Welcome to my DEF CON Ham Radio Village talk on my rover van.
My name is Pete Koback and my call sign is Kilo Zero. Bravo Alpha Kilo.
I want to say first that I'm really happy to be here at DEF CON, even virtually,
because I spent 17 years in web application security,
and although I attended quite a few security conferences in that time,
I never did get to DEF CON, so I'm glad I'm here now, and I'm glad you're here with me.
I first got licensed relatively recently,
after waiting 40 years when I first had an interest in ham radio as a teenager,
but didn't have money, and then didn't have time with a family and career.
And I had been fascinated by reading about the activity of roving,
either activating counties and state QSO parties, or grids and VHF contests.
And my first effort was in 2014 in the Pennsylvania QSO party, my home state,
and I won the category, mostly because there wasn't much competition in the category,
but still, I had a lot of fun doing it, and it wasn't bad to win either.
So, a kind of a career was started there in roving and contests.
When I first started, I used the family minivan,
and on the left here you can see four low VHF bands on a rotator in the back of the van.
And here is the HF antenna I started with, which was an elevated ground plane.
I since replaced that with a screwdriver antenna,
because although this antenna works well, it takes too long to set up.
Although I had fun operating the family minivan,
it was a pain in the neck to have to tear it down each time after I'm done,
and then build it out the next time.
Also, I couldn't drill holes, so I was thinking,
gee, it sure would be nice to have a dedicated vehicle.
The ultimate such vehicle would be electronic news gathering.
It would have a pneumatic mask, power, and racks,
and it would be a perfect base for a VHF ham rover.
I looked every so often, not really very seriously.
They always seemed to be offered far away,
and I wasn't really looking in any kind of systematic way.
However, in the summer of 2016, my buddy Rob found the TV van that was only two hours away.
So we went up there.
Since he's a gearhead, he gave it a mechanical thumbs up.
We saw that the generated pneumatic mask worked,
and after going away for a couple weeks and thinking about it,
I purchased it and paid for it, in effect, by delaying my retirement.
Here's a list of the features in the van.
I won't go through these step-by-step, but a pneumatic mask, power generators,
a powerful engine because it's quite a heavy vehicle,
and a flat roof with a ladder.
That was meant for TV reporting.
That would make it easier to climb up there and install antennas that I needed.
Here's what the van looked like when it was on offer at the dealer.
You can see some pretty heavy antennas on the roof of the van
that would have to be removed for my own antennas to be installed.
And here's a look at the interior production area,
where you can see that they removed all their expensive equipment and left the cables behind.
I bought the van at the end of October of 2016,
registered it, replaced the batteries,
and something I didn't even think about was garaging it.
So I didn't have a garage tall enough for it,
so I threw a tarp over it, which didn't work all that well,
then certainly didn't look very good,
and didn't have any build progress that winter.
In the spring, I took down the antennas I could by disassembling it
and walking the antennas down the ladder,
but the front antenna for satellite was too heavy,
and another buddy of mine from a VHF club, Phil K3TOF,
helped me by taking it off with a pulley at his pole barn.
Ironically, the first radio that I had installed in the van was not a ham radio,
but was a combination radio, backup camera, and navigation device.
Also, I had a Bluetooth player for long drives,
which is not a small thing when you're doing a long drive by yourself.
One of my first bad surprises was in the spring after I bought it,
I found that the generator, the motor part started right up,
which is good, but there was no voltage I could find.
I was surprised by this, because we saw the meters on at the dealer,
and it ran the pneumatic mass, at least I thought so.
I finally discovered that the AC we saw at the dealer had come from the van engine,
and I'm kind of embarrassed to admit that I didn't even know it had that feature.
I guess it's good to have the feature, but bad that I didn't know about it.
So, the generator part of that gasoline gen set had to be rebuilt expensively, and it took quite a while.
At the same time, 2017 is my first year of retirement,
and I did a lot of operating because I had the freedom to do so,
and because I was operating, I didn't make much progress on the van.
Finally, at near the end of the year, I deconstructed the minivan Rover
in the hopes that I would have more time, or force myself at least to have more time,
to outfit the TV van.
The next winter, I found a garage for it that was relatively new,
and the problem was it was one hour drive each way,
but at least I had a place to keep it over the winter,
and could do some work inside during the winter months.
The first big project in the winter was to remove the cables that were left behind.
