[NLRS] Thoughts on VHF-UHF beacon hardware.

[Doug Reed]

Using the Ras-Pi does open up remote access and control via the
Internet or a second radio path, like packet. I would practically
guarantee that if you search you will find that someone has already
written the code for sending a WSPR beacon packet or just about
anything else you want, including packet and APRS, on the Ras-Pi. For
that matter you will find similar code snippets for whichever is your
favorite hobby processor.

I used to like the PICs because we used them at work. Now I'm finding
the Arduino-based boards more interesting because they start at under
$5. This week I was reading a web page about building an Arduino-based
APRS digi station where the chip does all the RX decoding. That seemed
impressive for a sub-$20 board.

I picked up a "NodeMCU" ESP8266 board last week. It is about the size
of two postage stamps and its primarily designed as a WiFi interface.
But it also has on-board script-based programming capability and one
analog input plus 6(?) digital I/O pins. This particular board has the
regulators and level conversion to/from USB on the PCB for sub-$12. It
is designed and intended for "smart" sensors that talk over WiFi to
the Internet for data logging and control, part of the "Internet of
Things."

For projects needing more CPU, the various Ras-Pi boards are
interesting, I have a B+ and a B2 board. Lots of capability but they
are almost "expensive" compared to those Arduino boards.... And I've
been playing with a $55 TW700 7" tablet running Win 8.1. It can run
many of the standard sound-card programs written for Windows, which
makes it another possibility for a portable station, propagation
monitoring, or as a beacon controller. A couple friends have played
with the Beagle Bone Black but neither really liked it.

But the U3S kit is intended as a low-power HF/VLF beacon and with the
new SI5351A oscillator module it can directly generate RF up to 2M. I
think it is fairly cost effective and is dedicated for the purpose. It
is low power, even with the GPS, and can be built into a solar powered
HF beacon station if you want. $30 for the U3S, plus $6 to upgrade to
the OCXO SI5351A oscillator, and $21 for a GPS module kit. I've got an
old 6M Mocom to use as a 15W power amp. It could do a 1 minute PI4
beacon at 50.278MHz, then follow with a 1 minute CW beacon at 50.06x
MHz, then maybe a 2 minute WSPR beacon at 50.278, and another 1 minute
CW beacon, then repeat forever.....

That is one idea, there are no end of options. I also thought of using
the U3S to step through multiple bands, 5 bands, 1 minute PI4 beacons
on each band? Want to get really creative, build 5 identical sets, put
them in 5 different states, and have them cycle through the 5 minute
band sequence in round-robin fashion, like the NCDXF/IARU HF beacons.
Listen to one frequency and in five minutes you would know about any
openings to the five locations.... A new project for NLRS? But only if
someone offer sites to host them?? Using PI4 mode also allows
automatic monitoring and reporting.....

73, Doug Reed, N0NAS.