Re: [amsat-bb] PSK-1 & FT-847 doppler auto correct function

["Tim Cunningham" <tim_cunningham@xxxxxxxxxxxxxx>]

> I am having trouble with the PSK-1 doing the automatic doppler
> correction via mike clicks to my FT-847.  I've wired up the cable and
> double checked the wiring.
> 
> When the PSK-1 "nudges" the FT-847 it starts scanning up or down, rather
> than just moving slightly up or down in frequency.
> 
> Any ideas?


Rob,

You may have the clicks set too fast or active in the inverse
state.

Here are my settings that I use on the PSK-1 and FT-847
combo:

 
***********************************************
*     P a c C o m m  P S K   M o d e m        *
*    PSK Firmware version 2.10  CSUM: 2A05    *
*  (C) 1990 Digital Signal Sys, 1991 PacComm  *
***********************************************
 
<1> Mode:                 400bps Telemetry
<2> Modem:                In-Line (PSK modem)
<3> Joint/Split:          Joint (VHF RX, VHF TX)
<4> AFC:                  LSB (Tone freq decreases with decreasing RX freq)
<5> Mic-Click Sense:      Active-Low
<6> Clicks-per-Step:      One
<7> Maximum Step Rate:    12 per second
<8> DCD Output Sense:     Active-High
<9> RS232 Speed:          1200 8N1
<A> Help:                 



Items 5, 6, and 7 affect the operations of the microphone
UP/DOWN function. I hope this helps you. 

Wait a minute...  I made a hardware modification to my 
PSK-1 at some point to eliminate the need for pull-up
resistors on the UP/DOWN lines. You can replace U23 
(74HC06 high voltage open collector inverter) with a 
74HC14 that is pin for pin compatible.  The 74HC14 
eliminates the need to add pull-up resistors to these 
lines. I performed this modification back when I had an 
FT-726.

The 74HC06 will tolerate up to 30V on its output and the
74HC14 is limited to tolerating an absolute maximum
of 6.5V when used in the PSK-1 and slightly less output
current than the 74HC06. However, the 74HC14 works 
fine with the FT-726, FT-736, and the FT-847.





73's,

Tim - N8DEU
Huntsville, Alabama


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