I did so by not cutting them, but removing them and putting them aside,
or wrapping them up here on the side and cleaning the whole van,
which had not seen much cleaning since it was built in 2001.
The first thing I ever built for the van was a shore power connection.
Here's a little cable with an adapter that was kind of unusual.
You would have thought it would be standard in the RV world.
It was not, so it was hard to find and surprisingly expensive,
but at least my first build was successful.
The first of many things I built for the van down the years.
Now in 2018, unfortunately, most progress halted
because of a major series of basement floods we had at home.
It took out my home station and forced me to spend a lot of time
fixing it up or preparing it to be fixed up and renewed again.
So very little progress was made on the TV van because of that.
2019, though, had quite a bit of progress in the van.
I won't go through this entire list, but one of the big features of that year
was operating in the Canadian National Parks on the Air program,
installing radios, the power systems I used during that operation,
and a microwave power shelf.
So in contrast to the previous year, I did make a lot of progress two years ago.
In this calendar year, though, the major theme,
including the very end of last year,
was mechanical problems with the engine,
in particular the serpentine belt in the engine.
So the van was out of commission for many weeks in two different events,
not allowing me to make progress in building or operating the van.
In between the events, I did go on what I called
Corona Roads to local parks and operated from parks,
since I could still be isolated from other people while operating inside the van.
And right at the moment, the station is down for upgrades,
but that's a good thing, and it'll be back on the air shortly.
Now I'd like to talk about power, which was most of my effort
of building the interior of the van so far.
So I started with surveying the
capabilities of the van as is. The van has three
5 kilowatt AC sources, a generator set that I talked about,
an origin that was power from the vehicle,
and the plug-in shore power. So the problem
with the generator set was that it was very loud
inside. Audio-wise, it was really loud and shaky,
and not only was it loud inside the van, if I was
anywhere where the public would be, like a park,
it would be really distracting and not a nice thing to subject
other people to. The origin is relatively quiet
because just the van engine is running, but RF-wise, it was
horribly, horribly noisy, so that was out.
Lastly, there's RF noise just from the van engine
even when the origin system wasn't on, so my overall conclusion
was that I needed batteries for doing weak signal radio. I couldn't
rely on any of the internal generating sources.
The DC power system included two
batteries wired in parallel
permanently, which was a shame because
it would have been nice if the auxiliary battery was switched in.
I noticed there was no protection for high current circuits, which
made some additions to the DC power system dangerous.
I did have available 320 amp
radio DC circuits, but that's really not enough
power to even have barefoot power, no less
amplifiers. The battery charger that they left behind that I
started trying to use was actually burned out, which is probably why they left it behind.
So my overall conclusion was that I also
needed a separate radio station DC power system. I couldn't take
much advantage of anything that was existing in the van for DC power.
So what were my power assumptions when I started?
I was going to use my
home station Flex 5000 SDR.
The thing about that series of Flex radios was that
the radio processing was done on a PC via
firewire. The laptop was out of the question because of
using less reliable connections. So I needed to use a rock-mounted
desktop class PC, and that meant
I needed AC power for that PC. So going through
this line of assumptions led me to the conclusion that the station
would be based on AC power and DC would come from conventional
power supplies just like you'd use at home. And I'd
use batteries and an inverter for AC power because, as I
said before, I couldn't rely on the internal generators.
I decided that the AC power
would be up to 3 kilowatts so I could eventually accommodate the limit
amplifiers. And I wanted to make that decision once because it was heavy and hard to wire.
So I wanted to make sure I was future-proof even if I wasn't
going out with the limit amplifiers at first.
I would use direct battery power for the station DC
and I would use dual batteries for flexibility.
I could use the AC inverter
from one battery with the DC supply from another or maybe I could use one while
charging the other. I knew I would get good flexibility by having
two batteries. And lastly, I would need a charger maintainer for the
van batteries because the van would be in storage a lot
of the time and, like any vehicle, you need to maintain those lead-acid batteries.
Here's a
diagram of the overall power design context.
I first have to apologize because my
writing is so terrible. It seems like I learned to print and to draw
and then just stopped learning when I was at the age of 7.
So my drawings are awful and I don't have the time or patience to draw them in
a drawing program.
I hope you'll forgive me for these awful looking diagrams.
The overall context diagram includes
the old systems and the new systems. It includes both AC and DC.
