Here are a few photos of my contest station. It's always a work in progress.
Note: The first three sections were written before completion of the big tower project. The remaining sections show
further evolution inside the shack.
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The following was written before completion of the big tower project:
In anticipation of the big tower project (see elsewhere on this site), I decided to rewire the shack.
The new tower will add a whole new level of complexity: three TIC rings, two more SteppIRs, a MicroHam
Stack Match with Main and Aux ports, and probably an 80m vee.
The SO2R switching system for the crankup, AB-577s, 4-square, 160/80 vee, and 80m delta loop is maxed out.
So the new tower will need its own SO2R switching system, which will be capable of supporting 6 antennas (total capacity of
12 antennas between the two systems.) The combined system will need the capability to switch both radios between two
independent 6-antenna banks.
The SteppIRs are especially tricky because they each have a controller to do the tuning. The switching system
has to be smart enough to know which radio has which SteppIR(s) and to what frequency they need to be tuned. I previously
built a microcontroller-based inteface to handle my one SteppIR antenna. That project is described elsewhere on this site
(see links to the left.)
In the new system the 3-stack makes things more complicated. Switching will require interacting with the
computer logging program (or tapping into its protocol with the radio), communicating with the Stack Match, and communicating
with the SteppIR controllers. I plan to write a PC-based switchings system that uses microcontroller-based switch boxes for
each radio. When it's done, I'll post details on this site.
Another goal of this project was to relocate the autotune amps away from the shack to reduce heat and noise.
This may look like a rat's nest of wires, but it's actually relatively neat, and a whole lot better than
before. Each cable has (or will be) labeled and color coded. The cables have been dressed so it's possible to pull the desk
out to make changes.
Eight more cables will be added to support the new tower. More cables will be added when I complete the
PC-based switching system.
WC1M SO2R station
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Another goal of the project was to get the second monitor closer to the first monitor. I had it way off
to one side before. Finally, the last goal was to get the piles of boxes off the radios to improve ventillation, gain more
space for boxes, improve ergonomics, and make it look nicer. Shelving did the trick.
The shelf design is from a commercial shelving product I used to build our entertainment system. It consists
of pre-drilled maple shelves supported by thread rods and nuts. The shelves, rubber feet, nuts, washers and flat top cap screws
I used for the shack were leftover from the original shelving project. I just had to cut up a few pieces of thread
rod I got at Home Depot.
Amps, filters, stubs, switches
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I relocated the Alpha 87A and Acom 2000A to the basement directly below the shack. This is also directly
below the point where all the RF and control cables enter the house. The beauty of this is elimination from the shack
of massive heat from both amps and some fan noise (mostly from the 87A.)
The Acom is easy to setup for remote operation. It has a separate control head with a complete operating
panel. The cable is 10 feet long, more than enough. The 87A has to be operated from the AlphaRemote software via RS-232. It's
OK, but not as nice to work with as the Acom. I built a remote LED display for power and grid current to be displayed in the
shack, which helps. Despite the somewhat awkward interface, I still prefer to use the Alpha for running.
The gold boxes next to the amps contain switchable W3QNQ filters for 6 bands. It's an older design sold
by Array Solutions, but now discontinued. To the right of the Acom are coils of stubs for the two radios. These are switched
in combination through Top-Ten relay switches. A handful of A/B switches are used to route signals from the various tower
locations, route one of the SO2R feeds to a 6m radio (the SteppIRs have 6m capability), etc. The main SO2R switching
is done at the crankup tower. A second SO2R system will be added for the new tower, requiring the capability to switch
between two complete SO2R banks.
Old Antenna Switching Interface
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This is the interface I used for automatic SO2R antenna switching for
about 10 years. It was connected to band decoders on each radio, and used a combination of diode logic, IC logic and relays
to route the various antennas to the two radios and provide visual indication of which antenna was being used
by which radio.
As you can see from the front and rear panel photos, the interface had no room left to add a second
independent SO2R switch bank. But that wasn't the real problem: with some drilling and cutting, I could have upgraded
to a larger box.
The real problem is shown in the third photo: the logic for switching the antennas in my station had become
so complex that the inside of the box was like a plate of spaghetti. The logic had to be changed almost every time I added,
changed or deleted an antenna, and the wiring had gotten so tangled up that it took hours to trace out what needed to be changed.
There was no way I could add a second SO2R bank to this mess. I was forced to redesign the station switching
system. Instead of continuing to use band decoders and hardware, I decided to convert as much of the logic as possible to
Windows-based software.
AntennaMaster
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Here are some screen shots of AntennaMaster. The top window is used to launch
antenna switching windows for each radio. The middle window is used to set the many configuration options.
