX+7g@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
I think this video should clear up everything:
https://www.youtube.com/watch?v=h73EYcyszf8&t=957s
If everyone calls at once (unattended beacons, ops, whatever), it jams it
up, listen to that mess when everyone is calling at once. Simple as that!
It's not complicated. However much it may be insisted ISS packet is not
SO-50, it is practically the same thing (single channel operating on FM).
73,
Gabe
NJ7H
On Sun, Apr 16, 2017 at 7:18 PM, John Becker <w0jab@xxxxxxxxx.xxx> wrote:
> just turn the thing off. end of all problems.
>
>
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Subject: Digest Footer
_______________________________________________
Sent via amsat-bb@xxxxx.xxx.
AMSAT-NA makes this open forum available to all interested persons worldwide
without requiring membership. Opinions expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT member? Join now to support the amateur satellite program!
http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
End of AMSAT-BB Digest, Vol 12, Issue 103
*****************************************
Read previous mail | Read next mail
| |