And we're going to be going over many of these systems one at a time.
We went over the requirements, the context
diagram, and now we'll spend some time
on the implementation of those power systems.
Here's a picture of the key power components.
Here's that 3 kW inverter, charger, switch that I mentioned.
And here are two 200 Ah each.
Nominally 12 volt batteries.
These are 115 pounds each, so they are quite beefy.
Batteries actually deliver
an enormous amount of current.
Even just mounting the batteries required skills I didn't have before.
And that's one theme I wanted to bring out.
This entire project taught me quite a few really basic
mechanical real world skills I didn't have before.
Many people learn how to do things like a cut with a table saw when they're in their teenage years.
I didn't know any of that.
I had a virtual life on computers almost my entire career.
This was new to me.
And it was scary making my first cut on my first table saw.
So this is just one
especially dangerous example of things that I learned to do
just for the sake of the van.
So using that table saw and my newfound skills, I cut boards to constrain
those 115 pound batteries horizontally.
I used straps that you can just barely see here and here
to constrain the batteries vertically.
And here is a binding post to tie together all the negative side of the system.
So let me describe the A.C. part of the
system build.
Over here is the native A.C. system that was already in the
van and here is my new A.C. system.
The inverter charger
switch can supply
current to the A.C.
system in a back feed arrangement
and the power is supplied from the shore power
into the new A.C. system, into that big blue box I showed.
I would have 15 amp outlets
that are existing in the racks
and I would also build 25 amp outlets that were brand new.
And to run off of battery power
there would also be a very large 200 amp capacity
connection to the battery system.
So here is a diagram of the A.C. power circuit. What I did was to
connect into, rather than replace, I connected into
existing A.C. circuits in the van.
So here is a supply that I pulled off
of these original circuits that
are no longer used in the van to supply A.C.
power into the inverter, say from shore power
when I'm, for instance, charging the batteries.
And then the output of the inverter would go through
a new 30 amp circuit breaker and then branch
off into two of the racks for an existing
15 amp circuit and another existing 15 amp circuit
for the other two racks. And lastly, I
installed two new sockets for higher current A.C.
supply. And here is what the
new A.C. power panel looked like.
This is the main circuit breaker. Here are the two 15
amp circuit breakers in a double arrangement.
And here are two higher current sockets for
someday for legal limit amplifiers that require
this amount of A.C. current. Here are the
two multi-wired cables going back to the electrical panel.
We'll take a look at the electrical panel shortly.
And here's that same system mounted onto the back of
rack number one. Now these two
multi-wired cables go to the A.C. distribution in the
back driver's side of the van.
Which looks like this.
This is a before picture and this is an after picture. And you can see those same two
multi-wired cables coming up into the panel on this side and being
wired into existing circuits. And you can see that I was lucky that this
terminal block had a lot of unused circuits. So that made
it a lot easier than it would otherwise have been to wire in my own
connections into the A.C. panel.
Now I added some labels to the native power panel to
tell me how the switches should be laid out, at least in
ordinary operating conditions. So this is the
input power into that
big blue box, the inverter charger switch. And these, even though they're
off in this picture, these would normally always be on. And in
contrast, I am connecting the output of that
inverter to these two circuits. So normally these would be off
because I already have current on them. But this does allow me
to do a back feed into the rest of the A.C. system if I had
some emergency that would require me to supply A.C. to other
parts of the van besides the rack circuits that were intended.
Now here's both D.C. power panels, and we'll be going into
this in detail. This is a picture at the bottom of rack number two,
in other words, the middle of the three racks.
So I'm first going to be talking about the battery system that's really at the core of
the entire system that supplies power to both the A.C. system
that we just talked about and to the station power.
The battery circuit is relatively simple
electrically, but it was hard to build because of the size of the
cables that I had to deal with. So you can see that here are the two
batteries I showed in the picture earlier. Each battery has
two fuses mounted right on the terminal, which I didn't even know existed
before I started this project. So that's a nice safety
feature to have a fuse right on the terminal of the battery.
200 amp coming off of each battery for the
inverter charger to give it enough power to supply
three kilowatts of A.C. power. And then the 80 amp circuit coming
off of each battery goes to this switch and then to
the station power system here. Here's more of a
close-up of the battery switch panel.
So here are the two switches that I showed in that circuit diagram.
