1. RTTY Digital Mode Contesting and Prep for Field Day Use
N6MDV K6VHY
January 16, 2018

2. It has been suggested we do more digital modes in 2018
Why This Briefing?
It has been suggested we do more digital modes in 2018
Field Day 2018 Digital Modes RTTY is an option
Why?
Enables contacts on higher bands despite poor sunspot propagation
Lower SNR required than phone contacts
Develop additional skills for weak signal emergency communication
Easier to learn than CW for weak signal use
Possibly attract additional operators who don’t do CW or Phone

3. YES, we should be prepared to use those modes
Contents
Understand RTTY mode
What you will need to do RTTY on Field Day
What you need to set up your own RTTY capability
Not included…
Should we use RTTY, PSK31, FT8, MFSK or other digital mode
Answer is
YES, we should be prepared to use those modes

4. What is a Digital Data Mode
Means of sending text messages between computers via Ham radio communication
Using a windows or unix based computer:
Open a digital data mode program
Set some station information
Your name, call sign, maidenhead square code, and ITU zone
These are used by the program to send common information
Only your call sign is essential
Set up connection to the radio
Data connection
Can be an analog audio in and out to a sound card
Some radios have special RTTY digital data connection
Some means to activate the transmitter push to talk
May need to set up com ports/usb ports on the computer

5. RTTY Digital Data Mode RTTY Radio TeleTYpe
Two tones: 2295/2125 Hz
Transmission speed: 45 baud, 5 bit characters => 60 WPM
Bandwidth: 250Hz
Typically at xx.080 – xx.099 part of the band
Used to send text from one computer to another
via Ham radio transceiver
Messages of any length
originally based on mechanical teletype
No specific message format
just text transmit/receive
No built in error checking
With low SNR and QRM expect some character errors
Thus common to send critical information twice – like call sign
References:
aa5au.com/GettingStartedOnRtty.pdf
Known for contesting and faster
Photo courtesy of See that page for sounds also.

6. Example DigiPan for PSK31 Showing 1 strong signal on the waterfall
Macro buttons across the top
Multiple signal decode on right
Waterfall below

7. Example of MMTTY Screen Shot for RTTY
Macro buttons can usually be clicked with the mouse Or
Press a F1-9 function key

8. FLDIGI Another Popular SW Tool One software tool - decodes many modes: PSK, RTTY, MFSK, …
Many modes supported, but only one message decoded at a time

9. For Field Day Operation
A tent that with a RTTY/Digital station set up will have one or two computers
Logging computer
Digital modes computer (if not on the same machine as logging)
It will have an instruction sheet for how to do digital on that equipment
What software program to open (digipan, fldigi, other)
Setting the transmitter power
100W for voice SSB
Likely 20-30W for digital modes
Possibly how to set the specific windows computer sound level
Adjusting RF gain for good waterfall display
i.e., lower gain until waterfall shows just signals of interest
What mode to set the radio – typically SSB Upper Side Band USB
Some radios may have a special digital mode
What frequency to tune the transceiver to
Each digital mode has its own commonly used frequencies
RTTY 7.084, ,
Set the transceiver and computer as indicated

10. For Field Day Operation – Search and Pounce
Look to see who is calling CQ for field day and respond if not in log
Click on that person’s frequency on the waterfall
That tunes the software to their frequency and loads their call sign into the macro
Press the macro button for:
<call> de w6ha w6ha k
When they respond, press the macro to send our info:
<call> tu 3A LAX 3A LAX de w6ha
If there transmission was incomplete press the macro:
<call> agn? Agn? de w6ha k
Next move the transceiver frequency
Up or down across the indicated frequency range
E.g., for RTTY expect signals from
to but avoid
The transceiver bandwidth is likely 2.4Khz
So move the frequency up or down 2KHz to see if there are more stations using this mode
Meaning of messages:
DE = “this is”
K = “over, go ahead”
AGN = again abbreviation
fd = field day
tu = thank you
QSL = message received
<call> macro fill-in for their call sign

