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Re: FT8 - HELP!!!


 

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Hi Rob,

You need to key the rig with the TRS jack, not the DIN.? The DIN heads over to the FM world, and I don't recall it working with the HF SSB modes, though I could be wrong.? My head was getting rather flat from the wall it was hitting about then trying (as you) to get the thing to work.? Again, the rig is trying to be smart, and either over- or under-doing it.? The "quaint" (now antiquated) model of the world was using separate, external TNCs for HF and VHF digital, so they have separate jacks in the back of the rig, and "logic" to try to figure out where the audio is coming from.

The PTT "signal" is an open-collector style pull-down through about a 2.2k resistor.? That goes to the Tip of the TRS plug along with the audio after a 0.1uf DC blocking capacitor.? The TRS "Ring" is the received audio that goes directly to the audio line-in of the computer.

Hope this helps,

Greg? KO6TH


Rob wrote:

Thanks Greg & Tom

I think I understand but I still cant get it to work.

I was only wanting to use the 847 on 2m FT8 and was wiring to the 6pin data socket only.

The soundcard USB Data mode cable I am using is a UD01UN. It connects to a soundcard and has 3 wires to attach.

Audio Out,?Microphone Input and PTT.

I wired them to the 6 pin din to pins 5, 3, and 1 (I must have the audio cables the right way as I can RX FT8)

I stopped using CAT for PTT and configured the PTT to use RTS on the com port the data cable mode.

When I start WSJT the frequency is read (by CAT) and it starts receiving......if I click on UTNE in wsjt the little red light comes on in the data cable but the rig doesn't go into Transmit :-(

I am now wondering whether there is a PTT signal coming out of the Data cable....... The data cable doesn't show any other connections to make... just the 3 (Audio Out,?Microphone Input and PTT.) no GND connection. Should I be able to see something happening on the PTT wire with my multimeter?

TIA

regards

Rob (getting fed up now!)



On Mon, Oct 11, 2021 at 06:42 PM, Greg D wrote:

What Tom said.?

The 847 is centered in the "uncanny valley of engineering" with its handling of PTT.? Too smart, and not smart enough.? It apparently tries to choose the audio source from wherever PTT is sourced, so if PTT comes from the TRS jack on the back (used for HF modes), audio from that source is used.? Same for the Packet connector.? The problem comes with using CAT.? There is no way to associate a particular audio source when the rig is keyed with PTT, so it uses the hand Mike input.? That is bonkers, because the Mike is the last place one would expect audio to come from when using a computer to key the rig.

So, the only way I was able to run FT-8 (et al) with the 847 is to key the rig from the TRS jack in the back, using a USB Serial dongle and its RTS / DSR pins driving a small level shifting circuit and DC-blocking capacitor.

For extra credit, try combining both HF and VHF digital modes (both connectors) to a single Raspberry-Pi based "TNC".? Can be done.? Not pretty.

Greg? KO6TH


K6EU wrote:
Not having?AF out connected to the tip would cause the problem you are seeing.? ?I have a FT-847 running FT8 using PTT multiplexed with AF out per the manual.??
?
73,
?
Tom K6EU
?
?

On Mon, Oct 11, 2021 at 9:38 AM Rob <g4ujs@...> wrote:

hi is anyone using the 847 for FT8.

I've connected sound card to data in/out

PTT is via CAT.

i can RX stations with both JTDX and WSJT.

When I hit tune the rig goes into TX but no power output..... its as if the audio isn't getting into the rig.

As i am using CAT for PTT I haven't wired PTT to the tip of the data connector....is this my problem?

HELP!

73 de Rob G4UJS

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