They can select either battery or both together or
both off. These two
green panel
meters alternately show voltage and current, but only
when their respective switch is on. And this always
shows voltage to the batteries no matter the switch position.
All these meters are only on when the meter switch is on.
And that allows me to not drain the battery unnecessarily when, say,
the van is in storage. Here's the back
of that same panel. You can see how large some of these
cables are. This is a quad-zero gauge wire.
It's very big and very expensive and really hard to work with, as you might
imagine. These are two double-zero cables that go to each
battery. And this is the 200 amp side of the circuit. And, of course,
this is the 80 amp side of the circuit with 4-gauge
wire being used for that wiring. Here's a
top view of the installed batteries with the
two fuses that I mentioned earlier here
connecting to the panel. And you can just barely see down here
the common connection point for all the negative leads. In between the two
batteries is a, which I'll be talking about shortly, an
80 amp boost regulator. It just happened to fit very well between the batteries
just by chance. So it's a nice spot for it. It's nice and cozy
in there without having to take up, say, a rack space. So that
was a lucky thing. Now let's talk about
the two-way charging system.
And here are the controls for that
two-way charging system. On the right is another
instance of that volt-amp meter. In this case, this is
showing the voltage and current from or to
the van battery system.
This is a meter switch, like I talked before, so I can turn this meter off when
the van is in storage. And here's a double-throw switch that allows
me to put current in either direction into the batteries
from or to the native
vehicle battery. So in the up position,
I can charge the station from the van alternator while the van
is in operation. In the down position, I can charge the
van batteries
when the van is stationary. I can charge the van batteries
while AC power is supplied.
Here's a circuit of that two-way charging system.
So the key part of the system is these two 65-amp
solenoids that connect the station battery
to the vehicle battery
when necessary. These are in turn energized by
this smaller capacity relay that fires six seconds
after the ignition signal is set. I have
this six-second delay in order to allow the van engine
to stabilize before I connect the large station batteries
to the van batteries. And down here is
something called a battery tender, or in other words, a battery maintainer
charger. And this can be switched in
or out by that double-throw
toggle switch that I showed in the panel before. And this supplies current into
the van DC system
with the solenoids off in that position so I can
charge into the van DC system.
Next I'm going to talk about the station power system.
And that is fed from the battery system with
up to 80 amps and
then moves as a regulated 80 amps into station equipment
or into the computer. And here's the station
power control panel on the left-hand side of that
same rack panel I showed before. One controls
the input into the
80 amp booster, and the other controls whether
I am supplying power to HF components, VHF components, or
both. The station battery
switch output, that 80 amp switch
I showed in the lower panel, first goes to a MIDI
fuse block to supply current to the
unregulated battery output binding post.
It supplies current in from the
two-way charging system I showed earlier. And the main circuit is
an 80 amp fuse that protects the rest of the system for all the other
station components. There's a panel switch that I showed in the
previous picture that can turn
this circuit on or off and also can have a supply instead
of from the station batteries from some power
supply if I ever wanted to run the station on AC instead of DC.
That goes into that 80 amp boost regulator that was between the two
batteries that I showed earlier. I have a shunt resistor and an analog meter
to measure the instantaneous current being
used by the entire system. And the output of the boost regulator goes
to binding posts for further distribution.
And here is that further distribution. This is the connection point
from the left-hand side of the previous diagram. One side
goes to an unswitched power pole distribution for things like radios
that I'm going to use for both HF and VHF.
The rest of the distribution goes through a panel switch to select
either the HF or VHF equipment. And the HF
cable goes into a MIDI fuse box on another rack
shelf into the amplifier and a power pole distribution
for HF-only components like the screwdriver antenna and
the remote SWR meter. In the VHF
position, we have a high current and a low current connection.
The high current goes through a MIDI fuse box that I used in my
old minivan Rover to go to for
medium power amplifiers for the low VHF
bands. And another branch goes to
a power pole distribution system for low current
components like a small flex radio amplifier
fans, transverters, and an SWR power
meter power system. One little
branch circuit from the previous diagram goes through
a fuse box that can distribute unregulated
battery power. And the only component using that so far
is the computer. And we'll talk about that a little bit later.
Here's a picture of the station power distribution
shelf. So this is the connector I showed before that
was scary to put on because it was a live hot DC
that would have welded my tools if I wasn't careful.
