N4TB SO2R INTERFACE
The N4TB SO2R Controller is used to route commands from the N1MM Computer Logging program to two radios for Single Operator Two Radio contest operation.
SO2R Operation allows the operator to work on two different bands at the same time. Typically you would be running station on one band and looking for multipliers on the second radio. The SO2R controller prevents both radios from being keyed at the same time insuring you will remain in the Single Operator category.
The N1MM Contest software also has some neat functions like “dualling CQ's” where you can call CQ on one band and while you are listening for a reply you are calling CQ on the second radio. When a station returns your call you type in the call and work the station as you normally would any contest QSO. The software automatically logs in on the correct band. This is very useful to catch band openings on 10 or 15 meters during the low part of the sun spot cycle.
The SO2R controller can be used for CW, SSB or RTTY contesting. Audio from the sound card and PTT commands are routed to the selected radio. For CW operation the output of the keyer is routed to the selected radio in addition to the CW generated by the contest logging program.
For non contest operating the Manual mode is selected and the Radio 1/Radio 2 switch selects the radio you want to use. The audio, PTT and Keyer outputs are routed to the selected radio.
The circuit is not new and will not be reproduced here. It is basically the KK1L SO2R unit. The schematic can be found at the following site: http://www.ok1rr.com/view.php?cisloclanku=2004122506
Block diagram of the SO2R Controller and Radio/Computer interface
Front Panel of the SO2R Box:
I did not include the audio switching relays in the KK1L design because I want the switch to switch the audio located near the keyboard. I used a surplus lever switch. In the left position the audio from the left radio is in both ears. In the center position audio from the left radio is in my left ear and audio from the right radio is in my right ear. In the right position both ears receive audio from the right radio. This allows complete flexibility with the received audio. During a good run I can have both ears listening to the run frequency. During slower times I can be working stations on one radio and listening for multipliers on another band in the other ear.
SO2R Controller rear panel:
Below is the audio switching box which is located next to the computer keyboard and remote tuning knob. Audio can be switched independently of the SO2R box. The Koss QZ Pro Noise Canceling headphones are used most of the time. The noise canceling feature not only eliminates any background noise but also the rumble from the fan in the Ten Tec Titan Amplifier which can become quite fatiguing after several hours in front of the radios.
