Well I finally had a chance to test my RTTY setup. I decided making a few contacts in the CQ WW WPX RTTY contest would be a good test of my RTTY hardware and software. For Hardware I’m using a Tigertronic’s SignaLink USB interfaced to my ICOM 756 Pro III. For software I am using N1MM with MTTY and 2Tone setup in the Digital Interface.
It took a little time to determine the best arrangement of all the N1MM windows on my monitor because the MTTY and 2Tone take up quite a bit of screen space. After I had the N1MM working with MTTY and 2Tone I downloaded a key file for the CQ WW WPX RTTY contest.
I also sent out a request for pointers to fellow hams in the Society of Midwest Contesters. Several experienced RTTY operators sent this rookie some key pointers. I’ve summarized some of them below:
- Watch your ALC level
Do not allow the ALC to activate because it can distort your RTTY signal; making it hard for others to copy. - De-rate your output power
RTTY has a 100% duty cycle when you are transmitting. This can stress transceiver and amplifier output stages. It is probably not a problem to operate a full power if you are doing Search and Pounce, but if you are going to try running a frequency it is best to reduce your power a bit unless you are certain your transceiver and amplifier can handle 100% duty cycle. It is advanced that you check your transceiver and amplifier manuals for their recommendations. In my case my setup should be able to handle the 100% duty cycle, but I chose to operate at 50% power just keep the stress low on everything in case I made some sort of rookier mistake. - Keep Your Macros Short
Don’t over do the length of macros in a contest. You can send your call twice when calling a station and send his call followed by the report twice and your call again for the exchange. You can always re-send the information if it is missed the first time. The default N1MM RTTY macros for the CQ WW WPX contest are reasonably short but can be tweaked a reduce them a little more. - Listen for a While Before You Jump Into the Contest
This was valuable input because when I first start tuning station during the contest it was a very confusing. After I had spent a half hour listening to other stations operating I had a good feel for properly tuning in stations and had a better feel for the flow of the exchanges. - Never Run Compression and don’t over drive the audio
Make sure that audio compression is turned OFF. Having it on will make it hard to make contacts. Also make sure your microphone gain is set just high enough to provide a clean audio signal. Keep the audio low enough that the ALC is NEVER triggered. - Add a space or CR at the start and end of your macros.
This helps to insure that your signal will be properly synchronized to the receiving end. - Make Sure Your Not Operating Upside Down
One of the most common transmit problems is transmitting inversely or up-side-down. RTTY is polarity sensitive. Transmitting inverted means you are sending a Mark when you should be sending a Space and vice versa. This can happen if you are using AFSK or FSK. With AFSK, it could mean you are using the wrong sideband. LSB is standard but USB can be used if you have the polarity correct. Yet, most stations who send inverted are using the wrong sideband. If you are set up to transmit in LSB, sending RTTY while in USB will result in your transmit being inverted.The above information was from AA5AU’s excellent article on operating RTTY which can be found here: http://www.aa5au.com/GettingStartedOnRtty.pdf
I would like to thank all of my fellow Society of Midwest Contesters for their helpful advice for this new RTTY operator.
After following through on the above advice I finally got on the air and made my first RTTY contacts last night during the CQ WW WPX contest. I was only on about two hours and did not set any records for rate, but I did make over 30 contacts. I plan to get on again to day and see if I can improve my skill. I’ll let everyone know how I ended up.
73,
Fred, KC9QQ