The two fuses for the input DC from the
van. Here's the solenoid relays and the
relay timer for the delay of connecting the
station batteries to the van alternator.
Here's a first fuse box for
the distribution of battery power to three
different destinations, the most important of which is the
booster. And that
cable goes here to the front panel switch that selects either the
battery or a power supply for the input
to the booster. The booster is underneath this panel and comes out
here on the hot side and on the
ground side. So this is where the regulated voltage comes out from the booster.
That can be connected to directly or
another circuit goes to another panel switch
that allows me to switch to either VHF
distribution over here or to HF distribution over here.
Above that station distribution shelf
is an accessories rack shelf that includes a
system to power laptops that I no longer
use in the van, but that this was a big help when I
was transitioning off of laptops into
a permanently installed computer. On this side
are the three connection blocks that I talked about in the previous circuit
diagram. This is the direct station battery
unregulated, 12 volts from the station batteries that
go to the PC. This
power pole distribution block is the unswitched
power that goes to things like radios that I need for both HF and VHF
and here as you can see on the label is the power pole
distribution for VHF only components like transverters.
Now I'd like to talk about the build out of
HF and 6 meter amplifiers. There's a series
of photographs that show the build process just as an example
of how I built these things out for better or worse.
The HF amplifier is an
Amaritron 500N amplifier which produces about 400 RF
watts. This is the side of the
distribution that supplies HF only
power poles for other lower current devices and
we're going to see a series of construction pictures next.
Here's the amplifier mounted using a
piece of angled aluminum where I screwed in the
screwed in the aluminum into
existing screw holes for the
cover of the amplifier and then the vertical bolts bolt down into
the rack shelf.
After the amplifier I put in wood in the other spaces in order to mount
the rest of the system here and use for future
items here which turned out to be the 6 meter amplifier that I'll talk about.
Here's just mounting the main components in the
back and here we are wired.
Here's the high current connections to the
amplifier through these MIDI fuses
and one more branch goes to this small power pole distribution
and you can see this unusual connection of just the positive side. This is the
bias voltage which is a separate wire that goes into the
Ameritron amplifier. And finally
this is the system actually mounted in the van
with all the connections. Here is a
remote probe for SWR and
RF power that I connected to the output of the amplifier.
Here's several of the HF only components including this screwdriver
and that probe. Here's a PTT
line from the amplifier to hit the relay
during transmission for the amplifier. And finally
here's the power input into this shelf from the
station booster shelf, the picture of which I showed earlier,
with two 4 gauge cables that go down to that other shelf.
Now just this week I installed a 6 meter amplifier
that I had for a long time and a 50 volt power system.
So the amplifier needed 50 volts and I decided to
supply that with my first big lithium battery and also built
a switching monitoring and inrush board that I'll show later.
Here's the mount board for the 6 meter amplifier
that I used to help tie down that amplifier.
The legs go into these glued down PVC caps.
I have four eyelets for small bungee
cords to constrain the amplifier vertically and
these are four countersunk holes so I can put wood screws into the
piece of wood that's below this mounting board.
And here's the amplifier mounted next to the
HF amplifier. Now there's two years between
these two things. I built this shelf with the HF amplifier
two years ago and this was just this week that I put
the 6 meter amplifier in.
Here's a picture of that large 50 volt 50 amp
battery with some of the tools I used for the connections.
And here's what the battery
looked like. Before I put the restraining boards in
I put the battery in with the connector to make sure everything fit as I
expected before starting to make cuts. And as you can see
this is that AC distribution I talked about early
in my presentation. And here is the box for the generator.
So this little kind of cubby hole is otherwise
wasted space. So although I had to turn the battery on its side it was
a nice fit, a nice use for otherwise wasted space.
That cable from the battery is
mounted on a board and the board is mounted on the side of the van and this
represents a connection point for the battery. This allows me to connect or
disconnect the battery as necessary for my different operations.
Here's the 50 volt power
shelf that I built recently. This is
a box that contains a shunt resistor for
the metering system and a bolted down
midi battery. And this is the cable for
supplying the voltages to the battery
monitor here in the front. This is all in a
treasure box, a wooden treasure box from a hobby store, kind of hillbilly
engineering I call it. But I can close this lid to protect all these different
connection points. I'm kind of paranoid now that I'm 50 volts versus 14
volts. That can supply quite a shock.
