Ham Radio EMCOMM Go Kit – Power Box v3

About two years ago I built a new version of my Power Box, which turned out pretty well and performed great. I liked the smaller form factor and versatility of it, however, the build-out was a little cludgy and didn’t make the best use of the equipment (having to open the lid to see the power meter was less than ideal).

This new build makes use of the large Tac-comm carrier I previously used for the HF module in my Go Kit. In the year since that version of the build I decided to go a different route regarding this part of my kit, so I had the carrier available for reuse. This build is essentially a re-casing of the same equipment I had in the previous power box; the only alteration is the circuit breaker. I replaced the generic, no-name unit I had been using with a genuine Bussman RV style circuit breaker. I also changed the circuit breaker to one with a 35 amp trip instead of 40 amp. This was done because all of the West Mountain gear I am using for this build (PWRcheck & Epic PWRgate) are rated for 40 amps and I wanted the breaker to trip before potentially damaging any of this expensive equipment. I won’t be using much over 20 amps at any given time, so this shouldn’t restrict my operation in any way.

As luck would have it, all of my power box devices fit perfectly inside the larger size Tac-comm carrier. There is plenty of room to wire everything and this layout also provides the massive benefit of mounting the circuit breaker and power meter in the front of the case. This makes turning the unit on and off and checking my state of charge and power consumption super convenient. The front mounting plate is made of a sheet of ABS plastic mounted to a section of aluminum angle that is bolted to the carrier. The PWRgate is mounted to the carrier using velcro strips which hold securely while also allowing for easy removal. I had a few different ideas for how to mount the battery, but I ended up using 12 squares of super heavy duty velcro. Each square can hold 2 lbs and the battery weighs under 11 lbs, so it shouldn’t be going anywhere. I also added some padded strips to the top half of the carrier to keep the battery from shifting.

The end result of all this is a much more convenient and versatile power box. The weight increased slightly to 17.25 lbs, but it’s more compact overall and the build quality and looks are much improved and due to the slits in the carrier, the LED indicators on the PWRGate are still visible so there really isn’t any loss in functionality. It’s also super easy to work on, just remove 4 screws and the top cover comes off for access. I think I might have finally found the ideal power box configuration.

Ham Radio EMCOMM Go Kit – Radio Cases v4

I’ve been building and rebuilding my go kit for a couple of years now and every time I do it I learn something. What I learned since I built my last version is that I really value versatility. When building a go kit you should think about what you need the kit to do and how you will be using it. The two previous versions of my kit (see here and here) both used rack cases to contain the radios and other equipment in one complete package. This works great for multiple reasons: it provides a lot of protection, with the covers on the cases are dust proof and water resistant, the cases are stack-able and the operator has easy access to all the radio’s ports. There are two big negatives that go along with rack cases as well: they are bulky and they add a lot of weight.

For my new go kit build I wanted to cut the bulk and weight of my kit substantially (I did some math and found that for my previous VHF case the rack case itself weighed more than the radios inside it). I also wanted to divide the kit into more versatile modules so that I only have to carry what I need in a given scenario. This is a similar idea to what I did when I rebuilt my battery box; going smaller and simpler instead of all out.

To achieve this goal I decided to use Tac-Comm tactical radio carriers. These carriers are made of aluminum, are lightweight, they stack on top of one another, tilt bales & handles are included and they offer a lot of flexibility for how you can mount equipment. On their website they emphasize the use of nylon webbing straps to secure radios, power supplies, etc. That’s fine, but I prefer to bolt things solidly in place. These carriers are not weather tight, so in the event that I need to expose them to inclement weather I will keep them inside a plastic bin to prevent equipment damage. In the end I used three carriers: two standard size (for power supply & VHF/UHF) and one large (for HF).

The power supply module uses the same Powerwerx power supply I have used on all the previous builds. It works great, is compact and doesn’t put out RFI. I mounted it in the standard carrier using the same brackets as previously and added two Anderson powerpole ports to the back of the case. It’s a very straightforward build. I thought about putting a top on the carrier, but leaving it off gives me an easy way to store the power cord and radio power jumper wires. I removed the standard tilt bale to allow for stacking on top of the larger carrier. Including cables the power supply module weighs 5.6 lbs.

