Ham HF Digital Modes For the beginner Guy, WB5UAA
History (Can t know where we are or where we re going if you don t know where we ve been!) Wired telegram 1830 s, DC circuit with long wires On/Off keying; dots/dashes (Samuel) Morse code Really, it was Alfred Vail, who worked with Samuel Morse Year: 1844, 44 miles of wire, Washington DC to Baltimore, WHAT HATH GOD WROUGHT? Mid to late 1800 s action at a distance was discovered a spark caused sparks in nearby devices This led to wireless telegraph Spark Gap connected to an aerial (wire hanging up high), caused a wide-band noise (just like lightening) (in the low end of the spectrum by today s standard) which could be detected with a diode receiver some distance away First carrier wave (was basically controlled lightening ) Hams were relegated to the useless wavelength of 200 meters on down as a result of the sinking of the Titanic and the Radio Act of 1912
Radio Act of 1912 (started licensing) Regulation 1: Every station shall designate a certain definite wave length as their normal sending and receiving wave length Normal wave length defined as 1600 meters to 600 meters or 187 Khz to 500 Khz in today s terms Regulation 3: 1 st spectral purity defined: A pure wave is of such character that the energy is radiated in two or more wave lengths, more or less sharply defined, as indicated by a sensitive wave meter, the energy in no one or the lesser waves shall exceed ten per centum of that in the greatest Or, harmonics must be 10 db down in today s terms 10% (linear) works out to 10 db (logarithmic) in this case Today, harmonics must be 43 db down (or < 0.005%) to be FCC type accepted
Radio Act of 1912 (continued) Regulation 6: SOS defined Regulation 7: (paraphrased) and also you re allowed to tune your radio for maximum harmonics and splatter when sending a distress signal! Regulation 14: First regulation stating In all circumstances, except in the case of signals or radiograms relating to vessels in distress, all stations shall use the minimum amount of energy necessary to carry out any communication desired
Radio Act of 1912 (continued) Regulation 15: No private station shall use a transmitting wave length exceeding 200 meters, or a transformer input exceeding 1 Kilowatt penalties of $125 200 Meters on down (or 500 Khz and above) was considered useless frequencies
Radio Act of 1912 (continued) Also, as an FYI, first regulation which makes wiretapping illegal Regulation 19: (paraphrased) it s illegal to eaves drop and publish what you hear, unless the message was intended for you. Punishable by a fine of up to $250 and up to 3 months in jail!
Morse Code First RF Oscillator hissing arc Dynamo-motor system could begin to regulate the frequency Noticed an Electric arc could be oscillated with an LC tuned circuit the first of the tuned oscillators which made frequency more accurate 1912, a vacuum tube feedback ( regeneration ) oscillator which led to the regenerative receiver 1920, the vacuum tube feedback oscillator become the basis for radio transmission
On/Off Carrier (wave) Keying Di Di Dah Dit F
The carrier wave and Modulation Modulating Signal Amplitude Modulation Frequency Modulation
Amplitude Modulation has an Upper Side Band and a Lower Side Band
Filter one side of AM and you have SSB
Some terms When looking at the digital modes of today, you have to look at it from two perspectives Encoding - How a 1 or a 0 is placed on the carrier wave Frame Format - What series of 1 s and 0s represent each letter in the alphabet CW (The first of the digital modes) Encoding: On/Off Keying, Dots/Dashes Frame Format: Morse Code A frame Di dah B frame Dah di di dit C frame Dah di dah dit Timing based on the length of the dit 1/3/5
AM/FM/SSB Encoding Audio frequency superimposed on to the carrier frequency By varying either the amplitude or frequency with the audio frequency Frame Format This term doesn t really apply to AM/FM/SSB since this term only applies to binary 1 s and 0 s
2nd Digital Mode - RTTY Radio Teletype (RTTY) Encoding: two audio tones used (instead of your voice) as the modulated wave superimposed onto the carrier wave Mark tone 2,125 Hz This is a digital binary 1 Space tone shifted down 170 Hz (1955 Hz) or down 425 Hz (1700 Hz) or down 850 Hz (1275 Hz) This is a digital binary 0 Timing based on bits per second Frame Format: Originally 5-bit Baudot Code but now 7 or 8 bit Asynchronous ASCII
Serial Bit Stream encoded onto a carrier wave using FM 1 0 0 1
Original 5-bit Baudot Code + = Mark - = Space A 10000 B 00110 C 10110 D 11110 E 11000 Etc.