Over here, maybe the most unusual looking part of this system is
these resistors connected in parallel, also mounted in
a hobby box. This is for inrush current
protection. What I saw when I used this amplifier
several years ago was that there was quite a spark
of very high current as the capacitors got charged up from
the capacitors, the amplifiers got charged up from the
battery. And that kind of big inrush of current is not good
for the battery and it's not good for the connectors. So a
feature that I included was an inrush current protection by forcing
the initial current to go through a total of
16 ohms that limits the current to less than 4 amps. And then
that rapidly degrades to allow me to give it
full power. Two switches on the front, one to
charge the battery through this conventional
power pole connection. So the charger gets connected here
and I have one position for the charge. The other position goes to this other
switch, one position of which forces the current
through the 16 ohm resistor for inrush current
limitation. And the other position, number 2 position, is a straight
connection into the amplifier without the resistors for normal operation.
And here, this is a meter that I
had removed to make room for this shelf and
this was just simply a convenient place to put this meter
that monitors the voltage for my booster and my battery
for the 14 volt system. So this has nothing to do with the 50 volt system,
it was just a convenient place because I have a limited amount of rack space.
And lastly, here's the whole system
configured for test. You can barely
see maybe the numbers on the meter
that shows instantaneous voltage amperage
and shows overall amp hours and watt hours.
So that's this meter glowing here. You can see the lights on over here
at the amplifier. This is actually an HF
dummy load that's supposed to go up to, as you can see,
it goes up to 30 MHz, but I used it because I didn't have any other
dummy load that could take that much power. It was a 1.6 to 1 SWR
at low power, so I didn't want to fire
this 6 meter amplifier up all the way. But I did verify
that it puts out 20 times the power that's put into it.
I tested it up to 600 watts with a FM carrier, so
I'm satisfied. It basically works and nothing smoked, so
it was nice to have that first test go well.
I have not yet installed VHF
equipment, although my VHF equipment is
battle-tested. I haven't installed the shelves, but when I do,
each band will be on one shelf. Each one will include a medium power
amplifier, which I kind of referred to earlier in a power distribution
schematic. I'll have a digital
SWR meter for probes for each band, so I can see the power
going out of each amplifier. And, as I mentioned,
all the VHF equipment is already contest-proven, so I have confidence that the
equipment I have will work. It's just a matter of
mounting it. The 10 meter
or 28 MHz IF that goes into the
transverter port will come from the milliwatt output of
the FlexRadio 6500. And I'll
probably have a manual switch for selecting which band gets
that IF initially, but I do want to
install an automatic switch so I can select
the band from the radio and have the IF switch
through a relay. And I have those components, but I want to do one step at
a time. It was good to talk about the power
first, but next I want to talk about the radio and computers in the van.
When I first started, and I made major
assumptions about power systems, I originally aimed to use
the Flex5000, which was my first 100-watt radio that I used
at home. It's well-suited because it has
transverter outputs and multiple RF and PTT outputs
that you'd expect from a flagship radio.
And the need for a good, powerful
PC for this SVR drove the decision originally to
use AC power for the van. Now what happened
after I installed the entire AC system,
one of my VHF club members offered a new generation Flex6500
for a surprisingly low price.
That latest series from Flex radio
includes self-contained computing power, so you don't need a big PC.
Got fantastic programmable interface for driving relays, that makes
some downstream work a lot easier than it would be
with any other radio that I know of.
It also has the same transverter and multiple programmable PTT
outputs as my 5000, and lastly, not a big thing,
but it's nice that it directly supports rack mounting. So I did buy that
even though I made a lot of expensive decisions
that were the foundation of which were
the assumption I was going to use the Flex5000. So I now have a Flex6500
in the van. And here
it is, mounted. Here's the front of the radio, which currently most of that is
obscured by my monitor, but I do have
access to the power button, that's the most important thing.
And here's the connections to the headphones and the
foot switch. And here's a view of the rear of the radio.
It's not the flagship of the line, but it has enough
connections to make things worthwhile, and you'll see
the most unusual connection for most radios is this Ethernet
connection, and that connects to my PC
in order to have a GUI for this radio, because you can see
on the front panel there are no conventional controls like a
VFO knob. Another radio I installed was the
ICOM IC7100. That was my first mobile radio for both
HF and VHF rover contesting. So it has
HF, it has two VHF, well I guess
three if you count six meters, three VHF or UHF
bands. So it's a
really nice, tremendous value radio and used as a
backup radio, maybe an IF for the microwaves, maybe
as a FM radio for just
making contacts to the local repeater. Anyway, it's a jack-of-all-trades
radio that turned out to be vital because
an older radio broke when I was on a major rove in Canada
and I was able to use that
IC7100 in the rove, preventing
a major disaster for that long trip.
And this just shows that IC7100 under test
and various components of that rack shelf
where the main unit of the IC7100 is tied down here.
This is PTT connections because it's a small radio
so everything comes out of this multi-pin connection
that allows me access to this. And this is an automatic
screwdriver antenna tuner, which I really don't use that much, but I had it
so I mounted it with the radio that it operates with.
Now again, another decision that was based on originally wanting to use the
Flex 5000 that needs a big PC was to get a desktop-class
rack-mounted PC. I had this built by a specialist vendor who
built PCs especially for that
series of Flex radios. Now, with the new generation, the
Flex 6500, it's overkill. I don't need anywhere near that amount of
CPU power, but I already have it so that's what I'm using.
Later on, I replaced the original AC power supply
from the vendor with a DC supply. In other words, what I mean by
DC supply is that it's a computer power supply, but instead of the
input being AC, it's DC. That thing was expensive,
but it eliminated the original need for the AC base station.
And again, boy, I wish I made that decision a year before, because
I spent a lot of time and money getting an AC base station built.
That
power supply accepts a wide voltage input, and
that voltage accepted is within the range of the raw battery, so I don't have
to regulate that voltage. I can just connect it to my
batteries as is through, of course, a distribution system
that I showed you earlier.
This PC works great with the new Flex 6500, and also works with the
older 3000 or 5000 lines, because it has a
good firewire connection. Now, what I did was
brought out the 5V and 12V from inside the PC
to a connector outside
for use of low current logic like Arduino boards
or relay boards, rather than having a separate DC power supply
for those components. So, I haven't actually used that yet, but that's going to
save some rack space and possibly save some additional source of RF noise.
And lastly, at least I have a video
adapter in there that supports a UHD 4K monitor,
not all built-in video systems of a
PC without a separate adapter would support a
high-def monitor, and that is a big deal to me. That's a big help.
So, here's a rack-mount PC, the back
of the PC anyway. Nothing very remarkable, except it does
take a lot of room in the rack, and it's kind of heavy. And actually, one of my
projects that I'm going to do shortly is to reinforce this, because I really
should have some weight support in the back of this
PC, rather than just laying it hanging from the front.
And just to emphasize again, this is the power input
to the PC, and that
DC input power supply is supplied through these
input terminals, where normally the modular AC connector would be.
My computer monitor is a 4K
monitor. It's kind of mounted kind of floppy, but I'm working
on an improved mount. There's enough room for an SDR interface
and many windows, and man, screen real estate is really vital
in today's ham contest. You have chat pages,
you have monitoring systems, you have your logger, you have a
rotator control. So, all these controls are
soft controls, so it takes a lot of
monitor real estate space.
Now, I use Samsung monitors. I used a smaller one before, and what
at least they used to. I don't know what the situation
is today, but many of the mid-range and above Samsung monitors
use a separate AC to 14 volt adapter.
I don't know of any other manufacturer that has a 14 volt input, so what's nice
there is, I can replace the power brick that takes AC
with a power pole connector, so I can directly supply DC voltage
from my station supply as the input into the monitor.
So, just a recommendation, if you want to
run your monitor from station power, look into the
Samsung monitors, and you'll have
a little bit of simplicity in one less brick, one less
source of RF interference.
And here's a picture of the operating
position, showing that monitor and the nice amount of
screen real estate. This is an old radio
they used to use. They used to use a Flex 3000. That's been replaced.
And here's one of the most important things I ever bought, which was a
battery-operated fan. And this is blowing right at my face, and it is
the difference between operating in 90 degree weather or not operating in 90 degree weather.
Remember, the van is off. There's no air conditioning in the van
when I'm operating, so having that fan be able to blow on me
is a huge help on hot summer days.
Next, I'm going to go quickly through
the progress I've made on microwaves so far in the van.
Now, I was just starting to buy
used microwave equipment, even in my minivan days.