The VHF/UHF module uses the same Kenwood TM-V71a and SignaLink USB combo I’ve used in the past. The radio is mounted in the carrier using the standard mobile mount. I added an ABS plastic plate in the back of the carrier to allow a place to mount a USB pass-through port and a powerpole. This provides a convenient place to hookup when in the field and gives every internal cable a place to land so nothing is loose and flopping around. The layout I chose leaves space on the side to mount the microphone inside the carrier for easy transport. Tac-Comm also sells covers to protect the front and rear of the carrier and I used a front cover with an ABS plastic extension to protect the radio’s display & knobs as well as keep the microphone cable inside the carrier. To top it off I used Tac-Comm’s steel top cover which is magnetic and allows for the use of a small mag-mount antenna for instant field deployment. The VHF/UHF module weighs 7.9 lbs.

The HF module uses the same Yaesu FT-450D transceiver I have used before, but this time I changed my digital interface. Instead of a SignaLink USB I decided to use an inexpensive USB soundcard wired directly to the radio’s data port and I key the radio via it’s serial port using rig control. I chose this soundcard because I know from previous experience that it has a low noise floor and works well for digital communications. This new arrangement saves a lot of space and allows me to reduce the carrier to its minimum height without sacrificing any functionality. The transceiver is mounted to the carrier using the same angle brackets as previous builds, only the hole placement is different. Similar to the VHF/UHF module I used another ABS plastic plate for USB & powerpole connectivity and another optional front plate for protection. I also was able to mount the microphone internally for transport. The HF module weighs 15 lbs.

The end result of all this is that I now have a very versatile and vastly lighter go kit. Since each radio and power source are separated from one another, I no longer have to carry anything I don’t need when going to the field; if I’m going to run on battery, I can leave the power supply module and vice versa. Even as a complete kit I reduced the volume of equipment by at least 50%. All together this new kit weighs 28.5 lbs, compared to 40.5 lbs for v2 and 52.25 lbs for v3, a reduction of 30% and 45% respectively. Needless to say I am very happy with the end result. Any protection I have sacrificed is more than made up for by the additional versatility and reduced weight.

Ham Radio EMCOMM Go Kit – Power Box v2

I only built the previous version of this box a few months ago, but I learned a lot from building that case. The main thing I learned is that rack cases aren’t necessarily the best option for a power case. Rack cases are great for radios because they provide ready access to the front and rear of radios and other gear. For a power box the extra lids, bulk, and weight of a rack case don’t provide enough benefit to overcome the drawbacks. I also quickly realized that I really don’t need an inverter. I found a very compact and high performing 12V adapter for my laptop that makes the inverter unnecessary. This all combined with the awkward power wiring and inadequate power monitoring of my previous case pushed me to rethink my power box.


I wanted a case that would make the most of the small size of my 40 Ah lithium-iron-phosphate battery. The one I ended up using is only $15 at Lowes. The battery sits in the case and is kept from shifting by stacks of cardboard cut and glued to fit the taper of the case. This works well to keep the battery stable while allowing for easy removal when needed. The power circuit is wired with 10 AWG wire and the battery is fused using 40 Amp ATC fuses.

Power System

From the battery the power flows through a West Mountain Radio PWRcheck. This device is an inline power monitor that measures voltage, amperage, power, and amp hours. It can also log power usage and provide a battery gauge when the battery’s amp hour rating is input via the unit’s control software and USB connection. The PWRcheck can also be setup to alarm at low and high voltage along with other features. The PWRcheck then feeds a WMR Epic PWRgate. I used this device in the previous build and it works well as a battery charger in addition to channeling power from solar, battery, or power supply inputs to the output. Both the PWRcheck and PWRgate are mounted using heavy duty velcro, the PWRcheck to the top of the battery and the PWRgate to the side of the case. This allows for easy removal, while also securely holding them in place. The PWRgate’s solar and power supply inputs and its power output are wired to powerpoles mounted to the outside of the box. All wiring was done using 10 AWG wire except the solar which is 12 AWG since it doesn’t carry as much current. I also used blue & gray powerpoles for the solar connections to differentiate them from the others for easy identification. The final piece of the power system is a WMR RIGrunner 4005 mounted to the outside of the case using heavy duty velcro. This allows flexibility to either provide power distribution from the case itself or move the RIGrunner to another location and provide power from there via an extension cable from the power box. All of the power system devices are rated for 40 Amps of continuous current which is more than enough for my purposes.