American Standard Code (for) Information Interchange (ASCII)
Amateur Teleprinting Over Radio (AMTOR) Derived from SITOR (Simplex Telex Over Radio) A commercial standard Improved RTTY by incorporating an Error Detection or Error Correction Technique Each character is 7 bits, each character has 4 mark and 3 space bits; if the received code doesn t match the 4:3 radio, the receiver assumes it s an error and generates a automatic repeat request No longer used today
Automatic Packet Reporting System (APRS aka packet radio ) Encoding: Most often Frequency Shift Keying (FSK) Note: AFSK fed into an FM transmitter *is* FSK Frame Format: First to Packetize characters (bytes) instead of bits The term Frame Format really begins to apply with this mode Based on X.25 A commercial standard The APRS standard is AX.25 (Amateur X.25) Address fields use Ham Call Signs instead of digital addresses It started off as a broadcast protocol, but a chat mode was added to get around that legality Version 2.2 has been in effect since July 1998 Still used fairly widely today
AX.25 (APRS) Frame Format(s) Three types of AX.25 Frames -Information (I) Frame -Supervisory (S) Frame -Unnumbered (U) Frame Flag: basically synchronization bits at the beginning and end of the frame Address: Source/Destination Addresses (Ham Callsigns) Control: Identifies the type frame it is (Layer 2) PID: Identifies which kind of Layer 3 protocol, if any, is in use Info: the data (default is 256 bytes of data) FCS: Frame Check Sequence (CRC calculated to determine if frame has become corrupt)
Typical APRS Displays
Typical APRS Display
Slow Scan TV (SSTV) (not really a digital mode, but merits mentioning) Encoding: Varying tones across the audio spectrum which represent color and intensity Frame Format: The TV Picture Starts with a calibration header consisting of 300mS tone at 1900 Hz, a 10mS break at 1200 Hz, another 300 ms tone at 1900 Hz, followed by a digital Vertical Interval Signaling code which identifies the mode used Several modes which vary in BW/Color, lines and columns, and time to send an entire picture.
Slow Scan TV (SSTV) Common SSTV Modes
Slow Scan TV (SSTV)
Slow Scan TV (SSTV) Horizontal Vertical 1 2 3 4 5 6 7 8 9 10 11
Phase Shift Keying (PSK) A different way of encoding data on a carrier wave The Phase of the carrier wave is changed to represent 1 s and 0 s This really starts to approach the mathematical limitations of how much data (how fast ) you can place on a carrier wave Nyquist Sampling theory is the old way of thinking about placing info on a carrier wave
Old view of how to digitize an analog signal Degraded signal can be fixed with error correction Can also be compressed for less bandwidth However, there s limit to how fast you can sample the signal wave 28
Nyquist Theory Sampling frequency must be 2 times or greater than the signal frequency in order for the receiver to be able to accurately reconstruct the signal frequency
Phase Shift Keying (PSK) One full cycle of a carrier wave has phases which can be shifted to represent 1 s and 0 s Couple ways to represent Phase Shift Keying
Phase Shift Keying (PSK) Two basic encoding schemes Binary phase-shift keying (BPSK) Quadrature phase-shift keying (QPSK)
Binary phase-shift keying (BPSK)
Quadrature phase-shift keying (QPSK)
BPSK and QPSK Waveforms 180 degree (pi) shifts and 90 degree (pi/2) shifts
PSK31 Encoding: BPSK or QPSK Frame Format: Varicode Character Set Serial character stream like RTTY Timing is 31.25 bits per second Varicode, like morse code (and the arrangement of the QWERTY Keyboard) uses fewer bits to represent letters/characters most often used and more bits to represent letters/characters least often used PSK31 is still very popular amateur mode today
