PSK31 with Homebrew Sound card to Radio
Interface
(G3PLX)
BPSK31 (Binary Phase
Shift Keying) F1B
Hardware: Assemble hardware, QST schematic, July 2000 and
instruction below.
Radio: Set: All IF Filters OFF (or as wide as possible)
Set: Audio RF to MAX
Set: SQL to minimum
Set: VFO to 14.070
Set: AF volume before “Reduce Audio Level”
PSK31 software indication.
Set: Transmitter output POWER to ¼ the
manufacturer’s max. RF power output,
20 watts or less is a good
setup for a 100 watt transmitter.
Set: Mode to USB
Set: Processor to OFF and SWR ON
Set: Adjust Tuner 1:1 with the
normal output on CW
Set: Set ALC ON and SWR OFF
Speak into Mic, adjusting Mic control so that ALC doesn’t occur above the the
ALC zone
indicator. (use Dummy Load) Disconnect the Mike.
connect
antenna
Adjust Tuner for 1:1.
Set: SSB Slope tune controls OFF. Adjust (to eliminate noise) after
an
operational
freq. Has been selected
ALC can remain on tocontrol drive limit.
Proposed
160 1.838 1.838 1.8121 To 1.840
75 3.58015 3.518 3.5801 To 3.620
40 7.03515 7.070 7.0701 To 7.100
30 10.139
10.139
10.137 To 10.140
20 14.07015
14.070 14.080 To
14.095
17 18.10015
18.109 18.100 To
18.105
15 21.08015
21.070 21.070
To 21.100
12 24.919
24.919
24.200 To 24.925
10 28.120
28.120
28.120 To 28.12015
6 50.000
2 144.000
LSB SPECTRUM ANALYZER USB
14076.6 - - - - - - - - 14080.0 - - - - - -
- - 14083.3
< 3.3KHz > < 3.3KHz >
Can
Receive within
3.3KHz
Can
Transmit within 2.5KHz (Filter) <14080.3 to 14082.8>
Computer setup:
a.
Cable Aux. & Spkr. & RST to
radio
b.
My Computer
control panel: Click: System & Device Manager & Port & Flow:
Set: Flow to: Hardware control or Xon/Xoff control
Close any Program running in the
Background that is using COM PORT-1.
NOTE:
Some Programs will leave RTS HIGH after closing the Program. This will put the
transmitter in
transmit, so the RTS must be put to a LOW by restarting the computer.
c.
Restart Computer:
Select: START – RESTART. RTS can be forced HIGH also by double clicking
XT.
Select: Audio PCI Mixer from Task Bar and select/check Aux. Or (MIC)
Select: PSK31 DigiPan
Program.
Set: DigiPan
– Mode to: BPSK
Configure : Personal Data
: Serial Port
COM PORT-1
: Band Frequencies & USB
d. Ensoniq SOUND
CARD RECEIVE (to adjust audio into
Sound Card)
Select: CONFIGURE/SPECTRUM DRIVE from Audio PCI mixer on Task Bar
Select: AUXILARY BALANCE and
select/check "box"
Adjust: AUXILARY BALANCE to
middle
Adjust: AUXILARY BALANCE VOLUME to
produce speckled Blue (noise) background in
SPECTRUM
WINDOW. (Black or Dark-Blue background indicates low receive
Signal - Yellow on Blue
indicate a high receive signal)
e. Ensoniq SOUND CARD TRANSMIT (to adjust audio from Sound Card)
Set Cursor: to a freq. not in use
(approximately in middle of Band)
Select: CONFIGURE/TRANSMITTER DRIVE
Set: WAVE BALANCE to middle (DIGITAL AUDIO MIXER
.WAV PLAYER)
Set: WAVE BALANCE VOLUME to 3 increments from
bottom (CQ July 2000 p73)
Set: VOLUME CONTROL VOLUME to 3 increments from
bottom
Select: MODE/TX (Radio will
transmit, take precautions)
Adjust: VOLUME CONTROL’s
VOLUME, stopping as transmitter output power
reaches
MAX (20w) and run with NO ALC indicating occurring.
(QST May 2000 p42)
Note: An O-Scope (Station Monitor)
is preferred over the radio power indicator.
Select: OK (stops transmission).
PSK31 setup is now complete
Note: With the use of a Data Switch
Box, the computer
maybe used
for several communication programs i.e. Packet (Pakratt-XPWare);
MFSK Stream; PSK31; AMSAT WiSP; APRS Aprsplus; SSTV Chroma Pix and
Digital Camera.
Due to the operation of the computer’s COM serial interface
Card, switching from one COMM
program to another will cause a problem.
Example: XPWare
is being used on COM 1 and PSK31 is now required. The radio
transmitter
will not lockup into the transmit mode if the following steps
are
followed:
1. Close all programs
2. Restart computer
3. Select the DigiPan program
5. Switch the Data
Switch from XPWare to PSK31
Optional: Calculating output power with a scope:
1.
