Datamode SOTA

I’m nipping out this afternoon to try a new configuration out for doing PSK on a SOTA activation. There’s a few new aspects to this, so there’s a few reasons it might fail. But no worries, if it does, I’ll happily play on CW and SSB (which I might do in addition to the PSK31 anyway!)

It’s rather short-noticed to hope for a PSK S2S, but you never know. But, chasers, you have about 1.5 hours to have your PSK systems up and running!


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Hi Tom
Sorry but I do not do psk, but well done for trying.
Cheers Ken

a good idea Tom!

Did you run outside the usual PSK freq?
I might do it some day

I only found this at 1700.

I would have listened for you, but band was mentioned.


Sorry, no band was mentioned.


Nobody missed anything. It didn’t work. I had picked up a cheap 2nd hand Arnova Android tablet and was hoping to use this to run DroidPSK app and connect to my FT-817 using the Wolphi-Link adapter and cables. Anyway, it couldn’t send or receive via the wired connection, so it’s probably too old. I had seen something that this set-up would only work on 2nd Generation and up tablets.

8 contacts were made on 20m CW, including 3 into the USA and a S2S with EA5FV/P on EA2/TE-003.

Anyway, the tablet-PSK woes were not the only ones on this disappointing activation. My radio-controlled clock seemed to freeze, and needed to be restarted. I did this, but this particular model seems to take an incredibly long time to latch onto the LF signal (I’m not sure whether this model is listening for the 60kHz signal from Anthorn or the 77.5kHz from Mainflingen). Anyway, it did find the correct time - but only well after the activation!

I also had problems with the speed calibration of my Palm Code Cube. Again. Even with the dial on the lowest possible setting, it was still motoring along at about 30wpm, which is rather too fast for my fingers, let alone the ears of the chasers. Well done to those of you I worked, and apologies for anyone that I was too fast for. Of course, back in the shack, the recalibration procedure worked perfectly first time! Three attempts to do that on the summit all failed.

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I’m confused Tom, the screen shows RX working, did TX not work?

Anyway, if the Palm cube problem only happens on a summit and not in the shack then it’s probably due to moisture ingress or temperature. Judging by how grubby that 817 is in the picture, there’s probably similar gunge in the cube which when in a damp atmosphere, is shorting out internal contacts in the cube.

Hi Tom,
Sorry to hear of the dissapointing outing - I’m guessing you meant to say it couldn’t …
I wonder if the issue is with the headset socket - the Wolphi-link takes its power from the phantom power that is in the microphone line of phones and tablets for electret mic. inserts. If your tablet only has audio out on the 3.5mm socket - i.e. it’s for headphones rather than a headset - which was the “norm” for tablets, there will be no microphone connection and hence no voltage to power the wolphi-link.

73 Ed

Yeah that could be it Ed. It’s a cheap 2nd hand tablet, no box or manual. It is G3 though, so I thought it would be modern enough to be compatible. I did wonder that myself, but the research I have done indicates that the Arnova 7h G3 tablet can be used with a headset mic. (Typo corrected BTW!)

Andy, yes the RX worked FB. I’ll keep the Mini Palm Paddle and Code Cube in the warmth and dry of the shack for a week or so, and out on the bench disconnected to get a good airing!

OK, if it’s 3G capable, I would expect a 4 pin 3.5mm socket to support a headset as it is then a fairly new tablet. Probably the tablet will only connect to a data 3G connection and not support voice, but with 3G connectivity, Skype is often assumed and therefore a headset socket rather than just a headphone socket is most likely.

Oh hang on you said G3 not 3G - are you referring to the model - in any case, take a look at this page to see if you can find out more about the tablet:

(not sure why it thinks I’m located in Fiji, but what the heck).


