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20m FT8 DX S2S event / attempt ?


#21

Here you go:

http://k3s.wikidot.com/ft8sota

ultralight (262g) 8-inch Windows tablet, Nuvision M800W610L - I eventually discovered that I didn’t need a GPS device or an external soundcard, so it’s an elegantly simple and lightweight solution - but the main problem I have with a 32GB Win10 tablet is that it’s impossible to disable Windows update and the update keeps failing due to insufficient disk space to accommodate the stupid update process so it’s a real pita - don’t ask me, I’ve tried every single update disabling trick out there on the internet and none of them did the trick. That’s why I eventually just put it away.

73 Barry N1EU


#22

Windows 10 tablet running WSJT-X.

ZLP MiniProSC interface.

FT-817.


#23

That has just reminded me…

I’m sure that I saw somewhere cases with a touch screen to put a Raspberry Pi inside (effectively build your own Raspberry Pi tablet). I can’t remember where I saw it though…probably eBay.

I’m not sure how rugged they would be though. Might be worth a look?


#24

That’s pretty much what I thought people would be using.

Best bet is probably a really cheap second hand tablet which I don’t mind destroying.

Good point about the Raspberry Pi though Ed. I’m sure somebody somewhere must have already done something with one of them.


#25

For my understanding, SOTA activators have to post alert and specify summit reference, FT8 mode, band and approximate time. I believe that it will be sufficient for chasers to make SOTA contacts, using FT8.


#26

There is a version of WSJT for the Pi, not sure which Pi but I’d buy a Pi3B+ for this as it has lots of CPU horsepower and RAM. For the display, use the Pi’s own built in Wifi and run a VNC server on the Pi with a VNC client on your phone via the Wifi.


#27

SOTA activators do not have to post alerts - that is a courtesy to chasers so that they know roghly when the activator expects to be set up on the summit.

Ed.


#28

Having searched Amazon and eBay for a “complete Pi package” - It seems a self assembly package (put the parts in a supplied pre-cut box) costs at least €80 plus for a display at least another €40-70 (depending upon size) - to house the display a different box is then needed adding more cost up to €50.

For what I expected to be a cheap computer, it seems the Rasrberry Pi board itself is “reasonable” at about €30 but with all the other pieces needed the solution (still needing some assembly work) comes to a price close to a fully built cheap Windows 7" tablet!

Even leaving the display out and using a smartphone instead the price is higher than I had expected. Having tried to use a smartphone to run PSK31 from a SOTA summit, the readability of that solution doesn’t appeal to me albeit smartphones now can have larger displays that when I last tried it 5 years ago.

It seems a Windows tablet remains the most practical solution to run FT8 from a summit.

73 Ed.

P.S. Just found this video on the DRAWS Raspberry Pi hat - it’s certainly not going to reduce the overall price of a raspberry Pi based solution - rather the contrary but if what the video “supposes” about the product is correct, it will simplify alot of the ancillary equipment that is needed.


#29

£45 should cover it buying new and assuming you have an SDcard to use.

Pi3A+, USB audio, 6-18V PSU, case.


#30

Yes around 50 Euros was what I was expecting Andy, but i can’t see that through eBay even ordering from China. It seems the prices have gone up from what we both expect. have you got a link for components to make the unit up for £45 - £55 please?

73 Ed.


#31

Having just looked, there’s plenty of kits available on eBay for around £15 (add the cost of the Pi itself to that).

They are only 3.5" screen. I’m not sure if that’s a positive because it’s small & portable, or whether it would be a curse because it would be too small and awkward to run FT8 from?

Definitely not waterproof and probably not very durable.

They also seem to come from China. My experiences of buying cheap stuff from China haven’t been great!!!


#32

pimoroni.com

Pi3A+ £23.50
Case £6.50
USB audio £5.00
Wide input power kit £10.00

Prices include VAT but no shipping and I’m assuming you have an SDcard (4GB should be OK ISTR).


#33

I just got a refurbished 8" Windows 10 tablet from an online retailer for £60. I added a screen protector and padded case from my local PC World, and I have a robust, reliable and easy-to-use set-up for a decent price.


#34

Thanks Andy, that comes to amost exactly €50 plus UKL 5.50 shipping.

Correct I have several SD cards that are suitable, I also have several USB audio dongles. That wide-input shim users an TPS630701 buck-boost converter chip ( invertor ) which can (and normally does) create QRM on HF, so I’ll avoid that and simply supply the correct voltage directly.
This takes the cost down even further as I’ll just order the Pi, it’s case and add shipping and I’m something like €40 incl. shipping.

I wonder if there’s a pre-built Raspian/FT8 image already built which I can download?

Thanks again Andy - this is the sort of price I was hoping for.

73 Ed.


#35

I use the older version of this on my Iridium satellite SOTA spotter. I included the Pimoroni item as an example so thanks for the heads up that it is very RF noisy.

Mine is a 3A version that provides 5V to power a Pi B+ (2nd version of original Pi) from a 3cell LiPo pack. I can sit with the PiB+ and the PSU underneath my HF antennas and there is no QRM I can hear on HF from the PSU or computer.


#36

If you figure out how to disable Windows 10 update, please let me know (seriously).

73 Barry N1EU


#37

Actually I have a small LIPO LCD voltage monitor which connects to the charging lead so that I monitor battery cell voltages during operation and it has a built in USB power output port - so I have the required voltage already available - I believe its rated at 2 amps, but I’ll need to check.

Lets see how long the hardware will take to arrive - it could be a while at this time of year.

Thanks again Andy.

I’m sure I have read of a Raspian image that is specifically aimed at Amateur radio - if I can find that it should be a good fit.

Looks like I have my Christmas project - not that I needed another project!

73 Ed.


#38

Hi Andy,

Sorry i’m slow getting back but I work shifts and just come off nights. I haven’t got a clue about polls. Just thought it would be nice to see who else dabbles in FT8.

73’ Don GW0PLP


#39

Hi Andy,

Just a word of caution, A cheap tablet will probably be too slow for WSJTX V2.0.

Remember the program grabs the spectrum, extracts signals and decodes them, subtracts those signals from the spectrum and runs a second decode. This enables signals to have overlap and yet be decoded. The decoding includes error correction and a sort of common sense verification, rejecting most false decodes. Not one or two signals but over 40 commonly. All in a couple of seconds. A lot more grunt required than a $20 tablet will give IMO.

Re W10 updates, does the tablet get agitated if the internet connection is disabled?

73
Ron
VK3AFW


#40

I haven’t tried v2 but 1.8x ran happily on a W8 tablet and a W10 tablet