Rob is right here (sorry for the confusion).? I did
have them reversed BUT it's the "DATA IN" signal that also needs
the ability to enable or disable the application of pre-emphasis
if your radio supports this.? For say Kenwood v71/d710 models,
here is a thread about it:
??
/g/VARA-MODEM/topic/74742391
Ultimately, when in doubt, assume your radio is applying the
emphasis / de-emphasis to your signal which is the CORRECT choice
for 1200bps packet used with APRS, classic connected packet, etc.
--David
KI6ZHD
On 04/28/2022 08:28 AM, Rob Giuliano
via groups.io wrote:
toggle quoted message
Show quoted text
The Data Jack (6-pin
mini-DIN) on radios does NOT have a 9600 baud TX pin.
There are 6 pins in the
jack:
1??? PKD (Data In)
2??? GND
3??? PTT
4??? RX9600
5??? RX1200
6??? SQL
The TC path is the same for
either baud rate.
Hello Neil,
I am looking at the received
audio coming back from the kenwood radio in
audacity(first program I tried), and when I look at
the transmit tones, it appears that my higher
frequency is way down compared to the lower
frequency.? Changing the playback volume doesn't
appear to solve this.? The output looks the same when
normalized(which audacity seems to do automatically).
Am I looking at this correctly?
I think you you're seeing the effect of pre-emphasis or
the lack of it.? When you connect your packet equipment
to your radio, more basic radios can only be connected
using their microphone port or possibly a "1200 bps"
packet pin.? Those those signals will have pre-emphasis
added to them and are transmitted over RF.? More
advanced radios or modified radios have a "9600 bps" pin
that does NOT add a pre-emphasis stage to the signal
before it's transmitted over RF.?
Pre-emphasis is already covered on
but also has good descriptions here:
??
--David
KI6ZHD