PSK31 Varicode Set Partial set (36) shown here, 130 varicode characters are defined
MT63 Encoding: MFSK, 63 tones Frame Format: Originally Varicode, now base128 By the way, this is the preferred mode for EMCOMM, using Narrow Band Emergency Messaging System (NBEMS), which is implemented using FLDIGI and FLARQ, through VHF/UHF radios
Base128 6-bit Character Set
Hellschreiber Encoding: facsimile based (similar to SSTV, but black and white only) can be PSK, FM, Two-Tone, Concurrent or Sequential Multitone Frame format: Vertical scans lines going from left to right; two type-written line image
PACTOR An evolution of both APRS and AMTOR APRS ( Pac ket Radio) and AM TOR Encoding: FSK (with ARQ for error detection/correction) Frame Format: ASCII (with Huffman Compression) and a 1.25 second cycle time Sounds like crickets when two stations are connected
PACTOR Huffman Compression Partial list of ASCII with Huffman Compression
WinLink Global Radio Email (not a chat mode) Encoding: 93.75 Baud PSK or 46.875 FSK Pragmatic Trellis Code Modulation (PTCM) with FEC Frame Format: Uses WINMOR, a state oriented communications protocol (which uses and compliments PACTOR) Accepts/transmits TCP/IP POP/SMTP (internet) emails Can use MIME attachments, but you should probably stay away from that because it can make the file transfers very LARGE This, too, sounds like crickets when two stations connect
Pragmatic (dealing with things sensibly and realistically in a way based on practical rather than theoretical considerations)
1-dimensional Trellis Diagram (to make visualization easier ) - 1 st created in the 70 s - Noticed in the 80 s for use in telephone modems when the internet started to proliferate - Idea is to group symbols into a tree-like structure, then separate into limbs of equal size - Basically a convolutional code of rates (r, r+1) - Algorithm programmed into a computer figures out best codes - Key idea: mapping by set partition which provides for a parity check at each symbol - Most common: 4-dimensional set partition = 2,400 baud X 8 bits/symbol = 19,200 bps
WinLink (WINMOR) States
WinLink (WINMOR) Timing (very similar to PACTOR) ISS Information Sending State IRS Information Receiving State
WinLink Global Radio Email (not a chat mode) Encoding: 93.75 Baud PSK or 46.875 FSK Pragmatic Trellis Code Modulation (PTCM) with FEC Frame Format: Uses WINMOR, a state oriented communications protocol (which uses and compliments PACTOR) Accepts/transmits TCP/IP POP/SMTP (internet) emails Can use MIME attachments, but you should probably stay away from that because it can make the file transfers very LARGE This, too, sounds like crickets when two stations connect
THROB Encoding: 9 tones, spaced 8 Hz or 16 Hz apart Multi-Frequency Shift Keying (MFSK) 1 st MFSK used in ham radio? ThrobX uses 11 tones spaced 7.8125 Hz or 15.625 Hz apart Frame Format: Based on tone pairs with several characters represented by single tones. It is defined as a "2 of 8 +1 tone" system, or more simply put, it is based on the decode of tone pairs from a palette of 9 tones. (Can t find the character set ) DTMF Standard telephone frame format 7 tones, tone pairs represent the numbers on the telephone key pad
MFSK16 An advanced THROB Encoding: Based on 16-FSK (sequential single tone FSK) with Forward Error Correction Frame Format: ASCII or Varicode Spectogram
Olivia Encoding: 2,4,8,16,32,64,128, or 256 Tones (MFSK) Frame Format: 7-Bit ASCII with Forward Error Correction (FEC)
