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FT7900 + DW on RPi

 

Good afternoon (at least here),

I am considering attaching a Yaesu FT-7900 to a RPi for use with DW as a Digi... I've got it (mostly) working (I think) on a FT897D, but I'd rather not tie up the multi band, multi mode rig if I can help it (I am sure you all understand).

My questions;
1, Is there any reason why this might not work?
2, Does anyone have any experience of doing the same, and if so any pointers?
3, Would I need any specific cables (do I need to hook in to the mic and speaker or can I use the port on the rear)?

Kind regards from a rather sunny southern England.

73,

Neil -?2E0LNX
 

>> My questions;
>> 1, Is there any reason why this might not work?
? ? ? ?? The FT7900 would work just fine, especially since it has the 6-pin miniDIN Data jack.? That is the ideal connection for your packet interface .

>> 2, Does anyone have any experience of doing the same, and if so any pointers?
???????? I don't have a FT7900, but hyave worked with the FT7100 and FT8800 (previous, similar models).
???????? You don't say what interface you are using, but these radios do NOT have a CAT PTT command and VOX is not a good idea.
???????? You best bet is to use the Pi GPIO for hardware PTT.

???????? I am a BIG fan of the Nexus DR-X (crosspatch) board for interfacing between the Pi, sound card, and radio.
??????????????
? ? ? ?? Even if you use a normal USB sound card and only 1 channel of the DR-X, it has some nice advantages.
?? ? ? ? If you decide to buy the Fe-Pi sound card, you can get 2 channels for 2 separate radio interfaces.

>> 3, Would I need any specific cables (do I need to hook in to the mic and speaker or can I use the port on the rear)?
????????? With the Nexus DR-X board you only need a 6-pin miniDIN cable from board to radio.??
????????? Maybe 2 short stereo cables from sound card to DR-X board.

????????? With aother interface, make sure you have the hardware PTT (either COMM port RTS, DTR, or Pi GPIO).??
????????? Most, like the DIGIRIG (I believe), have some sort of configuration jumpers for PTT.??
????????? Just make sure they are hardware pins and NOT CAT.

If you provide more information on the interface, we can provide more details on the cabling.

Robert Giuliano
KB8RCO



On Sunday, April 7, 2024 at 11:04:13 AM EDT, Neil Stone - 2E0LNX <neil.stone@...> wrote:


Good afternoon (at least here),

I am considering attaching a Yaesu FT-7900 to a RPi for use with DW as a Digi... I've got it (mostly) working (I think) on a FT897D, but I'd rather not tie up the multi band, multi mode rig if I can help it (I am sure you all understand).

My questions;
1, Is there any reason why this might not work?
2, Does anyone have any experience of doing the same, and if so any pointers?
3, Would I need any specific cables (do I need to hook in to the mic and speaker or can I use the port on the rear)?

Kind regards from a rather sunny southern England.

73,

Neil -?2E0LNX

 

¿ªÔÆÌåÓý


Hello Neil,

1, Is there any reason why this might not work?

No.. it should work fine.? Both the FT897 and the FT7900 offer a rear 6pin DIN connection so that should make moving things over pretty easily.? I would recommend to re-verify the RX and TX audio levels though.


3, Would I need any specific cables (do I need to hook in to the mic and speaker or can I use the port on the rear)?

Using the rear 6pin DIN connection is the recommended approach for both 1200bps AFSK packet radio and especially 9600bps FSK packet radio.

--David
KI6ZHD
 

You might find the direwolf Radio Interface Guide helpful.



73,
John WB2OSZ
 

Hi Neil,

We are using Yaesu FT-7900 radios for Packet Communication within our local ARES/RACES group and those radios are a good choice for that purpose.

As others have already mentioned, do use the 6-Pin data connector at the back of the radio. The one pitfall that exists with the 6-pin mini-DIN connector is that it offers two audio output signals (pins 4 and 5). Audio output on the data connector depends on the Menu Setting #26 (PKT.SPD = Packet Speed) which depending on your radio interface cable needs to be set to 1200 (receiver audio on pin 5) or 9600 (discriminator audio on pin 4).

Important: the Packet Speed setting controls the audio output for the data port. It is irrelevant what the actual data rate is that you are using. However high-speed data (9600 baud packet, VARA-FM wide) generally requires bypassing deemphasis and therefore the need to use pin 4. For 1200 baud packet or VARA-FM narrow either audio pin will work.
Again (since this is a common mistake), the menu setting controls the audio output on the data connector and needs to match the way your cable is wired. The radio does not care about the baud rate of your signal.

You may also want to set menu #25 (PKT.MIC = Packet Microphone) to disable the microphone for a radio dedicated to packet use.

You do need to use a proper hardware PTT signal. This can be a GPIO pin from the Raspberry Pi but see the DIrewolf User's Guide for a number of other ways to produce a good PTT signal. There are DRA models (from Masters Communications) that have mini-DIN6 connectors which means you only need a straight-through cable to connect the radio to any computer with USB port. The DRA uses a GPIO pin on the audio interface to produce PTT for the radio,
This makes the Direwolf configuration easy as well (just "PTT CM108" will do in that case).

73,
Thomas
KK6FPP
 

Thank you all very much for guiding me toward the rear ports, I think I am well equipped?to head in to the realms of making/purchasing a cable for this.

KK6FPP - I am using this as part of a home config for Raynet... the UK version of ARES.

I just need to get my head around DIGI/iGate and filtering and I'll be away...

73,

Neil - 2E0LNX

On Sun, 7 Apr 2024 at 22:21, Thomas Leibold <leibold@...> wrote:
Hi Neil,

We are using Yaesu FT-7900 radios for Packet Communication within our local ARES/RACES group and those radios are a good choice for that purpose.

As others have already mentioned, do use the 6-Pin data connector at the back of the radio. The one pitfall that exists with the 6-pin mini-DIN connector is that it offers two audio output signals (pins 4 and 5). Audio output on the data connector depends on the Menu Setting #26 (PKT.SPD = Packet Speed) which depending on your radio interface cable needs to be set to 1200 (receiver audio on pin 5) or 9600 (discriminator audio on pin 4).

Important: the Packet Speed setting controls the audio output for the data port. It is irrelevant what the actual data rate is that you are using. However high-speed data (9600 baud packet, VARA-FM wide) generally requires bypassing deemphasis and therefore the need to use pin 4. For 1200 baud packet or VARA-FM narrow either audio pin will work.
Again (since this is a common mistake), the menu setting controls the audio output on the data connector and needs to match the way your cable is wired. The radio does not care about the baud rate of your signal.

You may also want to set menu #25 (PKT.MIC = Packet Microphone) to disable the microphone for a radio dedicated to packet use.

You do need to use a proper hardware PTT signal. This can be a GPIO pin from the Raspberry Pi but see the DIrewolf User's Guide? for a number of other ways to produce a good PTT signal. There are DRA models (from Masters Communications) that have mini-DIN6 connectors which means you only need a straight-through cable to connect the radio to any computer with USB port. The DRA uses a GPIO pin on the audio interface to produce PTT for the radio,
This makes the Direwolf configuration easy as well (just "PTT CM108" will do in that case).

73,
Thomas
KK6FPP

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