Topics

TNCPi WITH YAESU FT 7900R


Al Massaro
 

OK I am thinking of trying a TNCPi with a ft 7900r, the pigate site shows the pinout for a FT 2800/2900 using the mic port. My question is my 7900 has a rear data port why can't I use it? Her is a comparison of the 28/2900 mic pinout and my plan for my 7900. Do I need to figure out and use the pinout for the 7900 (MH48A6J) MIC PORT instead? Below left mic pinout from website, Below right my plan for 7900.


Jim Lange
 

You need to use the 1200 port on the radio. The other is for high speed packet and won’t work with a TNC that isn’t made for it. Otherwise all is good. 

Sent by me


On Jun 23, 2020, at 13:13, Al Massaro <almassaro1@...> wrote:

OK I am thinking of trying a TNCPi with a ft 7900r, the pigate site shows the pinout for a FT 2800/2900 using the mic port. My question is my 7900 has a rear data port why can't I use it? Her is a comparison of the 28/2900 mic pinout and my plan for my 7900. Do I need to figure out and use the pinout for the 7900 (MH48A6J) MIC PORT instead? Below left mic pinout from website, Below right my plan for 7900.
<dummyfile.0.part>
<dummyfile.1.part>


Al Massaro
 

Dummy me I knew that, guess I was thinking I had a TNC-Pi9K6.
Thanks 
AL M 
KF5SMH


Ed Bloom, KD9FRQ
 

I bought my cable from Hammadeparts.com (and ebay).

Works fine. I have not used it in a while as I created the setup for Emergencies
then packed it nicely ready to go out the door.

Ed Bloom, KD9FRQ
ewbloom@...
Sent from Webmail access


-----Original Message-----
From: Al Massaro <almassaro1@...>
To: RaspberryPi-4-HamRadio@groups.io
Sent: Tue, Jun 23, 2020 12:13 pm
Subject: [RaspberryPi-4-HamRadio] TNCPi WITH YAESU FT 7900R

OK I am thinking of trying a TNCPi with a ft 7900r, the pigate site shows the pinout for a FT 2800/2900 using the mic port. My question is my 7900 has a rear data port why can't I use it? Her is a comparison of the 28/2900 mic pinout and my plan for my 7900. Do I need to figure out and use the pinout for the 7900 (MH48A6J) MIC PORT instead? Below left mic pinout from website, Below right my plan for 7900.


Al Massaro
 

Thanks Ed, now to figure out if it is the Kantronics or 9800 style they have listed, nothing specific stated for 7900.
AL M
KF5SMH


Ed Bloom, KD9FRQ
 

Al,

Get the 6 Pin Min Din 1200 Baud to DB9 Kantronic Type cable from HamMadeParts.

Ed, KD9FRQ

On 6/23/2020 1:01 PM, Al Massaro wrote:
Thanks Ed, now to figure out if it is the Kantronics or 9800 style they have listed, nothing specific stated for 7900.
AL M
KF5SMH



Al Massaro
 

Ed, ok good to go, I just got back to this to work on the pinout for them and found your post, it is now on order.
Thanks
AL M
KF5SMh


Ray Wells
 

That's not quite correct. For receive, the difference between the 1200 and 9600 ports on the rear socket is that the former has de-emphasised audio while the latter has "flat" audio from the discriminator. There are reasons why using the discriminator output for 1200 packet is often superior for many hardware TNC/modems that aren't smart enough to compensate for relative tone levels (1200/2200Hz) when they are wrong. Soundcard style modems like Direwolf are far more capable and less particular in this regard. If you want to know why the correct audio is important, take a look at this site with pictures and a very simple explanation.   https://www.febo.com/packet/layer-one/transmit.html

I know I flog that site and will continue to do so because if everybody using packet read that article and implemented correct audio practices there would be a lot more stations having much greater reliability with packet radio/APRS communications. If I sound like a grumpy old man, I am. I've been involved with packet since about 1985 and the biggest single factor for people's
woes and failures with the mode remains wrong audio setup.

For transmit when using the rear socket, the radio will probably select the right option depending on whether you choose 1200 or 9600 for the speed in the radio setup, like my Kenwood TM-V71A does.

Ray vk2tv

On 24/6/20 3:17 am, Jim Lange wrote:
You need to use the 1200 port on the radio. The other is for high speed packet and won’t work with a TNC that isn’t made for it. Otherwise all is good. 

Sent by me


On Jun 23, 2020, at 13:13, Al Massaro <almassaro1@...> wrote:

OK I am thinking of trying a TNCPi with a ft 7900r, the pigate site shows the pinout for a FT 2800/2900 using the mic port. My question is my 7900 has a rear data port why can't I use it? Her is a comparison of the 28/2900 mic pinout and my plan for my 7900. Do I need to figure out and use the pinout for the 7900 (MH48A6J) MIC PORT instead? Below left mic pinout from website, Below right my plan for 7900.


 

Another issue which may be important is some radios require more audio voltage/level going into the data port.  The NinoTNC has two selectable output ranges, high, for data radios, and low, for microphone audio, for this very reason.  NinoTNC has 1200, 2400, 4800, 9600 baud DSP modems built in so it needs to support a wide range of radios.  
   Tadd - KA2DEW

On Jun 23, 2020, at 6:29 PM, Ray Wells <vk2tv@...> wrote:

That's not quite correct. For receive, the difference between the 1200 and 9600 ports on the rear socket is that the former has de-emphasised audio while the latter has "flat" audio from the discriminator. There are reasons why using the discriminator output for 1200 packet is often superior for many hardware TNC/modems that aren't smart enough to compensate for relative tone levels (1200/2200Hz) when they are wrong. Soundcard style modems like Direwolf are far more capable and less particular in this regard. If you want to know why the correct audio is important, take a look at this site with pictures and a very simple explanation.   https://www.febo.com/packet/layer-one/transmit.html

I know I flog that site and will continue to do so because if everybody using packet read that article and implemented correct audio practices there would be a lot more stations having much greater reliability with packet radio/APRS communications. If I sound like a grumpy old man, I am. I've been involved with packet since about 1985 and the biggest single factor for people's
woes and failures with the mode remains wrong audio setup.

