[OZAPRS] Considerations For Setting Up an igate (RasPi)

Mon Dec 16 20:49:49 AEDT 2019

Yeah, I think a WIDE1-1 might be good, but the transceiver board may not be
great at modulating audio.

I might see if I can get a ladder onto the roof and mount it next to the TV
antenna mast. That would also resolve the power issue as well, but at this
stage I think roof access is unlikely. It's also a very old house, so there
are safety issues as well.

Raspberry Pi Zero W power consumption is a little over 0.5W (running
direwolf may raise this slightly), the dorji board is about 0.2W on RX &
2.5W at 1W RF TX and that's about it. This is from datasheets and people
who have measured these online. So all up, average should about 1W or
24Wh/day, or 2W max or 48Wh/day. 12A 12V is about 144Wh, let's say 72 hours
to be conservative, and fixed 18W solar and minimum 9.75 hours of sunlight
in winter should get in the region of 50Wh/day. In really bad weather for a
few weeks, brownouts or blackouts are possible and without proper circuitry
to manage power state, the pi could go into an unknown state. To partially
tackle that, I would consider only having the SD card in read-only mode.

And install, I would have to install it about the 2nd / 3rd Jan if I was
going to do it, I'm moving to VK4 and it'll be on my trip up to there.

73,
vk3tst / vk5wtf

On Mon, 16 Dec 2019 at 06:30, Warren_Brown <warbn at telstra.com> wrote:

> Hi Marcus,
>
> Yes I would have it transmit to VHF, you never know where it may get heard.
>
> I would consider a Wide1-1 Digi also, just to provide local feedback to
> anyone travelling through.
>
>
>
> As for antennas, any sort of gain would be good, whilst no real height
> gain a roof top mount may be more study than a telescopic mast that you’re
> only going to visit once in a blue moon.
>
>
>
> As for 12v power, the real killer will be the standby current, how much
> does the gear use when Idle?
>
>
>
> How long before you plan to install it?
>
>
>
> Another option would be a satellite APRS Gateway
>
>
>
> 73,
>
> Warren vk3byd
>
>
>
> *From:* OZAPRS [mailto:ozaprs-bounces at aprs.net.au] *On Behalf Of *Jack
> Schultz
> *Sent:* Monday, 16 December 2019 09:26
> *To:* Australian APRS Users
> *Subject:* Re: [OZAPRS] Considerations For Setting Up an igate (RasPi)
>
>
>
> I won't comment on the hardware/operating environment considerations - but
> my 2c is TX capability is much preferred - especially given its location
> away from existing network coverage. The secondary benefit is another tropo
> indicator.
>
>
>
> Another thing I will note is that VK3RMK-1 is not the most reliable
> indicator of traffic - at a guess it is down most of the time. VK3RCU-1 may
> be a better indicator but most of your traffic will be Murray Valley
> Highway, so no source of data that picks up those who might travel out to
> Cohuna. I drive to Kyabram (from Geelong) quite regularly and lose reliable
> digipeater coverage around Nagambie, so if I travelled up to Swan Hill from
> there (for example) I wouldn't get a single ping out under normal
> conditions. So there may be more traffic passing through than you might
> guess. Similarly VK3REG-1 in East Gippsland has significant downtime, so
> misses a lot of the would-be traffic through the area.
>
>
>
> On Sun, Dec 15, 2019 at 11:58 PM Marcus B <mrmabs at gmail.com> wrote:
>
> Hey all,
>
>
>
> I had a thought bubble, probably unlikely to have time to pull this off,
> but you never know. So right now we'll treat this as an intellectual
> exercise, with a chance it might actually happen.
>
>
>
> A couple of months ago travelling through northern Victoria I noticed a
> lack of coverage (between Robinvale & Shepparton), and thought about
> setting up a small igate at a relative's place in Cohuna. If I did this I
> would be doing it just after the new year, and I won't be able to visit to
> maintain it potentially for 10 to 24 months. It's also unlikely that I
> would go to the trouble to open a remote port to ssh in, so must be
> reliable hardware and software wise. I have access to WiFi.
>
>
>
> What I have today: Pi Zero W with a protoboard to connect TTL serial to a
> dorji board + LDO regulator, and a usb sound card. Also have 4.5m Jaycar
> telescopic mast and I could put a DIY 1/4 wave on top. Also, the further
> away from the house, the better, so that means, if possible, run off its
> own power. Maybe a 12V 12A SLA & 10W or 18W solar panel will do the job?
>
>
>
> I have not done much TX testing, RX seems to work fine.
>
>
>
> It's pretty flat out there, so at 4.5m above ground, I may expect about
> 5-10km coverage (running on HeyWhatsThat.com confirms that it would be a
> very patchy to the west, and then there's the trees, and house roofs), and
> unlikely to hear anything on 145.175 unless some serious tropo comes in. I
> can also look up how to get up an igate with direwolf easy enough. In
> reality I might be lucky to hear one station a month given the reports I
> have seen for VK3RMK-1.
>
>
>
> How should I set this up, purely as an RX only igate? I have also
> considered just getting it to TX occasionally (30mins?) just to say hello,
> but at 1W eh... At this location in about 1996 I was able to have a
> scratchy QSO on VK3RMM on 5W (HT) using a CFA 160MHz 1/4 wave at 10m; so
> it's not all doom and gloom. That 10m was a solid steel pipe and it is
> looooong gone.
>
>
>
> With all that, what could I do to make this set up better? Best bang for
> buck? (Obviously the dorji modules are pretty low quality.) Location is
> pretty much fixed. What about to improve reliability? Best ways to protect
> from heat (does it need it)? What sort of protection (power, temperature,
> etc...) should I consider?
>
>
>
> What else am I not thinking about?
>
>
>
> Maybe, alternatively, I could make a 2m WSPR beacon on a Pi with filter
> and attach a GPS :P
>
>
> 73,
>
> vk3tst / vk5wtf
>
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>
>
>
> --
>
> VK3FJTS
>
> Jack Schultz
> _______________________________________________
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>

-- 
"The universe is an intelligence test." -- Timothy Leary
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