The bottom window is the antenna switching window for a radio. The heading bar shows that the K3 is on 21.320 KHz. AntennaMaster picks that frequency up from Writelog (or N1MM or
WinTest, or OmniRig/Skimmer) and uses it to determine the antennas available for that band: the SteppIR stack, the Aux Stack
port (can have one of the antennas from the stack), the 20m monobander, the C3E and a dummy load. Automatic selection of antennas
by band can be overidden by turning off Auto or clicking on one of the yellow band buttons.
There are also buttons for switching in Stubs and Filters, reversing the Beverage, stacking (paralleling)
antennas, and switching the secondary bank of transmit antennas to be available as RX-only antennas. The TX INH button is
for testing and is only available in my copy :-) The set of red indicators simulate LEDs to show which output ports on the
Hamation Relay Driver are active (see below.)
Note that in addition to autotuning the SteppIR stack, AntennaMaster autotunes Acom 2000A amplifiers.
At some point I'll write a more extensive description of AntennaMaster and post it elsewhere on this site.
Hamation Relay Drivers
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The key to convering from a hardware-based antenna switching and tuning
system to a software-based system was finding a way to interface the PC to the many relays used for switching antennas and
other devices in my station.
I considered designing and building my own interface based on RS-232 communication, with which I'm pretty
familiar. I planned on using a PIC microprocessor and high-output shift registers to activate the relays. For someone with
my fairly limited electronics background, there would be a signifiant learning curve and it would take a fair amount of time
to implement.
Luckily, I found an off-the-shelf solution: the Hamation Relay Driver (www.hamation.com). This unit allows a software program to send commands over Ethernet for switching up to 32 relays. The Ethernet solution
conserved COM ports on my computer, which were already in short suppy (I use 10.)
The two brown boxes at the bottom of the photo are Hamation Relay Drivers. With two separate SO2R banks,
plus Stubs, Filters, etc. I needed two of them, for a total capacity of 64 relays. As it is, I'm nearly maxed out!
Relay Interface Board
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Above the relay drivers is a set of eight interface boards. I have a mix of relay-driven equipment in the
station, some of which requires +12VDC to activate, and some of which requires GND to activate. Also I didn't like the idea
of intefacting the MOSFET output drivers in the Hamation units directly to antenna relays outside -- there was too great a
change of a lightning surge or accidental short. So, I designed a simple PC board that uses the relay driver outputs to drive
miniature relays. Jumpers are used to set the output polarty of each relay (+12VDC or GND) and to configure a bidirectional
LED to indicate the status of each relay (red=+12VDC, green=GND, off=open.)
The photo shows the test configuration I setup while writing AntennaMaster. I later moved the relay drivers
and interface board to the equipment closet in the basement (see below.)
Lightning Patch Panel
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In August of 2007, shortly after completing the Big Tower Project, a massive
thunderstorm struck our area. It was the largest I've seen in 36 years of living in West Central NH. Despite my extensive
ground system and network of lightning arrestors and suppressors, over $10,000 worth of damage was done to the station equipment
and various other devices in the house. Fortunately, our homeowner's insurance covered almost all of the replacement and repair
cost.
At some point I'll write a more detailed description about what happened
and why, and modifications I've made to the suppressor system. For now, here's a picture of the most important thing
I did to prevent a recurrence: I added a quick-disconnect panel so I can interrup every cable going into the shack in one
place, including coax, switching control lines, SteppIR control lines, rotor control lines, AC, satellite TV and
telephone. A similar panel is located behind the entertainment center in the living room.
It took quite a bit of time to design and build this panel, but it was well worth it. I feel a lot better
when everything in the shack is disconnected from the outside world.
(Note the Hamation Relay Drivers and interface boards have been moved to the basement,)
Equipment Closet
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Late in 2007, we decided to clean out our basement, which over the past
15 years had become a dumping ground for things we didn't need, put in some nice wall-to-wall carpet, add some nice doors,
etc. The basement wiring and amplifier station didn't fit in too well with the new look, so we had a closet built around the
station gear. Now it looks nice and my 5-year old son can't get to the cables!
Current Station Configuration
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Here's what the station looks like as of November 8, 2008.
Controllers for the two SO2R banks are above the rigs, on the left and right,
respectively. This corresponds to the physical location of the antenna banks. The older bank of antennas is to the left of
the shack and the new bank on the big tower is to the right. This makes it easy to remember where to look for a particular
controller.
See the close-ups below for information about the equipment on each
side.