What I found out with a cheap Linx 7" tablet is that you have to load the MIC input (if there is one) with a resistor to make a DC path to ground. I used a 6k8 resistor.
With just a series capacitor, the internals didn’t switch over to this input and kept using the built-in mic.
73 Luc ON7DQ

PS I i just looked at the schematic of that WolphiLink here
I see they use the DC on phone/tablet pin 4 (= the MIC input) for the PTT transistor T1, but I don’t get how the received audio from DIN pin 5 is making it to phone/tablet pin 4 ???
It seems it’s coupled back to the phone OUTPUT. … intentional drawing error to avoid copying ?

Further research led me to this page:

…so it seems that there isn’t a “microphone in” on this tablet. So no good for my portable PSK set-up.

I’ll dig my multimeter out and measure the voltage across pins 3 and 4 from my HTC One Mini smartphone to get a definitive answer as to whether this will/should work. Previously when I had one of these phones, I couldn’t get it to work.

Failing that, I have one of these so-called “free upgrades” coming up on my mobile phone contract. As I am happy with my HTC phone, I’ll see if the “upgrade” can be to a less-than-optimum Samsung S-? (which I know will work with the datamode set-up) and not increase my monthly contract. Could be tricky, as in my experience, the whole idea behind these “free upgrades” is to get you to pay a few quid more per month than what you were paying…!

It should be possible to disconnect the internal electret microphone and add some wires to a switching socket to offer either internal mic or external mic. It’s not difficult TBH but if you don’t have experience of opening up consumer devices like this you may seriously fubar the case the 1st time you try.

Slightly OT and maybe this applies to the UK phone market more than anywhere else but I would quite strongly suggest that anyone on a contract that includes a phone rather than a SIM only deal is having their wallet reamed. My advise would be to switch to either a 12month SIM only deal or even the now popular 1 month rolling contract SIM only deals and buy your own phone as it is so much cheaper. There are some fantastic non-mainstream phones available now for very little money so buying iPhone 7s or Samsung Galaxy S7 etc. is merely for the bling value as the phones do not offer anything significant over the now excellent Shenzhen specials available. I work in the semiconductor industry supplying design support and IP to the major phone semiconductor companies. I know what will be in your phones in the next few years and knowing this I see no need to buy a £600 smartphone when the Shenzhen specials offer 98% of the features and performance for £150 max. (Thanks Tom for buying a phone that contains a fair bit of stuff I’ve worked on!)

Following on from Andy’s comments - I find even with pre-paid SIMs it’s better to buy one for a phone and put it in your tablet than buy the Tablet version. The “data only” SIM charges data at twice or three times the price (for the same volume/speed) compared to using a standard phone SIM. This seems to be common practice across networks.


On Friday, Tom assured me that he had a Degree in Impracticability. At least I think that was what he said.

He plays a musical instrument and use Morse. This means he has dexterity and timing skills. Like learning Morse and an instrument, he just needs to practice at practical stuff. :slight_smile:

Sounds like a plan. Keep my HTC phone, switch to a SIM-only deal and pick up a cheap 2nd hand Samsung Galaxy S? handset or tablet to do the PSK. I’m sure the then redundant Arnova tablet will find a use elsewhere in the EYP household…

Not sure how that would work - the data interface connects to the smartphone via a 4 pin 3.5mm jack. If the socket is 3-pin, then that’s a problem isn’t it?

That’s just a SMOW issue needing 2 plugs, one for the mic, one for the speaker connecting to a common 4 pin socket for the interface.

(SMOW: small matter of wiring.)

The world is full of excellent 2nd hand phones as people upgrade etc. You can use an old Android device that no longer gets security fixes and has been dumped for that issue for the datamodes software. You may not worry about it getting hacked because it’s not your real phone so you can just reset to factory settings. Worst issue is you may have to buy a new battery for it.

I have a Moto g 3rd gen phone and for under £150 after I put a micro SD card upgrade in it is an ideal phone for not much money. Then a sub £10 a month sim contract is all I need. I need to get a data mode connection to my phone from my new ft817 before I can play sota on PSK tho. Then save up to buy droidpsk lol