[nos-bbs] Local Emergency communications but able to do e-mail if necessary
sv1uy at ham.depa.gr
Tue Feb 13 17:04:37 EST 2007
I have been following this thread with interest and I would like to tell you
my opinion on this matter.
First of all AGW can work with Airmail2000 provided you download 2 free
linking programs that allow you to connect AGW with Airmail2000. I have done
this last week and I can use Airmail2000 with my TH-D7 yes my TH-D7 (using
Maxframe 1 and PACLEN128) giving me the opportunity to download/upload e-
mail even with attachments on a 1200bps channel via my TELPAC NODE here in
Athens. I never had a single crash on my TH-D7 V2.0, early TH-D7s have a big
problem with KISS mode though.
You can use AGW even with a soundcard for 1200bps and some people have
claimed success with 9600 bps even depending on the radio they use (i.e. if
it is a fast switching data radio, 9600 really flies otherwise it is best to
stick to 1200 bps).
As for PACTOR and SCS well if you really want to get somewhere on HF you
need the speed and the only fast modem today is the SCS-PTC modems which
starts from 600 EUROS for PII or 772 EUROS if you want PIII but then again
PIII is not absolutely necessarry since PII is nearly as fast as a 1200 bps
packet radio TNC on VHF. And of course PACTOR can be used with Airmail2000
and JNOS and FBB and in terminal mode with PLUSTERM and with ET4 for file
transfer. So really all you need is an HF radio, an SCS-PTC controller and a
cheap laptop. This is only 600 EUROs dearer than an HF radio and a laptop
and a person that can afford 700 EURO for a cheap HF radio and 600 EURO for
the cheapest laptop today (I bought a new one for 500 EURO last week) can
easily afford the extra 600 for an SCS-PTC modem.
Of course there is PSKMAIL that supports ARQ but with PSK125 and an
effective speed of 100 bps it can hardly compete with PACTOR III at nearly
5000 bps in a good channel and with its robustness through QRM there is
nothing, even military modes, that can beat it for effectiveness and
performance. Really nothing even comes close to PACTOR III. Compare the
speed difference of the most expensive PACTOR to PSKMAIL is 50:1. If PSKMAIL
ever manages to support RFSM2400 (which is less than half the speed of
PACTOR III but not at all as robust as PACTOR III when QRM/QSB/Multipath
Distortion is present) then we might have some hope but then again RFSM2400
is not OPENSOURCE at all, which takes it again out of the game. But I
personally doubt this is ever going to happen since RFSM2400 works in
Windows and PSKMAIL works in LINUX.
If money is the problem then probably your best bet is to use VOICE ONLY
emergency comms. Nothing can beat VOICE for simplicity and cost
Also, noone is ever going to spend the extra money or time to setup
something for emergency if he/she does not get anything out of it. And this
something is at least the satisfaction of using a fairly fast system to
exchange at least a decent e-mail that he/she can rely on for everyday use
when there is no emergency. This way one will be trained on how to use such
a system and this will prove very useful in case of a real emergency since
the operator will be familiar with the system.
This is definately not something that can only do 100 bps.
As for saving 600-770 EUROS is what one is after then one should better
stick with VOICE communications which is a lot cheaper since you do not only
save on the SCS modem but on the laptop too so the saving is at least 1500
EUROS leaving you with the price of an HF/VHF radio only. One can easily
serve his/her local community this way.
Airmail2000, JNOS, FBB and many other systems are decentralised systems if
one wants to use them as decentralised systems but you must find the people
who are willing to leave their systems switched on 24/7 which is very
difficult to do.
Only Winlink2000 is not a decentralized system and relies on Internet
although the guys who support Winlink2000 will assure you for the opposite.
I use Winlink2000 when I am on holidays away from an Internet Cafe and WiFI
access and I like it very much because it is fast but I am not sure how good
it can be when Internet goes down, that is why I run two 24/7 JNOS systems
with HF/VHF/UHF ports here in Athens and not a Winlink2000 PMBO.
Finally I would like to say that it is not only hardware that makes a
network but the people who make the network. Sometimes politics get in the
way and people get sick of it, so no PACTOR MODEMS or Computer sound cards
can save us.
73 de Demetre Valaris - SV1UY
e-mail: sv1uy at ham.depa.gr
AX25 PBBS: SV1UY at SV1UY.ATH.GRC.EU
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