Two (2) Radio 


To  be competative it is necessary to have as many functions as possible automatic. We heard about SO2R some years ago and started to plan for a future redesign of our station with automatic PAs, easy antenna switching etc.. 

There are basically three parts to co-ordinate: Antenna Switching, Rig Switching and Rig Keying. All three need to be easy to handle. The rig switching is done in two phases. The first one is to decide which tranceivers to use and when that is done arrange for keying of the radios as smoothly as possible. This includes automatic switching of keying, headphones, microphone and logging.

On the antenna switching page you can se how the antennas are switched through the RatPaks. From the RatPak the signal from the antenna goes to the power amplifiers as shown below.

 Rig Switching

SW1, 2 and 3 above decides which 2 of the 3 radios are to be used during the contest. It even allows you to choose which one to use as radio 1 or 2. To enable this 3 standard 3-way switches are built into a small box and used for each radio. The positions switchable are Radio1, Radio 2 or Standby. This is usually set up and tested a couple of days prior to a contest.

Radio 1 connects the RF output of the tranceiver direct to Hoscha 1, a motor driven coaxial switch. It also connects the PA relay circuit to PA1.

This way Radio 1 will be connected to RatPak Radio 1 through Band Pass Filter -1 and PA 1. Alla antenna switching is done by RatPak Radio 1.

Radio 2 connects the RF output of the tranceiver through a coaxial relay to Hoscha 2. It also connects the PA relay circuit to PA2.

This way Radio 2 will be connected to RatPak Radio 2 through Band Pass Filter -2 and PA 2. All antenna switching is done by RatPak Radio 2.

The Standby position leaves this tranceiver unconnected.  

The Band Decoders are delivered by Top Ten,, and serves the purpose of automatic switching of the BPFs, delivered by Array Solutions -,  as the bands are changed. The switching of which rig to use is done manually prior to the contest. The EZMaster an all mode - all in one PC interface,, which takes care of the keying and switching of the radios is described below. PA1 is switched directly by Radio 1.
I might re-build the switching of the BPFs and use the output from the EZMaster instead of the Band Decoders at a later stage.

Two VFD SWR meters are connected after the PAs and they monitor the SWR as well as show the output power. The relay control from the X-mitter is routed through the SWR watch of the VFD. If a SWR above 2:1 occurs the keying of the PA is disrupted immediately. The SWR watch can be set for various values and the PU-unit is located near the PA and the actual meter close to the rig.. The VFDs are obtained from Array Solutions.

This way the PAs are protected should the wrong antenna be connected or a malfunction of an antenna occur.




Above the antenna switches on the right is the rig switch and the band decoders and the IC 775 is choosen as Radio 1 while the IC 756 PRO is Radio 2 and IC 781 is on standby. A total of 24 antennas can be switched. If 2 more SixPacks are added another 12 antennas can be connected.


The pick up units of the VFD is fitted with the Ecoflex 1/2" cables. The smaller cables from the top  of the pick up units are the feeders to the VFD controls at the rigs.


 Rig Keying


The EZMaster resting on top of the IC-7800


 WriteLog,, is used as contest logging program. Above is the connections between the rig, the keyer and the computer shown The program works very well on CW, RTTY and SSB as a SO2R program.  All is running on Windows XP Pro.

To enable full use of the program I used a W5XD Multi+ keyer from 2000 to 2004 - the connection diagram can be found here.

When I changed computer in late 2004 I got an EZMaster, This device controls all that the W5XD Multikeyer does and a lot more including DX4Win as well as running 2R without the computer turned on. 

The headphones as well as the keying has been flawless so far and really speeds up operation even more than the old keyer. Most of the commands have been moved to the key pad with the aid of the Key Control program. This includes split ear-phones, key board focus, x-mitter focus and S&P logging. Automatic CQ is still on the F11 key. All other functions are left on the old control positions. The Sound Board is used together with MMTTY for RTTY operation in WriteLog. No Sound Board is needed for SSB since the EZMaster includes a DVK.

DX4WIN is  used for logging all casual QSOs. In the 6.03 version the EZMaster keys the CW, Data and SSB Modes in 2 radio operation. This makes it easy to keep track of DX-peditions operating on two bands by using split headset.