Measure PEP (peak
envelop power) i.e. 250v
2.
PEV (peak envelop
voltage) = 250/2 i.e. 125v
3.
RMS (route mean
square) = 125v x .707 i.e. 88.4v
4. P= E2/R P= (88.4)2/50 ohms P= 7810/50 =
156 watts
NOTE: R-value determined by 50ohm tester
seeing a 50-ohm antenna load
Station Monitor setup: (TX Signal NOT
TUNE)
Bands Scope – FAST
Function – MONI
RF ATT - MIN
Horz. Sweep 10-100Hz
.5 gradations = 10 watts @ RT
ATT MAX
3 gradations = 100 watts @ RT ATT pos. 1/2
NOTE: PSK31 transmit MUST be
TX not TUNE!
Assembled Hardware:
Parts required to
build an Sound-card to radio interface:
1. Sound
Card cable Radio Shack part number 42-2387 ($3.99 each buy 2ea.)
2.
Radio ACC DIN plug for: (select one)
ICOM 6 pin, Radio Shack part number 274-020 $1.99
Kenwood 13 pin, AES $9.95
WIRE: Radio connector ACC: (to operate XT & RX)
p3 to
Sound Card Line In
p11 to
Sound Card Line out
p13 to
July 2000 & QST August p.55
p8
WIRE: Radio connector ACC: (to operate RX only)
p11 to
Sound Card Line out
3.
DTR to PTT interface to key transmitter:
(Note: Some Hams are using VOX or
manual control instead of building
interface)
1. Project Box Radio Shack part 270-283 $3.99
2. Radio Shack transistor MPS2222
(2N2222) $ .89
3. Radio Shack 2.7k resistor part RSU 11344942 $ .49
4. Radio Shack 1N4001 diode part 276-1101 $ .49
5. Radio Shack RS-232 male part 276-1547 $1.49 (computer
6. Radio Shack RS-232 Hood part 276-1536 $1.99 (computer
7. Radio Shack cable part 278-777 $8.99 (PTT/DTR)
Optional: Beads - www.buxcommco.com or
AMIDON Co.
Sending PSK31 PICTURES (
DigPix) :
Download Necessary Utilities to PSK31
Folder/Directory:
Encoding Utility:
http://ftp.nsys.by/pub/soft/mac/binhex.exe
Picture Viewing & Editing Utility:
http://members.home.com/rsimmons/irfanview/
Decoding Utility:
Decode Shell Extension v4.6
http://www.funduc.com/explorer_extensions.htm
Operation:
Resample a Photo to be transmitted:
Click on IrfanView Photo Program
Click File – Open
and select a stored photo on C Drive
Click OK
Click Image –
Resample – Select 35X51 Pixel (20%X20%)
Click File – Save as
digpix .jpg Directory-
C:\Progra~1\PSK31
Click OK
Convert Photo from a .jpg File to a Text File:
a.
Click on PSK31 Directory
b.
Click on
BINHEX.EXE in PSK31 Directory
c.
Click on
BINHEX F-2 (BIN2HEX convert Binary to HQX)
d.
Click on digpix.jpg File
e.
Click OPEN (digpix.jpg file
converted to .hex TEXT File)
f.
Click EXIT (ALT-X)
the new HQX File is stored in PSK31 Folder
Transmit Photo:
a.
Open PSK31 Program
b.
Left-Click on a
spare MACRO: MACRO Title type DigPix;
c.
In MACRO text block, type <digpix.hqx> click
OK
d.
In PSK31 Transmit window, type Photo being sent next, standby to save RX
text.
e. Click Transmit, after message has been sent,
Click Transmit to stop
f. Click on MACRO title DigPix
( digpix .hqx File will be
added to TX window)
g. At the end of MACRO’s Data, type:
END de AA3EU – Please save RX text File
as digpix.hqx
h. Click on TX to transmit photo
i. Click on TX at the end of transmission (to
end transmission).
Receive
Photo:
a.
Click File
b.
Click Save RX text
as digpix.hqx
(saved to PSK31 directory)
c.
Click on PSK31
Directory – BINHEX .EXE - BINHEX
F-3 (converts HQX to Binary
File)
d.
Click exit
View
Photo:
a.
Open Irfan Viewing Program
b. Open digpix.jpg File in PSK31
directory and view
DigPic:
Original Photo= Photo File .jpg
– W166xH244 pixels
Resized Photo= Photo File .hqx
– W35xH51 pixels
A picture row is 60+/- characters per-row X 80
rows
digpix.TXT (photo file) = 2.94 KB
Transmit time= 13 minutes
Note: Resize W & H to lower or
increase transmit time.