Contestia Encoding: 2,4,8,16,32,64,128, or 256 tones (MFSK) Frame Format: 6-bit ASCII (1 less bit than Olivia) (no upper/lower case letters) (uses ½ the character block size as Olivia) Derived from Olivia, it s a compromise of performance in order to improve speed (twice as fast as Olivia, but not as reliable)
JT6M Encoding: 44-tone MFSK (one is a synchronization tone, the other 43 are data tones ; Sync tone is 1076.66 Hz, the others are spaced at 21.53 Hz intervals Frame Format: each tone represents a character This mode is optimized for 6 meter meteor scatter, but is equally effective with Tropo, sporadic E, and scatter modes of propagation Sounds a bit like piccolo music
Domino Encoding: Improved MFSK (using alternating tone sets of 16 tones odd/even, making detection easier in the sound card) Frame Format: tone pairs represent a character, 63 characters total in the set
DominoEX Encoding: MFSK (18 Tones) Frame Format: Varicode with FEC
Thor Encoding: advancement/adaptation of DominoEX with MFSK16 and FEC Frame Format: Varicode
Week Signal Propagation Reporter (WSPR) Encoding: FSK Frame Format: Callsign, Grid, TX power in dbm compressed into 50 bits Ex: WB5UAA EM51 37 Transmissions happen in even minutes Application logs stations heard and uploads station heard into a central database called WSPRnet, which includes a mapping application WSPR is a QRP/QRPp beacon mode digital communications protocol Not supposed to leave it running unattended, otherwise it meets the definition of broadcast? -- at least that s the current debate which is on going
ROS Encoding: Combination of FHSS (Frequency Hopping Spread Spectrum), DSSS (Direct Sequence Spread Spectrum) and 2G (Second Generation) CDMA (Code Division Multiple Access) using 144 tone MFSK with FEC Frame Format: I don t know, can t find any reference to this Can be used in a beacon mode or a QSO mode Created by EA5HVK (Spain) *Since this is a spread spectrum mode, it is only legally allowed in the 222Mhz (1.25 meter) band and higher here in the U.S.
Golay-Teleprinting Over Radio (G-TOR) *Trademark of Kantronics, Inc. Variant of the Automatic Link Establishment (ALE) protocol (SYN/ACK) (with FEC), the Automatic Repeat request (ARQ) cycle and a new application of the Golay code Golay code is an algorithm capable of correcting up to three errors in a frame Encoding: FSK Frame Format: Synchronous, 2.4 second (regardless of transmission rate) data frames of 192, 384 or 576 bits. A data frame consists of Data, Status, and CRC. Characters are coded using 8-bit ASCII with or without Huffman compression.
Clover Encoding: 4 tones 125Hz wide spaced at 125Hz centers; only one tone present at any time for 8mS. Automatically selects the best modulation format. Reed-Solomon FEC and ARQ. 2DPSM Dal-diversity Binary Phase Shift Modulation BPSM Binary Phase Shift Modulation QPSM Quadrinary Phase Shift Modulation 8PSM 8-Level Phase Shift Modulation SPSM/2ASM 8-Level Phase Shift Modulation, 2-Level Amplitude Shift Modulation 16PSM/4ASM 16-Level Phase Shift Modulation, 4-Level Amplitude Shift Modulation Frame Format: 8-bit digital data can be ASCII (or not) Which allows transferring computer executable files
JT65 Encoding: JT65A uses 65 tones (MFSK) compressed with Reed-Solomon algorithm JT65A, B, and C, differ in the frequency shifts between each of the 65 tones For JT65A, the shift is 2.7 Hz. For JT65B, it's 5.4 Hz. For JT65C, it's 10.8 Hz Frame Format: Varicode 72 bits of information, 306 bits of FEC for a total of 378 bits *Needs ACCURATE time to synchronize 2 minute Transmit/Receive cycle Transmissions start precisely 1 second into a new minute 48 seconds of transmit 12 seconds of silence (time for receive station to decode *all* signals) 48 seconds of receive 12 seconds of silence (time for receive station to decode *all* signals) Complete QSO can take 4 minutes Limited structured messages Only one place to put up to 13 characters of your choice