11. For Field Day Operation – Calling CQ - running
When have finished with others find an open frequency to call CQ
Look on the waterfall and click on an open frequency to call CQ
Tune the transceiver frequency up or down if needed
Try to stay close to where other digital operators are – so you will be found
Note that having your desired frequency in the middle of the displayed waterfall will likely provide a stronger cleaner signal
The radio’s internal filters often attenuate signals near the edge
Four macros when running during a contest
cq fd de w6ha k
<call> 3A LAX 3A LAX de w6ha k
<call> tu
<call> agn? Agn? de w6ha k
Press the macro for CQ
If someone responds press the macro for sending info
If not, press the CQ macro again
When they send their information back, press the TU macro and go back to calling CQ
If there information was not clear, press the Agn macro

12. Hints – Experience from other contests
Propagation is not a constant
You may see the other guy’s signal clearly, but he may not see yours
He may be running higher power or have better antenna
He may have more local QRM which is blocking your signal
Try a few times to respond, if it doesn’t work, move onto someone else
The other guy may respond to you but be off set in frequency
Could be his transceiver/computer are set up poorly
Go ahead and try to respond on your original frequency
After a successful CQ and information exchange…
Some people Jump in on your frequency to try to capture the other guy
I think that is poor form and do not suggest doing that yourself
I’d be inclined to go ahead and just do your CQ again
The jump in’s signal may be clobbered, but … you were on this frequency first
(Note, I see a lot of that on VHF/UHF FM contacts too)

13. Log the Contact Depending upon how the radio/computer are set up Or
The contact may be automatically logged when complete Or
You will need to type the call sign and information into the logging computer manually
Given how much time it takes to complete the transmission this is easily doable

14. Getting the Field Day Stations Set-up Each band station captain & transceiver owner need to set up for digital
Computer connected to radio via Terminal Node Controller (TNC)
Computer connection to sound card / keyboards / monitor / mouse
Load appropriate software on computer to decode sound & display waterfall
Set up Four macros for running
cq fd de w6ha k
<call> 3A LAX 3A LAX de w6ha k
<call> tu
<call> agn? Agn? de w6ha k
Set up Three macros when search and pounce
<call> de w6ha w6ha k
<call> tu 3A LAX 3A LAX de w6ha
Test equipment settings
Good signal out
Expected power level
Low distortion
Create instruction sheet

15. Equipment Setup Configure computer Determine optimum radio settings
Make or buy connection hardware between computer and radio
Audio interface
Remote radio control
Push to talk
Configure computer
Sound levels in and out
Turn off extraneous Windows beeps and sounds
Set appropriate software settings for each mode to be used (call signs, etc.)
Determine optimum radio settings
Max power for continuous operation (20% of max?)
Power level and sound card settings for
Expected output power
Low distortion
Appropriate ALC (small to none)
Ideally…
Test operation interference with 100W SSB on near by transceiver on same band

16. Example Digital Mode Hook Up
ICOM 7000 Radio RIGblaster TNC
Computer sound card & USB connection
CI-V and accessory connection on radio
Strong PSK31 signal
Decoding via Digipan software
Macro buttons across the top
Multiple signal decode on right
Waterfall below
ICOM 7000 multimode radio
CI-V
ACC
Computer Sound Card Connection &
USB Control Connection
RIGblaster TNC
Sound, control, CI-V link
CW and digital modes

17. Sunspot Values Continue to Decline Reduce propagation at 20M and above
Sunspots affection ionization
Ionosphere refract radio waves
Bends waves back to earth
Responsible for long range propagation
Declining propagation has reduced our contacts on higher frequencies
CW and digital modes need less SNR than phone
To maintain higher contacts need to
Use modes that need less SNR
CW would be best
Use lower frequency bands
80 and 40 meters
Smoothed Sunspot Numbers – Predict Propagation
Next few years will be lower than last few years
2017

18. Questions?
Thoughts?