(tr)uSDX Forum

I developed an FT8 app for my iPhone, connected it to my new (tr)uSDX via an audio cable adapter, enabled VOX, set the Noise Gate to 50, and set the audio volume to 9 :
The iOS app is decoding and transmitting FT8.

Both the iPhone 12 mini and the (tr)uSDX weight less than 140 grams. So this combination should be good for minimum carry weight digital HF ops (SOTA).

My app can decode and encode both the standard message and free text. Approximately level 1 decoding only. If you have a recent iPhone or iPad, my ft8d app can be distributed to the iOS device for beta testing via Apple's TestFlight program. If interested, please email me directly for a TestFlight invitation.

73, Ron, N6YWU
http://www.nicholson.com/rhn/

Very cool Ron!

73,

Robert, WA2T

wa2t wrote: ↑24 May 2022, 19:02 Very cool Ron!

73,

Robert, WA2T

I double that ! Chapeau !

73 Manuel; DL2MAN

To bad I don't use iPhone, but could it run on iPhone emulator?

There seem to be other developers already working on FT8 apps for Android mobile devices, and for the Teensy 3.x uC. And you can run full featured WSJT-X on a Raspberry Pi, or small laptop (Window or Linux). I'm just working on providing some FT8 capability for that leftover device, the iPhone.

73, Ron, N6YWU

Very nice indeed!

I'm also trying to get FT8 working, with a laptop. I'm having the problem that connecting a stock cable to the Mic/Key port will enable TX permanently. Do you use a modified cable, or is there a way to disable keying on the mic/key interface?

(edited to correct an error)
To prevent Tx from being enabled in VOX mode, you may have to modify an audio cable so that PTT isn't asserted on the tip of the TRS jack (normally the stereo left channel). I got lucky, and one of the USB sound cards in my collection did that already.

I also had to adjust the Noise Gate setting so that the base audio noise level wouldn't trigger VOX.

If you use a direct audio cable from an iPhone or other iOS device instead of a USB soundcard, note that iOS devices usually require a specific impedance on the microphone input, said to be around 1.6kOhms, in order for the iPhone to enable any audio through the audio jack.

73, Ron, N6YWU

Ah, thanks for your answer!

According to the documentation though, it's the tip of the TRS jack that is PTT? Which would be the left audio channel?

My error.
Thanks for posting a correction.
The tip of the TRS mic jack is PTT. It needs to not be asserted by the audio cable or USB sound card.
73, Ron, N6YWY

How do I get the FT8 app?
Philip G7JUR

Has anyone gotten this to work other than the OP?

Seems like a Great Setup!

Hello OMs,

there is also a very new App for Android doing TX and RX without additional Hardware:
Google Play: FT8 Radio

https://www.youtube.com/watch?v=k3aimVTIOEM

only OTG to TX and Audio via standard Headphone connector....

73 de Chris DL6SEZ

Hi.
Can I carry out a full QSO with this app.
Philip.

The current iOS FT8 app includes no auto sequencing. But it does seem to be capable of decoding and encoding the FT8 messages (with 5 character or shorter call signs) in typical auto-sequenced FT8 QSO exchanges. It can also encode and decode free text (13 character limit). The operator has to decide what messages to transmit, type them in, and hit send (or play encoded audio) for the next selected even or odd interval, for each transmission.

So it should be possible to carry out a complete FT8 QSO with a patient operator on the other end.

73, Ron, N6YWU

Apple has approved my iPhone FT8 Decoder app for distribution from their App store:

https://apps.apple.com/us/app/ft8-decoder/id1592847401

It's not yet available in all countries. Let me know if it's invisible in your locale.
It seems to work for both receive/decode and transmit with my (tr)uSDX.
Several people have also successfully used the app to send FT8 signals for SOTA spotting.
Thanks to all those who helped beta test my app and provided me with feedback.

Other options:
For those of you with Android devices, a google search turned up these 2 options:
https://play.google.com/store/apps/deta ... n_US&gl=US
https://play.google.com/store/apps/deta ... n_US&gl=US
I don't have an Android mobile, so I haven't tried either of these.
In the ucx@groups.io, there also seem to be ongoing projects using the Teensy 3.6 and 4.1 for FT8.

73, Ron, N6YWU

N6YWU wrote: ↑03 Jun 2022, 02:26 My error.
Thanks for posting a correction.
The tip of the TRS mic jack is PTT. It needs to not be asserted by the audio cable or USB sound card.
73, Ron, N6YWY

Indeed, either using my sound cards or directly feeding the audio out to the computer into the PTT/mic jack sets the (tr)uSDX to TX as described. I am using a ready made "AUX" 2.5-mm stereo jack to 2.5-mm stereo jack cable. Will it work if I make a small cut in the coat and cut the tip-to-tip wire?
Thanks!
Mikel EA5IYL

Rather than cutting into the audio cable (where one could cut too little, or too much and create a weak cable), I found it easier to get a pair of male and female TRS jacks and solder two very short wires between just the ring and sleeve, leaving the tip disconnected. Optionally, you can add a resistor divider to adjust the audio volume a bit lower. Another option might be to create a Y and add yet another jack wired between tip and ground, so one can switch between digital modes and CW keying without having to unplug and plug things.
73, Ron, n6ywu

Thank you for building this! I bought it, although I did not have trusdx (yet)
But I used it for receiving with my xhdata radio and that works great !
I hope you will continue to update and expand it !