That's kind of my normal pattern, where if I know
I'm going to go someplace down the road, if I see an inexpensive piece of equipment
being offered, I'll just buy it up knowing I would use it for the future.
Now, then a successful pack rat
that's my VHF club's name,
retired from roving, and he sold me his complete set of working microwave
bands from 33 centimeters or 903
megahertz all the way up to 24 gig.
They were put aside until I could work on them.
I concentrated first on the lower
five microwave bands, because they were interior mounted.
Physically, the 33 and 23 centimeter bands were
separate on two-tier wood mounts, and the
next three bands were all on one long plywood board, so I had
a project to separate all the equipment and mount them each on a rack shelf.
Now here's those three bands
on one big plywood board I talked about. What I did was,
believe it or not, and I can't believe it myself sometimes, I put that big
board on the... I did do a little bit of separation first, but
here, because they're so close together, but
I actually ran the table saw I showed you earlier,
I ran that table saw to physically disconnect
each of these bands, and then mount each band on a
separate rack shelf.
It's hard to see, but you can just barely see the outline of each shelf
in this bottom row of pictures. And here
are the first five microwave bands mounted in the
fourth rack. This is the rack that you can see directly
in when you first enter the side door of the van. So it goes
903 up to 5 gig. Down
the bottom here are two 12-volt batteries
about the size of a normal car battery, although they're deep-cycle AGM batteries,
and their charger. So this is the basic supply for
the power for the microwaves.
And here's a picture of the rear. Not terribly interesting, and a lot of
the mess of wires, those green wires and blue wires, are actually left over from
the old van, so I'll probably be taking those out before making the connections
on the back. Power requirements of the micros
included high current 26.5
volts, high current 12.6 volts for
the four low bands, and of course all the
bands require nominal 12 volts for transverters, etc., like most radio equipment
does. And I had a requirement for 5 volts for
TTL logic and USB.
My peak power estimate was 250 watts total.
Now one unusual problem was that these are, most of them anyway,
are Class A amplifiers, so there's a large current draw
whether or not there's RF applied. So one of my requirements is that I would
supply power only when the particular band was selected.
And the relays on my distribution board
should energize with grounding of the 24 volt
system, because that's the same procedure that's used for the
IF relays I had. The control
power supplies would be separate
and I'd want to monitor the current and voltages in the system.
So here's the board I built to meet
all those requirements. Central to it, of course, are these two power
supplies that have the two voltage outputs I
need, 12.6 and 26.5, and they are powered
from nominally 24 volts
from the two batteries that are on the bottom, the two 12 volt batteries
are in series. And the only reason I made that decision versus
a 12 volt supply at higher current was that I couldn't find power
supplies with these outputs at these currents
at anything less than a 24 volt supply.
Here are my meters in the front. I'll have a better view of that later.
Yet another shunt resistor
to measure instantaneous current and the distribution
of voltage to the
various components in the power supplies. Here are two
relays that I used to switch in from the front
panel, and here's my much smaller
5 volt power supply. Here is a
self-contained, I bought this as one unit, self-contained relay board
with four relays. This meets my requirements of only supplying power
to the high current amplifiers when their particular
band is selected. So you can see
that there's two connections for 26 and two connections for 12 volts
that are controlled by the relays, and then the
triggers here that are 24 volts, the triggers
are brought out in this smaller terminal strip. And over
here, this is meeting my requirement for the distribution
of plain old 12 volts to the various components like transverters.
And these are all powered from, of course, the 12 volt power
supply side. So, quite a lot going on in this board, and
this took me quite a long time to lay out all the components,
no less build it all out. Here's the front
power panel. The analog
amp meter is here. This is the battery monitor,
the battery voltage monitor that has a little graphic that shows how much power
is left, which is possible because they're AGM batteries rather than lithium
batteries. Here are three switches for turning on
the power supplies individually, and these are
meters, digital meters that monitor the
three different available voltages. The reason I went to all the trouble of having
separate switches for the power supplies was to limit
inrush current, so I could switch each power supply on in
turns. I mean, I could have done it, I guess, in a more
sophisticated way, but this was a simple solution to just
flip, flip, flip, and limit the total inrush
current to the system. And that's it.
If you're watching this video live at DEF CON,
I think we're going to have a live Q&A after this. If not,
if you're watching this video offline, you are welcome to
write me at my QRZ email address.