I really wanted to keep this build super simple and flexible while maintaining a lot of functionality and I feel good about how it turned out. The case itself is just the battery, power monitoring and a charging/distribution system. Everything is modular, light and there aren’t any unnecessary devices or wiring. This new version of the power box weighs in at only 16.5 lbs, a little over half the weight of the previous build. My previous go kit total weight was about 70 lbs (radios + power) and the new arrangement totals about 69 lbs. This doesn’t seem like much of an improvement, however, since I rarely need both radio cases I end up saving quite a bit of weight for real world applications. For example, a Field Day or QSO party deployment (HF + power) with my new cases totals about 46 lbs, over 20 lbs lighter than my previous iteration and over 50 lbs lighter than if I used my lead acid battery. I especially like how much less bulky this version of the power box is and the ease of portability that this provides.

Update (June 2018)

After using my new power box for a little while it became apparent that it would be a good idea to have a more convenient way to turn off the power, and therefore minimize any discharge from the battery, than simply unplugging the main powerpole connection. To this end I decided to remove the fuses and in their place put a 40 A circuit breaker. This breaker is bolted to the outside of the case, making it very convenient to access compared to the fuses. This change also necessitated rerouting some of the wiring, but I think it ended up better arranged than before. I used the power box in this configuration for Field Day with my solar panel and everything worked perfectly.

Ham Radio EMCOMM Go Kit – Radio Cases v3

This third version of my go kit is more of a revision than a compete rebuild. After using my previous build for about a year I realized that while it is nice to have everything in one box, it is also a lot of extra weight and bulk that I don’t necessarily need. For the most part, when I operate a portable radio station I don’t use both HF and VHF/UHF, so carrying both is excessive. The solution for this is something I considered while planning my previous build, splitting the kit into a HF unit and a VHF/UHF unit.

HF Case

In order to keep this revision simple I tried to keep the shelf layouts as similar to the previous build as possible. The HF case reuses the lower shelf of my previous kit with only small modifications. The shelf was mounted in a 3 unit shallow rack case. The removal of the upper shelf from above the HF radio necessitated moving its SignaLink to the top of the power supply where it was attached using heavy duty velcro. This arrangement led me to remove the HF radio’s external speaker since there is now unobstructed space above the radio which allows for decent sound projection. The power wiring is also very simple. I kept the power supply output powerpoles as they were and added another powerpole connection for the HF transceiver. This allows for easy access to either connection. I also changed the power supply’s power cord to be removable; the previous build had it wire tied in place which turned out to be an awkward arrangement. Finally I added a new rack panel with a USB pass-through for the SignaLink. The HF case ended up weighing 29.5 lbs (including lids, microphone, and cables).


The VHF/UHF case reuses the top shelf from my previous build and includes several modifications. The shelf was mounted in a 2 unit shallow rack case. The biggest change was the addition of a dedicated power supply (Astron SS-12). In order to hang the power supply from the shelf I removed the top cover of the device and mounted it to the shelf using #8 hardware and fender washers. Then the power supply was reassembled. The bolt locations were chosen to avoid the internal electronics of the power supply while still distributing the weight of the device.  The SignaLink and microphone connection had to be re-positioned to make room for the power supply. The separation of the radios also necessitated eliminating the powered USB hub. As in the other case the power supply output and radio power input were pulled out to the back of the case for easy interconnection. Finally I reused the rack panel from my previous build to provide access to the dual-band transceiver’s antenna and the SignaLink’s USB connection. The VHF/UHF case weighed in at 22.75 lbs (including lids, microphone, and cables).


Each case can be used by itself or as a pair. When used independently a jumper can be used to power the radio from its associated power supply, or an external power source can be used. When stacked I can use the HF case power supply or other sources (like my Power Box) to feed a RIGrunner which distributes power to both radios.

Either single case configuration results in me saving at least 10 lbs compared to my previous kit. If I do need both, the total weight is more (52.25 lbs vs 40.5 lbs), but since it is split between two cases it actually makes it easier to move. This also has the benefit of not physically tying both stations together. I can deploy somewhere and one person can operate the V/U station and another the HF and they don’t have to be sitting on top of one another. In the end I think this is a much more versatile and useful setup than my previous go kit.