MSK144 Encoding Minimum Shift Keying (MSK) which is a form of continuous-phase FSK with shift equal to ½ the baud rate can be viewed as a form of Offset Quadrature Phase-Shift Keying (OQPSK) Frame Format As with all WSJT-X modes with FEC, messages are compressed into exactly 72 bits The 72 bit message + 8 bit CRC (80 bit) combination is mapped to a 128-bit codeword using a binary Low Density Parity Check (LDPC) code specifically designed for MSK144 72 bits message + 8 bit CRC + 48 bits of FEC + 2 x 8 bit sync words = 144 bits Designed with Meteor Scatter in mind Needs accurate computer time: 30 seconds of transmitting followed by 30 seconds of receiving
FT8 Encoding: MFSK, 8 tones spaced 6.25 Hz apart Frame Format: Varicode, 75 bits and 12-bit CRC and FEC *Needs ACCURATE time to synchronize 4 times faster than JT65 ~13 seconds transmit, followed by ~2 seconds of silence (decode) ~13 seconds of receive, followed by ~2 seconds of silence (decode) Auto QSO sequence added since you only have ~2 seconds to decide if you want to answer a CQ Complete QSO can take 1 minute
FT8 In the News 8 Feb 2018 Dxpedition Mode being developed Goal: make FT8 contacts at the highest possible rates Dxpedition station is designated the Fox, stations calling are designated the Hounds New mode permits contacts to be completed with as little as one Fox transmission per contact Fox can also transmit up to five signals simultaneously, upping the potential contact rate to 600/hour On-the-Air test March 6 User s guide http://physics.princeton.edu/pulsar/k1jt/ft8_dxpedition_mode.pdf
FT8 In the News Test Results - 6 March 2018 Most Hounds operated as intended, and according to instructions Fox s multi-signal capability worked very well at the tested values, NSlots = 3, 4, and 5. This feature is surely a keeper, and I see no reason not to use NSlots = 5 especially if the Fox is running power A couple bugs found in the software The goal is to have the official release of WSJT-X version 1.9.0 completely ready before the planned KH1/KH7Z DXpedition to Baker Island in June
FT8 In the News Dxpedition Mode test #2-7 Apr 2018 Latest "release candidate" (beta) version of WSJT-X -- now called version 1.9.0-rc3 Please note: DXpedition Mode is not yet ready for 'production' use Temporary test frequencies: 3.567, 7.066, 10.1405, 14.105, 18.095, 21.067, 24.911, and 28.067 MHz Taylor said he stressed that FT8 DXpedition Mode is not ready for routine use "because several operators or groups have been trying, against our advice, to use the not-yet-complete DXpedition Mode in real pileup situations. This misuse of a WSJT-X beta release -- or of code taken from the WSJT-X development branch -- has been counterproductive." "We hope to have a full 'green light' on usage in the fairly near future," Taylor told ARRL.
FT8 In the News Test Results - 7 Apr 2018 Operators learned how to better manage the queues of calling stations Initial results: W1/KH7Z logged 61 stations in 36 minutes A rate of 102 per hour K1JT logged 55 stations in 21 minutes A rate of 157 per hour W7/KH7Z worked 174 stations in 60 minutes A rate of 174 per hour After a program restart, Joe Taylor, K1JT, worked 105 additional stations A rate of 225 per hour! Joe said further progress will definitely be possible Another public test is now in the making but it s very near public release!
All modes briefly covered CW/Morse Code AM/FM/SSB RTTY AMTOR APRS SSTV PSK31 MT63 Hellschreiber PACTOR WinLink THROB MFSK16 Olivia Contestia JT6M Domino DominoEX THOR JT65 MSK144 WSPR ROS G-TOR CLOVER FT8
Summary of Encoding Techniques On/Off Keying; dots/dashes AM/FM/SSB FSK (Frequency Shift Keying) Usually associated with two tones/states, with or without Reed-Solomon or Golay compression at this layer MSK (Minimum Shift Keying) can be viewed as a form of Offset Quadrature Phase-Shift Keying (OQPSK) MFSK (Multiple Frequency Shift Keying) Usually associate with >2 tones/states, with or without Reed-Solomon or Golay compression at this layer PSK (Phase Shift Keying) Binary (2) and Quadrature (4) PTCM (Pragmatic Trellis Code Modulation) (16) PSM (Phase Shift Modulation) (carrier phase is modulated by the signal wave) *Some sound diddly ; some sound chirpy ; some sound musical
Summary of Frame Formats Single Character Morse Code 5-bit Baudot 6, 7 or 8-bit ASCII (with or without Huffman compression at this layer, error correction code) Varicode (with or without Huffman compression at this layer, error correction code) Base128 Tones and/or tone pairs Grouped Characters APRS protocol State Oriented (as opposed to request/response) WinLink
Summary of HF digital modes Four categories (I ve broken them down into) Single character, keyboard to keyboard modes Images Computer processed, Grouped sets of characters sent, then processed by a computer at the receiving end and displayed according to the contents of the frame Some that don t really fit the above categories
Keyboard to Keyboard Modes (Single character typed, single character received) RTTY AMTOR PSK31 MT63 Pactor Throb MFSK16 Olivia Contestia JT6M Domino Thor JT65 MSK144 G-TOR DominoEX FT8 Still popular: RTTY, PSK31 Growing interest: FT8 has replaced JT65
Images Slow Scan TV (SSTV) Hellschreiber (Fax) Still many SSTV and Hell contests scrolling through the contest calendars.
Character groups (Requires computer processing to send/receive) APRS (Automatic Maps, locations) Clover (optimized for transferring files) APRS still very popular on 144.39 Mhz and 10.151 Mhz (checkout https://www.aprsdirect.com for a live map)
Digital Modes that don t fit in the above WSPR A beacon which reports what it hears onto the internet ROS A spread spectrum mode which is not allowed on HF in the USA WinLink A state oriented protocol which is a conglomeration of protocols which sends/receives E-Mail over radio
How to connect a PC to an HF Radio Two common problems when initially starting up in the HF digital modes Requires hooking a computer to a radio Distorted signal because of a ground loop Distorted signal because of incorrectly adjusted audio level(s)
How to connect a PC to an HF radio HF Radio Mic In Speaker Out PTT Audio Out Mic In PTT So far, Good! You can now receive digital signals! (PTT note: Can set your radio to VOX instead of keying it from the computer with a wire) Hot Neutral Ground
How to connect a PC to an HF radio HF Radio Mic In Speaker Out Audio Out Mic In Using VOX? Critical adjustments: VOX Gain, Anti- VOX and VOX Delay. It s MUCH better to allow the computer to control PTT than to use VOX. You can then set the PC to take T/R switching time into consideration. Hot Neutral Ground
How to connect a PC to an HF radio HF Radio Mic In Speaker Out PTT Audio Out Mic In PTT First time you key up your transmitter, this GROUND LOOP causes all kinds of problems: Mainly RFI and DISTORTED SIGNAL Hot Neutral Ground
How to connect a PC to an HF radio You need to BREAK this ground loop HERE HF Radio Mic In Speaker Out PTT Audio Out Mic In PTT Hot Neutral Ground
How to connect a PC to an HF radio With the audio lines, you can break the ground loop with audio transformers Mic In to Radio Audio Out from PC Speaker Out from Radio Mic In to PC
How to connect a PC to an HF radio With the PTT line, you can break the ground loop with an Opto Isolator PTT to Radio PTT out of PC
Using an RS-232 port to control PTT The RS-232 serial communication protocol has been a standard for many years (DB-25 or DB-9) Standard pin definitions for DTE or DCE, straight through or rolled TX -> RX RX <- TX DTR -> CTS (one standard on hand shaking ) CTS <- DTR (others exist using RTS, DSR, DCD and RTR) Wire voltage: +15 VDC to +3 VDC (Space or 0 ) -15 VDC to -3 VDC (Mark or 1 ) Frame format: Asynchronous ASCII Start bit, 7 or 8 bits of data, parity bit (odd or even), stop bit Speed measured in Bits per second Can use one of the OUT GOING HANDSHAKING signals to control the PTT on you radio (usually DTR or RTS)
Typical PC to Radio Interface
Proliferating as a standard serial interface Faster than RS-232 because it s a balanced, bidirectional transmission medium with power Outside pins are data Inside pins are power (5 VDC) Data connects first, then power USB interface
Typical USB connection to a Radio USB port in the radio takes care of the ground loop problem One wire between the PC and the Radio Much simpler! USB communication protocol is programmers choice Must ensure right software driver is loaded Frames of data sent to and from
Example: IC-7200 (Driver) From the Command table in the back of IC-7200 manual: To switch to transmit mode: 4. 0x1C 5. 0x01 To switch to receive mode: 4. 0x1C 5. 0x00
How to connect a PC to an HF radio The other problem is incorrectly adjusted audio level(s) Your PC has a volume OUT Your Radio has a Mic Gain IN First, how you adjust your Mic Gain when talking into a microphone
How to connect a PC to an HF radio Talking into a microphone is the initial stage in creating power out The louder you talk, the more out of your final amplifying stage You don t want to over drive your final amplifier stage, so this brings in Mic gain, Speech Processing, Compression, and Automatic Level Control (ALC) ALC *is* a form of Speech Processing All four of them affect the final wave form out of your transceiver For voice, by using any combination of these, you can enhance speech intelligibility by basically increasing your average power out (using SSB)
How to connect a PC to an HF radio HOWEVER, any kind of processing of a digital signal, ESPECIALLY with PSK, distorts the waveform; and the receiving end can no longer decode it Speech Processor OFF Compression OFF Absolutely NO indication of ALC on the meter Leaves three controls left to adjust Power out of Radio Mic Gain into Radio Audio out of PC
How to connect a PC to an HF radio Power out of Radio Most (if not all) HF digital modes are done with your radio in SSB mode The way SSB works is there s no power out unless there audio in If done correctly, you could leave this at max As long as you drive it with just enough audio to get the desired power out Most of the time, you want to turn this down, maybe some where between 25% to 35% in a 100 watt radio (a little less if you re a perfectionist) Mic Gain on Radio Most of the time, you can leave this setting at normal voice setting If your PC audio out won t go any lower, turn this down If your PC audio won t go any higher, turn this up Audio out of PC Adjust this until you get the desired power out If there s any indication of ALC, you re driving it too hard and your signal IS distorting
Familiar with the modes; got everything hooked up and adjusted You re ready to get on the air!
Which software to use? DIGTRX WSPR PC ALE Ham Radio Deluxe WinPSK Airlink Express DigiPan FDMDV WinDRM V4Protocol RMS Express MMTTY/MMSSTV TruTTY JVComm32 IZ8BLY Hellschreiber IZ8BLY MT63 DominoEXFEC WSJT JT65-HF Fldigi MixW Multi PSK (F6CTE) DANpsk YG-MM-PSK WinPSK QuikPSK WinWarbler PacTerm ChromaPIX CwSkimmer Throb2 5x3 MRP40-SDR CWGet Navtex YAND PSK2K Chip64 WinDRM RFSM8000 RCKrtty N1MM SIGMIRA AirLink Express HamScope Spectrum Lab Dire Wolf UISS NBF AGWTracker Winlink Express Etc Etc Etc Etc Etc Etc Etc Etc Etc Etc Etc Etc Etc
FLDIGI Screenshot Open source, GNU GPL, group software project available from Sourceforge.net Windows version, Linux version, Mac version
FLDIGI Screenshot
FLDIGI Screenshot
FLDIGI Screenshot
FLDIGI Screenshot
So there ya go! CW/Morse Code AM/FM/SSB RTTY AMTOR APRS SSTV PSK31 MT63 Hellschreiber PACTOR WinLink THROB MFSK16 Olivia Contestia JT6M Domino DominoEX THOR JT65 MSK144 WSPR ROS G-TOR CLOVER FT8