Download free software:
DigiPan PSK31 http://members.home.com/hteller/digipan
DigiPics free
software:
PSK31 picture sending/receiving
software:
Encoding Utility: file:
http://ftp.nsys.by/pub/soft/mac/binhex.exe
Decoding Utility: file
Viewing Utility: file:
http://members.home.com/rsimmons/irfanview
Instructions:
http://members.home./hteller/psk31pictures/
Other PSK program software: DigiPan v1.2 – Logger v7.07b – Zakanaka
v1.24
W1sqlpsk v5.0.0.1 - HamScope v1.54 MixW v1.45
PSK31 REFLECTOR: [email protected] (type
SUBSCRIBE PSK31)
www.n2ty.org
Operating:
You are now ready to operate
PSK Mode. They call it the "
see why when you look at the Spectrum Display, Computer
Monitor; you may see 10 to
20 stations (yellow
vertical stripes moving down the Monitor; these are stations
transmitting on different frequencies. All you do is POINT &
CLICK to move from one
freq (one Station) to the next. Once the radio is set to a
BAND you don't use the
radio VFO any more; you can hop, POINT & CLICK from one
freq. to the next. You can
send from the keyboard, from MACROs,
from Files or send photos from a File.
With DigiPan
software you have 24 MACRO's. If you makeup MACROS to
answer all possible
information, there is no typing required. Using VOX is a problem;
you will see many
transmitting stations dropping the first three characters of your
call when they respond. When they click on XM, the software
starts sending the MACRO
message before the
transmitter starts sending (race condition with async
data
transmission). If you are going to use VOX, not the PTT transistor ckt., I
suggest you
type three space characters at the start of your MACRO.
Some PSK operators are
transmitting 50 watts. 50 watts is a bit much, (like those
Micors & Syntors VHFers). That
is too much power. Some say they are transmitting
1 watt. Don't see how they can determine 1 watt without using
a scope
and working the math.
The word is out, PSK31 is
FCC approved and Hams are switching from CW, RTTY, HELL,
CLOVER,
PACTOR, G-TOR & AMTOR Modes to PSK. More the merrier because a
PSK31/BPSK
Station only takes 31Hz of
Bandwidth. It would be possible to view 100 stations at a
time on my Monitor with one VFO setting. DigiPan software allows for a great viewing
area of a Band.
Recommendations:
Don’t use the sound-card’s MIC
input, use the auxiliary output of the receiver which doesn’t
vary in level with speaker volume.
Do not connect the
sound-card output direct to the mike input. Interface the input with a
100K in
resistor in series and 1K in parallel.
If the auxiliary input is
used, mute the mike so others on the Band don’t hear your
Shack noise.
Do not use a speech
processor with psk31; it will generate distorted products close-in which
will make a psk31 signal much wider spectrum-wide (500Hz)
then it should be (31Hz).
Always use USB for psk31,
QPSK in LSB will invert the signal and with all Stations using
USB it is easier to see
where to QSY to, with both Stations seeing the same audio spectrum.
It’s OK to let the
transmitter ALC line operate on psk31. The ALC line will control the drive
level without clipping in the same way as it does in voice
operation.
The phase scope indicates
the receive signal is BPSK or QPSK and the quality of the link.
The phase scope shows the
phase shift modulation and amplitude of the carrier. An unmodulated
carrier has no phase shift and shows as a line vertically up
from the center; a stronger carrier
gives a longer upwards line. An idle signal has 180 degrees
shift phase-shift modulation and so
shows as a line vertically downwards from the center. A
vertical line across the diameter is a
text signal, a cross pattern instead of a data; vertical
line shows that the signal is QPSK.
The signal quality the
comparison between the wanted sidebands at +/-15Hz (idling signal) and
unwanted sidebands at +/-45Hz from center freq. third order
modulation. False readings maybe:
another signal too close; a week signal; distortion from the
receiver caused by: AGC or poor
quality output.
References:
RadCom Dec. 1998
ARRL General Counsel
approved PSK31
QST Apr. 1999 p50 New Digital Modes
QST May 1999 p41 “psk31 101”
QST Jun. 1999 p87 Reflector
QST Aug. 1999 p51
QST Nov. 1999 p75 psk31 audio schematic mod.
QST Dec. 1999 p35
QST Mar. 2000 p55
QST May 2000 p42 Dirty Signals Set ALC to read “0”
QST Jun. 2000 p31
QST Jul. 2000 p81
CQ Jul. 2000 p71 psk31 schematic
QST Aug. 2000 p.55 psk31 schematic, (switching ckt.mod.)
QST Oct. 2000 psk31 on 2m FM
QST Jan. 2001
p33 MFSK/PSK31; p49 Test;p50 HF Digital;p58 mobile;
p52 PSK #1 Mode
QST Feb. 2001
p25 p42 IF notch filters+SSB wideband filter for
point click tuning
QST Feb. 2001
p88 psk31 distortion
QST Mar. 2001
p37 Warbler p106 PacTerm
QST May 2001 p9 psk31 is head of other Digital Modes
FCC Rule Book p.4.29 "is psk31 legal"
Joe Mettle sends: