[Yaesu] More on 10.151.51 and Ft-920

Fri, 9 Apr 2004 18:34:12 -0400

> > 
> > HOWEVER, with the radio set at the proper freq.
> > (10.151.51) I cannot transmit. The radio goes into 
> > error mode because it thinks I'm outside the band. 
> > (At least I think that is the problem!)
> > 
> > PKT DISP _ menu U-45 is set to -2.125
> > PKT FREQ _ menu U-46 is set tuo 2125-L
> > 
> > The APRS stuff is carried on in LSB as I understand
> > it -- and it must be right, because I am receiving 
> > stuff correctly.
> > 
> > What are the issues here, and how do I get around
> > this.

I assume APRS is using HF packet standards (300 baud and 
200 Hz shift) instead of RTTY standards (45.45 baud and 
170 Hz shift). I am also assuming the a channel center 
frequency is 10.148.30 since most of the early HF packet 
work used the old standard 1600/1800 Hz tones which, with 
an LSB dial frequency of 10.150.00 would place the center 
at 10.148.30 (and the majority of keying energy between 
10.148.00 and 10.148.80 - approximately 600 Hz bandwidth). 
If your TNC/TU uses 2110/2310 Hz tones (common):
 Set Menu U-46 (Packet Subcarrier Frequency) to: 
 2210 USB (2210-U)
 Set Menu U-45 (Packet Display Offset) to: +2210 
If your TNC/TU uses 1600/1800 Hz tones: 
 Set Menu U-46 (Packet Subcarrier Frequency) to: 
 1700 USB (1700-U)
 Set Menu U-45 (Packet Display Offset) to: +1700 
Tune the rig so it shows the channel CENTER frequency: 
(10.148.30) instead of the (suppressed) carrier frequency. 
You will need to select "DATA-USB" as your operating mode, 
set the AFSK/FSK switch on the back of the rig to AFSK and 
feed AUDIO TONES from your TNC to pin 1 of the DATA DIN plug 
on the back of the radio. 
73, 
 ... Joe, K4IK 