Ham Radio EMCOMM Go Kit – Power Box

In the months since completing my revised go kit earlier this year, I have been considering building an improved version of my battery box. I wanted to use the same style of rack case that I used for my go kit and at the same time add a lot of versatility and functionality compared to what my basic battery box offered.


  • Reduced Weight
  • 12V Power Output
  • 12V Charging, Switching and Distribution in the Box
  • 120V Power Output
  • Battery Voltage & Current Monitoring
  • Solar Compatible


Reducing weight meant moving away from the lead acid battery that I used previously. These work fine and are not overly expensive, but they have a lot of limitations. My battery box used a deep cycle battery that weighs about 55 pounds. This new build uses a Bioenno 40Ah lithium-iron-phosphate battery that weighs about 10 pounds. It is also significantly smaller and can supply power for a longer period than my old battery. These batteries are not inexpensive ($360), however, they should last through significantly more charge-discharge cycles than a lead acid battery and when combined with the weight and space savings these benefits justify the price.


To handle the battery charging, power switching, and solar power requirements I used the West Mountain Radio Epic PWRgate. This device is a major step in evolution compared to other power gate products in the past. Older units could automatically switch power between a battery and power supply in addition to trickle charging the battery when the power supply was on, but they were only compatible with lead acid batteries. The Epic PWRgate supports multiple battery chemistries and charge rates, making it much more versatile (you select the battery chemistry and charge rate by removing the cover and setting two jumpers to the appropriate values). It is also much more efficient with a reduced voltage drop and no large heatsink. It can take inputs from a power supply, battery, and solar panels while it simultaneously outputs power. Depending on the state of each it can charge the battery from the solar panel or power supply, or direct battery power to the output if the power supply is unavailable. To complete the DC output power distribution system I used the 5 port West Mountain Radio Rigrunner from my old battery box.


While not always required, I wanted to have the option to power or charge devices that use 120V. To accomplish this I added a Samlex 300W Pure Sine Wave Inverter to the system. While this is a fairly low wattage for an inverter, the intent of this is to power devices such as laptops, monitors, HT battery chargers, etc. that don’t require a lot of current. I went with a pure sine wave model since they produce much cleaner power, which should help reduce RF noise as well as work better with whatever electronics I am using.

Power Monitoring

For battery voltage and current monitoring I used a standard 1.125″ digital DC Voltage Meter and a Blue Sea Systems Shunt Current Meter. This current meter can measure current in both directions which allows me to monitor both the current draw under load as well as the charge current depending on how I am using the system at that moment. I wired the power inputs for both meters through a switch so that when I don’t need to monitor the state of things I can turn off the meters. This is very handy at night when you may not want bright LEDs shining in your face.


The DC power wiring consists of an inline Maxi Fuse Holder connected to the battery’s positive terminal. I used a 50A fuse for the main feed and 8AWG wire. This is routed through the current meter shunt and into a 4 circuit Blue Sea Systems ATC Fuse Block. I used 2 of the circuits:  a 30A, 10AWG feed goes to the PWRgate and a 2A, 16AWG feed is used for the meters. The battery’s negative terminal was connected directly to a Blue Sea Systems Busbar. The inverter was wired directly to the current meter shunt and the common busbar. I also ran a ground wire from the inverter ground terminal and through the hole in the back panel. This wire was terminated with a green powerpole for easy connection to a ground rod and serves as a safety ground for the AC circuit.


The case itself is very similar to that used in my go kit, except this box is a 3 unit shallow case instead of a 4 unit. The shelf is the same model used in my go kit. All of the components were mounted to the shelf using 8-32 & 10-32 machine screws. I had to get a little creative to figure out how to secure the battery to the shelf. In the end I used 3 heavy duty jumbo wire ties to cinch the battery to the shelf and 2 nylon spacers secured with 10-32 machine screws to prevent the battery from sliding laterally under the wire ties. So far this arrangement seems very secure.

