[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: PSK-1 & FT-847 doppler auto correct function

> 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?


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

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

*     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 

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.


Tim - N8DEU
Huntsville, Alabama

Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org