In the center, you can see a Yaesu FT-857 I got mostly for 6m, before acquiring
the K3. Now I use it for 2m FM (rarely) and for listening to the local FM broadcast stations. It's wired into the switching
system, so it can use the antennas for the radio on the right (currently an Orion), with a click of the mouse in AntennaMaster
(see below.) Also in the center is a switch box for routing audio from the two radios to the computer (mostly for RTTY, which
I rarely do). The Schurr paddle in the middle was my main key for a long time. The Begali Sculpture (a total indulgence that
will hopefully hold its value), next to the keyboard, is the current key. Under the right side of the monitor is
the remote control unit for the Acom 2000A amp in the basement (see photos above and below.)
The old monitors have been replaced with more modern wide-screen models.
K3 and Left Bank Controllers
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A K3 has replaced the Orion as the main run radio. Although the Orion has
an excellent receiver, I feel the K3 receiver is significantly better. In addition, the K3 has many other superior features,
and the ergonomics are better. The Orion has been moved to the right side, where it's now the main S&P radio, replacing
the FT-1000D (see below.)
To the left of the K3 is an LP-PAN, used to tap into the K3 IF for applications
such as PowerSDR-IF, CW Skimmer, etc. I sometimes use PowerSDR-IF as a pandaptor and as an excellent AM receiver. I used CW
Skimmer in the 2008 IARU CW contest, where it was allowed in the Single Operator category. I probably won't use it again for
a serious CW contest effort.
On top of the LP-PAN is a two-way RX antenna switch. The NE/SW dual DXE
dual beverage is one option, and the left-bank of transmit antennas is the other option (the bank is switched to the RX switch
through my AntennaMaster program.) In either case, the output is split via a T-connector between the K3's RX ANT and AUX RF
ports. This provides flexibility in directing the receive antenna to the Main and/or Sub receiver. The setup works well for
typical RX antenna applications, like using a beverage on the low bands, and also for Diversity reception, a unique feature
of the K3. Using the low-band transmit antennas with the beverage in Diversity mode can be very effective for digging out
weak signals. The same holds true for using the 40m 4-square as a Diversity RX antenna with my 2-el 40m beam.
Above the K3, from left-to-right and top-to-bottom: a homebrew low-voltage
controller for the US Tower 72' tubular rotating crakup, an EMU-202 USB soundcard for use with LP-PAN, the 40m 4-square controller,
an Elecraft XG-2 signal generator, meter to monitor 40m 4-square dumped power, DCU-1 controller for 4-el 20m monobander on
the UST crankup; 5-el 15m monobander on AB-577; C3E on AB-577, switch box to route one of those rotors to DCU-1, outboard
LED display for Alpha 87A amp (output power and grid current), Nye RF Power Monitor, and mic for the FT-857.
Orion and Right Bank Controllers
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As mentioned above, the Orion has been moved to the S&P radio position,
replacing the FT-1000D. Although I was fond of the old 1000D, the Orion receiver is far superior.
Above the Orion, from left-to-right, top-to-bottom: Top SteppIR controller, Nye RF Power Monitor, Green
Heron rotor controller for Orion rotor turning the Cal-AV 2D-40A @110', Middle SteppIR controller, LP-100A Vector RF Wattmeter
(monitors K3/87A), MicroHam StackMax with InfoPanel, Bottom SteppIR controller, N8LP SteppIR Tuning Relays (currently used
only for audio and visual indication of tuning -- working on an AntennaMaster feature to disable transmit while SteppIRs are
tuning), Green Heron rotor controllers for Top/Middle/Bottom TIC rings turning 4-el SteppIRs.
The SteppIR controllers are automatically tuned by my AntennaMaster software via RS-232. The StackMax is
monitored by AntennaMaster to determine which radio has which SteppIR(s). The RS-232 lines can be moved to the Green Heron
rotor controllers for testing. Using Green Heron's server software, I can take my notebook computer to the tower, where I
have a CAT5e Ethernet connection to the shack network, and use it to turn the rotors while I watch up close.
Main Monitor
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The main monitor is showing what I see during a contest: Writelog and
AntennaMaster. This shot shows only the abbreviated AntennMaster window for the Orion. Normally, I would display the abbreviated
AntennaMaster window for the K3 to the left of the window for the Orion. But I've moved the K3 window to the second monitor
to show you what the expanded AntennaMaster window looks like (see next photo.)
Second Monitor
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I run a variety of applications on the second monitor. On the top left,
VOAProp is a very useful application for seeing where bands may be open. On the top right is AlphaRemote, the remote
control software supplied with the Alpha 87A amp. Below that is the mult window from Writelog.
On the bottom right is the AntennaMaster main window. In
the center is the K3 AntennaMaster window. Normally, I collapse this window to show only the top row of antenna buttons and
put it on the main monitor below Writelog (see previous picture.)
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