For transmit when using the rear socket, the radio will probably select the right option depending on whether you choose 1200 or 9600 for the speed in the radio setup, like my Kenwood TM-V71A does.

Ray vk2tv

On 24/6/20 3:17 am, Jim Lange wrote:
You need to use the 1200 port on the radio. The other is for high speed packet and won’t work with a TNC that isn’t made for it. Otherwise all is good. 

Sent by me


On Jun 23, 2020, at 13:13, Al Massaro <almassaro1@...> wrote:

OK I am thinking of trying a TNCPi with a ft 7900r, the pigate site shows the pinout for a FT 2800/2900 using the mic port. My question is my 7900 has a rear data port why can't I use it? Her is a comparison of the 28/2900 mic pinout and my plan for my 7900. Do I need to figure out and use the pinout for the 7900 (MH48A6J) MIC PORT instead? Below left mic pinout from website, Below right my plan for 7900.



Mark Griffith
 

Al,

I use a FT-7900 with my TNC-Pi9k6.  You need to use the 6 pin mini-DIN connector and not the DB-9.  That way, you don't need to change anything when switching between 1200 and 9600 baud except the settings on the TNC and on the radio.  No switching jumpers or cables.

The pin-out you mention on the PiGate site is just for radios that don't have the built-in packet port.  You *could* set it up through the mic and headset ports, but then you are limited to 1200 baud only.

Please let me know if you have any more questions.

Mark
KD0QYN


On Tuesday, June 23, 2020, 12:13:35 PM CDT, Al Massaro <almassaro1@...> wrote:


OK I am thinking of trying a TNCPi with a ft 7900r, the pigate site shows the pinout for a FT 2800/2900 using the mic port. My question is my 7900 has a rear data port why can't I use it? Her is a comparison of the 28/2900 mic pinout and my plan for my 7900. Do I need to figure out and use the pinout for the 7900 (MH48A6J) MIC PORT instead? Below left mic pinout from website, Below right my plan for 7900.


Mark Griffith
 

The TNC-Pi9k6 has a voltage range that is software select able from 24mv to 3000mv (3 volts).  This range works with most radios, but I've personally only tried a small set.

There is also a 2400 baud mode, but I have yet to find a radio that will work with it.  It's nice to have all those speeds, but then finding a radio that it can work with is another matter entirely.

I have a couple NinoTNC boards (ver2) that I need to start more earnest testing.  Too many other spring time things are in the way, planting the garden, keeping up on the grass cutting, smoking meat, eating it, etc etc etc.  Oh, and naps.  Naps are important.  *Sign*, retirement is such a tough life.

Mark
KD0QYN


On Tuesday, June 23, 2020, 6:07:13 PM CDT, Tadd KA2DEW in NC via groups.io <tadd@...> wrote:


Another issue which may be important is some radios require more audio voltage/level going into the data port.  The NinoTNC has two selectable output ranges, high, for data radios, and low, for microphone audio, for this very reason.  NinoTNC has 1200, 2400, 4800, 9600 baud DSP modems built in so it needs to support a wide range of radios.  
   Tadd - KA2DEW

On Jun 23, 2020, at 6:29 PM, Ray Wells <vk2tv@...> wrote:

That's not quite correct. For receive, the difference between the 1200 and 9600 ports on the rear socket is that the former has de-emphasised audio while the latter has "flat" audio from the discriminator. There are reasons why using the discriminator output for 1200 packet is often superior for many hardware TNC/modems that aren't smart enough to compensate for relative tone levels (1200/2200Hz) when they are wrong. Soundcard style modems like Direwolf are far more capable and less particular in this regard. If you want to know why the correct audio is important, take a look at this site with pictures and a very simple explanation.   https://www.febo.com/packet/layer-one/transmit.html

I know I flog that site and will continue to do so because if everybody using packet read that article and implemented correct audio practices there would be a lot more stations having much greater reliability with packet radio/APRS communications. If I sound like a grumpy old man, I am. I've been involved with packet since about 1985 and the biggest single factor for people's
woes and failures with the mode remains wrong audio setup.

For transmit when using the rear socket, the radio will probably select the right option depending on whether you choose 1200 or 9600 for the speed in the radio setup, like my Kenwood TM-V71A does.

Ray vk2tv

On 24/6/20 3:17 am, Jim Lange wrote:
You need to use the 1200 port on the radio. The other is for high speed packet and won’t work with a TNC that isn’t made for it. Otherwise all is good. 

Sent by me


On Jun 23, 2020, at 13:13, Al Massaro <almassaro1@...> wrote:

OK I am thinking of trying a TNCPi with a ft 7900r, the pigate site shows the pinout for a FT 2800/2900 using the mic port. My question is my 7900 has a rear data port why can't I use it? Her is a comparison of the 28/2900 mic pinout and my plan for my 7900. Do I need to figure out and use the pinout for the 7900 (MH48A6J) MIC PORT instead? Below left mic pinout from website, Below right my plan for 7900.