[VHFcontesting] Portable FT8 Was: FT8?- tarnation!

[Detrick Merz]

Zack,

I suspect most rovers are going to have so much power available that
current consumption isn't a concern. At least not enough of a concern to
drive using a Pi instead of a laptop. One of the main reasons I have
integrated a Pi into my rover setup is because it is so compact. It sits
out of sight, being a little workhorse in the background. Great for
offloading some mundane tasks onto.

As a rover in the Limited class, the Pi is handling APRS (Direwolf+FT1802),
runs my logging software (RoverLog), and acts as a WiFi access point. I use
a small, very cheap tablet as the display (across WiFi, using VNC), a small
bluetooth keyboard (seems to run forever on a charge), and a wireless mouse
(non-bluetooth, has its own USB dongle). An old cellphone running APRSdriod
connects to Direwolf over WiFi. While run&gun, I used a macbook pro for
WSJT-X because the truck has AC power available while the engine is
running. I don't let the truck idle for power while stopped because it's
not good for it, and because I have a small generator. The EU2000i provides
plenty of power for all of my equipment, largely because the RL class
limits my power output to a couple hundred watts. I use a couple LiFePO4
packs while transitioning from vehicle power to generator power, mainly so
the Pi doesn't have to be rebooted. Those LiFePO4 packs can also power all
of my radio gear when I can't or don't want to run the generator, it's
amazing how long they go for even when transmitting. Again, I'm
class-limited to 100-200w, which makes small LiFePO4 packs somewhat
feasible. They also get recharged while driving from one location to the
next.

I have used that same Pi 3 for WWFF/POTA, using the same LiFePO4 packs to
power the Pi, KX3, and (sometimes) KXPA100. I have also run the Pi off of
one of those cell phone boost packs, but it's right on the verge of the max
current consumption the cell phone boost pack can support. I keep one
SDcard with the Rover build, and another with the POTA build. This POTA
instance does away with APRS and Roverlog, retains the Access Point
functionality, GPSr+NTP, keyboard, mouse, and VNC tablet display, and adds
in WSJT-X. I have found it to be barely usable for FT8, there is simply too
much lag somewhere in the system. I haven't spent the time to figure out
whether the problem is due to slow decoding or display update lag (when I
said this is a cheap tablet, I mean it...I strongly suspect a better tablet
would solve this problem).

For future rover operations leveraging digital modes, I plan to use an old
HP laptop running linux (the macbook has mostly died). I have a couple of
old, but still decent laptops, so this is a less expensive path forward
than buying a new tablet. The generator also makes this easy to do, and I
know the laptop has plenty of processing power and screen real estate for
supporting WSJT-X. The Pi will remain in the mix to support those mundane
tasks. I even have some ideas for additional jobs for the Pi, but WSJT-X
isn't likely to be one of them...the laptop just makes it too easy.

HTH,

-detrick
K4IZ

On Thu, Jan 21, 2021 at 11:00 AM <alex at kr1st.com> wrote:

> Hi Zack,
>
> I'd be interested in those suggestions as well because I'm on a similar
> quest, but for a IC-705. So far it seems to me that something like a
> surface type tablet is the best option. It will run all day on it's own
> battery, but that may not be sufficient for your needs. I'm thinking in
> terms of SOTA or POTA operations. There are the GPD micro computers, but
> they don't come with a 10" display, which is what I'd prefer.
>
> 73,
> --Alex KR1ST
>
> On 2021-01-21 09:56, Zack Widup wrote:
> >
> > But I'm interested in using FT4/8 if needed in one of these contests.
> > Especially since I am very happy with the performance of my recently
> > acquired FT897D. I could easily make a connector for it. So I have a
> > question. Are any other Rover/Portable stations using some sort of
> > computer
> > that is small (like a Raspberry Pi) and doesn't draw a lot of current?
> > I
> > would really be interested in putting something like that together. I'd
> > like some recommendations.
> >
> > 73, Zack W9SZ
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