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My SO2R setup
revised
on 13 May 2002
In
early 2000 I’ve decided to design and build an SO2R setup, which suits me the
best. After some experimenting I ended up with the following setup:
The
main SW I use for contesting is CT but I’ve also
got SD from Paul EI5DI
and in 2000 I bought Writelog, which I still
have to learn to master. I use CT most of the time because after so many years
I’ve really become used (or shall I say addicted?) to it and I managed to learn
most of its tricks and nuances. Besides, as a potential candidate for RSI I’d
like to minimize mouse usage and this keeps my ham directory Windows-free as
much as possible. Paul EI5DI gave me a copy of his SD software, which is the de
facto standard for RSGB’s popular IOTA contest and
applies very intuitive solutions for the unassisted SO contester. I really like
the way he implemented WAE in his SW.
However
DOS has its own limitations and a few years back I wanted to make my feet wet
with Writelog and the Windows-based software. The
high number of supported contests enables me to learn the software in part-time
or casual contesting and to hand out points on a casual manner more often.
Seeing the amount of traffic on the Writelog email
reflector and my experiences with Writelog so far
didn’t make me rely on it yet, but I’m confident within some years it will
develop to a reliable and robust software.
The
computer I use is a Compaq E500
Pentium III notebook
running at 660 MHz and having Windows 98SE software. It has only 1 built-in
COM-port, the other 2 are provided by an Argosy PCMCIA serial port extender, which hooks up
as COM5 and COM6.
When
I use CT I have to connect the logging PC to a second PC, which connects to the a local DX-cluster. It's done via a Xircom CE3 10/100 PCMCIA network adapter using K1TTT's
NETTSR . The second PC is connected to a TNC and a VHF radio.
Handling the frequent link breaks and cluster breakdowns is easier on the
separate PC and the second networked PC also keeps a copy of the log. With Writelog I can use the infrared port (COM3) of the notebook
to connect to the internet via a Sony-Ericsson
T68i the IR port and spare the second PC. This phone supports GPRS and enables me to connect to the Internet
for long time on a very cost-efficient manner (byte-based billing).
The
SO2R-box is designed and built by myself. It switches the headphones, the keyer, the microphone, the PTT. The box combines the keyer output with external paddle as well as the footswitch
with the PTT signal of the PC.
It
has a flip switch to activate the relay, which swaps the audio channels of the
two radios when one of them is switched to transmit. When the pileups on the run radio gets too intense I temporarily
disable the second radio.
The
SO2R box also does audio mixing: With a 3 position switch I can select any of
the 3 modes: active radio in both ears, one radio in
each ear and non-active radio in both ears. When I use the two VFO’s of the MP simultaneously, the switch is in the first
position and the MP takes care of mixing. When I use the second radio, the
second position is selected. The third (reverse) position is used when the S/N
in the mixed position is not enough to get a good copy on the second radio and
in this case I quickly turn the switch to get the call without changing the
active radio (cq does not have to be interrupted).
Separating
the PTT-controlled audio swap and the mixing function creates a tremendous
flexibility, which enables of selecting the right combination for any operating
situation.
Although
I'm not very active (or even keen) in SSB contesting the voice keyer connections of the soundcard have also been
implemented. The microphone is a Heil HC4 element mounted on flexible mike-boom
attached to a Sony MDR-V600. The microphone
is plugged in the notebook's mic input and the output
is fed to the radio via an isolation transformer.
Both
radios are from Yaesu: an FT1000MP and an FT990. The
FT1000MP is the best radio I could afford and I use it for casual DXing and contesting. The FT990 was selected as second
radio because:
·
this radio combines simplicity and performance the
best
·
the connectors are the same as on the MP
·
very well built and rugged
·
available
The
MP has all CW filters (Yaesu) including the one in
the 2nd VFO. This one will likely be replaced with an Inrad 400 Hz since
its steeper skirts would better fit S&P. For SSB only the 2.4k filters are
installed and I’m perfectly happy with them. The MP’s mod options are maxed
out. The PIN diodes have been upgraded, as well as the ALC and NB circuitries.
I took W2VJN’s idea of an intermittent
IF amplifier and use a broadband HP measurement preamplifier in
the MP. This preamp was designed to provide maximum linearity and has three
selectable amplification levels. These are set to 6, 8 and 10 dB. This provides
very h
The
FT990 has all filters installed.
The
main radio has one amplifier connected, while the
second radio has three via a 4-position Daiwa CS-401 switch (the 4th
connection has a dummy load).
The benefits of this solution
are:
·
the two TX branches are completely isolated
·
the tuning time is kept on minimal
·
the system reliability increases, since the outage
of one amplifier does not influence the system performance significantly
·
the switching is done at low power (beneficial for
the future automation)
·
4 manually tuned amplifier is significantly cheaper
than two auto-tuned ones (especially if home-made)
The Beverages (if built) are
connected to a coax switch, where the appropriate direction can be selected,
followed by a BC band filter and a two-position switch to select the Beverages
to one of the radios.
This
is the description of the SO2R setup how I have it implemented. It was first
tested in the IOTA 2000 (#2
in SO24/Mixed) and WAE CW
2000 (#3 in
SO) contests. In year 2001 my attempts in IOTA
(#1 in SO24/Non-IOTA/Mixed) and WAE CW (#1 in
SO) contests were more successful.
Major
plans for the future:
·
second amp (serial connected) for the run radio
·
automate the amplifier selection for both radios
·
design and build an radio controlled bandpass filters
SO
contesting is the secondary option for me since I always referred team
contesting. However there are some great contests like the Russian DX or the CQP offering lots
of opportunities to improve my skills while competing in the SO class. SO2R
seems to be the most competitive way of doing this that’s why I invested some
time and effort to put this setup together. If you have any idea how to improve
this setup further, please let me know. Your input would be gratefully
appreciated.
Click
here to get the schematics of the SO2R box
Click
here to get the schematics of the FT-990 CAT controller
This
setup has been developed based on ideas and/or publications of Tibi HA1DAE, Bill W4AN and Tree N6TR. TNX!!!
