digital communications - marcmtnarc.org/index_htm_files/digital communications.pdf · digital...
TRANSCRIPT
Digital Communications
PSK31
Bob Wilton – KF5TPQ
Digital Communications – PSK31
Digital Communications Overview
PSK31 – What is it?
Hardware Considerations
Software Considerations
Ham Radio Deluxe – DM780
Configuring
Lets look at a QSO
Other Resources
Questions (Ask questions anytime)
Digital Communications
Computers and digital data
Text data
1’s and 0’s, bits, bytes, characters, variable character sets
Transmission modes – AFSK, PSK (frequency vs phase shifting)
Bandwidth
Signal to noise ratio
So many Operating modes
RTTY, PSK31, JT65, JT9, Winlink2K, Olivia, Opera, Hell, and more
PSK31 and Winlink2K (Georgia ARES)
Digital Bands
PSK31
Why PSK31 ?
Widely used and just a good place to start
BPSK (Binary Phase Shift Keying – 180 degrees)
Low power: 5 – 40 watts (lower the better)
100% duty cycle
ALC and IMD considerations
Bandwidth approximately 31 hz
Throughput – up to about 50 words per minute
Varicode character set
Variable length, e = 11, E = 1110111
Works well in poor noise and poor propagation conditions
PSK63 and PSK125
PSK31 Frequencies
10 Meters – 28,120
12 Meters – 24,920
15 Meters – 21,080
17 Meters – 18,100
20 Meters – 14,070
40 Meters – 7,080
80 Meters – 3,580
Hardware Considerations
HF Transceiver
Computer (or laptop or even a tablet)
Interface
Audio and ptt
Line out
Sound card
Line in
Mic Audio out
Hardware Considerations
Homebrew
Line out
Sound card
Line in
Audio out
100k 1k
Mic
22k
2N2222
1N4148PTT
Serial
RTS
PTT via serial port
(RTS, DSR, or similar
signal line)
Hardware Considerations
Mic
Audio out
Sound
Card
Interface
West Mountain Radio RIGblaster
(about 5 types)
MFJ make a few
MicroHAM
RigExpert
SignaLink USB Interface
Many more, inc many homebrew
designs starting at about $10
Software Considerations
Windows, Mac, Linux, IPAD, Android
Multiple “FREE” software programs available
Ham Radio Deluxe – DM780
Digipan
Fldigi
Hamscope
WinWarbler
And more………….
Ham Radio Deluxe version 5 - Free
Ham Radio Deluxe - HRD
Ham Radio Deluxe – DM780
Ham Radio Deluxe – DM780
Ham Radio Deluxe – DM780
Ham Radio Deluxe – DM780
Ham Radio Deluxe – DM780
Ham Radio Deluxe – DM780
Ham Radio Deluxe – DM780
Ham Radio Deluxe – DM780
PSK63
PSK125
Ham Radio Deluxe – DM780
Additional Resources - PSKReporter
Additional Resources – HDRlog.net
Additional Resources – QRZ.com
Additional Resources - Google
Digital Communications – JT65
Digital Communications - JT65
CQ N0RQ EM13 (I CQ)
N0RQ W1AW FN31 (he answers with his grid)
W1AW N0RQ -06 (I send signal report)
N0RQ W1AW R-13 (he sends Roger and my signal report)
W1AW N0RQ RRR (I acknowledge receipt of his report)
N0RQ W1AW 73 (he sends a standard or freeform 73)
10W DIPOLE 73 (I send a freeform or standard 73 – contact
is over)
Digital Communications – JT9
