[OZAPRS] How much power do you use while HF mobile?

[OE3MZC Mike]

I have been using HF-APRS on 10MHz (30m Band)  several months while 4WD
Western Australia and Namibia, Angola, Botswana...but also across Europe.
The result: mobile low power use does produce usable results ONLY if you are
in 1-hop distance to numerous hf-gates
AND only with ROBUST PACKET MODE !
As this is not the case in most instances, I would recommend 50Watt minimum
in FSK- 300Baud packet mode for mobile antenna operation.
In Europe we have several gates scattered all across Europe, but mainly in
Southern European countries, but we also suffer significantly higher man
made noise on hf. So weak signals are often corrupted and cannot be decoded
by hf-gate modem.

Noise levels in Africa are much more comparable to low noise levels in VK,
but HF-Gates are only located in ZS and V5.
Fortunately some of these gates support DUAL-MODE-RECEIVE for conventional
FSK 300 Baud and Robust Packet (RPR) at same time and within same if-filter
bandwidth.
So I could easily compare results and RPR is 90% more reliable for being
decoded.

My setup was:
YAESU FT100
PWR 60W
Antenne: 4m glass fibre whip
SGC automatic antenna tuner at bull bar or bumper
SCS DSP-TNC

So my opinion: 5W hf-APRS only works on sailing boat within single hop
distance to gate.
vy 73 de OE3MZC/VK3FPF


-----Original Message-----
From: ozaprs-bounces at aprs.net.au [mailto:ozaprs-bounces at aprs.net.au] On
Behalf Of Gordon VK4VP
Sent: Freitag, 10. Juni 2011 12:07
To: 'Australian APRS Users'
Subject: Re: [OZAPRS] How much power do you use while HF mobile?

Damien,
	I usually run about 70W mobile, but there are certainly locations
where it doesn't make much difference how much power you run, you have
trouble getting in.  The band conditions are what makes the difference I
think.



Regards,
Gordo VK4VP

-----Original Message-----
From: ozaprs-bounces at aprs.net.au [mailto:ozaprs-bounces at aprs.net.au] On
Behalf Of Damien Gardner Jnr
Sent: Friday, 10 June 2011 18:35
To: Australian APRS Users
Subject: [OZAPRS] How much power do you use while HF mobile?

Hi Folks,

So I dug out a spare welding rod, and made a new tip for the 30 metre whip
on the the car, so I could run HF as well as VHF while we're away this long
weekend.  Didn't last long, it disappeared somewhere through kangaroo
valley, but we did get excellent coverage all the way down till then :) Will
go hunting around nowra tomorrow and see if I can find a source of 3mm
welding rods, or (haha not a chance) 3mm stainless rod, but for now I picked
up a $4 fold-out mosquito net thingo from the camping section at kmart, for
putting over a plate..  That had about 1mm rods in it, cut it to the 152mm I
usually cut to, but it was centered about 300khz too far up the band..  cut
a new one 3cm longer, and bingo, 1.1 swr on 10.1mhz :)  Gotta say having the
LCD backlight set to go from blue to red on SWR during transmit is
absolutely fantastic - you know straight away if something's wrong!

Anyway, my question - While i was giving the car a test-drive with the
antenna on, on thursday morning, I had my HF SSID appear on my D710 - seems
it was picked up somewhere and gated around about and ended up out on VHF
via an igate...  What did surprise me, was I still had the 857 set to 5w,
from tuning in the antenna!  Now I usually run 50w on HF, but having done
lots of playing with PSK31 and the like recently, I'm realising that power
really doesn't make a whole lot of difference on HF, and having landed in
noosa on 5w, I'm wondering if I need to be running 50W..

Sooo - what power do folks usually run on HF APRS? :)

Cheers,

Damien

VK2TDG
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