The front and back panels were made using 11/64″ thick sheets of ABS plastic. The front panel required notching in the bottom corners to allow for the shelf mounting screws as well as ventilation holes for the inverter fan. The back panel features a large cutout for the inverter outlet & switch and serves as the mount for the PWRgate & Rigrunner. I also added section of 1″ aluminum angle to the back panel which adds a lot of rigidity and prevents flexing when power cables are plugged and unplugged. One unforeseen modification involved the rear case lid. Since the PWRgate is mounted in the center of the case, it’s powerpole connections protrude just enough to make contact with the center brace of the lid. I debated moving things around, but in the end I notched the lid brace using my Dremel and a small cutting wheel. Due to the tight packaging, the jumper wire from the PWRgate to the Rigrunner has to be removed when putting on the lid.

Go Kit Integration

Since the PWRgate is now separate from my go kit I had to modify my go kit’s power wiring to accommodate this new arrangement. This involved adding a powerpole distribution block and permanently mounting the power supply output to the case. For full charging and battery backup capability jumper wires have to be run between the power supply in my go kit to the PWRgate and from the Rigrunner to the new distribution block in my go kit. I tried to organize my jumper cables the best I could to keep things as neat as possible and I used very flexible 10AWG wire with silicone insulation to minimize any cable stress and tangling. When stacked, the two units integrate together very well.


All together the power box weighs just under 31.5 lbs which is pretty good in my opinion. I’ve added both capacity and a huge amount of capability compared to my old battery box and it still only weighs about half as much.

Ham Radio EMCOMM Go Kit – Solar Charging System

Field operations using batteries are very common and my battery box is a very convenient source of power. For longer term operations, however, keeping the battery charged is just as important. In order to supplement my battery system I put together a small solar charging system.


  • 50 Watt, 12V Solar Panel – Renogy
  • 10 Amp PWM Solar Charge Controller – Renogy
  • 1″ Aluminum Angle

The goal here was to have a simple solar system that would be large enough to charge my battery box at a decent rate, while still being small enough to transport easily. I also wanted to keep the costs fairly low.

I went with a 50 watt solar panel since it is fairly compact (around 2 ft square), inexpensive (about $80), and puts out almost 3 amps at peak sun. The charge controller (under $30) prevents the panel from overcharging the battery when the sun is out and blocks the panel from discharging the battery when the sun goes down. The aluminum angle frame holds the parts permanently together (which simplifies field wiring) in addition to holding the panel at a 30 degree angle. A 30 degree panel angle is a good compromise for my latitude and helps maximize the panel’s sun exposure throughout a full day. All together the panel, controller, and frame weigh about 12 lbs.


I used this setup with my battery box and go kit for Field Day this year and it performed very well. I generally do digital only on Field Day and made over 160 contacts using PSK31 and RTTY with the radio set for 50 watts output. With the sun out, the panel kept up with my power usage and by sunset the battery was essentially fully charged despite me operating for several hours. I continued to operate after sunset and quit around 1AM. I resumed operating mid-morning and the few preceding hours of morning sun had recharged the battery back to near full charge.

As with any battery testing, the current draw is the deciding factor for how long your charge will last. Since Field Day is in many ways a contest I was transmitting quite a bit which increased my current draw compared to more casual operations. Overall I operated around 16 hours and never drained the battery below 12V. If I turned the power down, I could probably operate the entire 24 hours and dropping from 50 to 25 watts would have minimal impact on my ability to make contacts.

Update (June 2018)

Along with upgrading my power box, I also wanted to upgrade my solar charging capability. Since I already had a 50W panel, I decided to buy another of the same size from Renogy and make my own folding 100W panel system. I used basic zinc plated hinges and keep the panels folded using a simple bolt and aluminum plate system. The bolts also provide points to allow the attachment of aluminum legs to keep the panel tilted at a 30 degree angle to pick up maximum sun. I also mounted a comfortable handle to make the panel system easier to carry. The two panels are connected in parallel and then connected to the power box via anderson powerpoles. This allows the panels to charge my 40 Ah lithium iron phosphate battery via the Epic PWRGate inside the power box.

I used this setup during Field Day this year and it worked very well. We had a mix of clouds, sun, and some rain but the panels were capable of keeping up with my HF digital station (running at 50 watts). In full sun these panels will charge the battery with about 6 amps, more than enough to keep up with the radio’s average power usage which is about 3 amps (mostly receiving, transmitting  about 25% of the time). This keeps the battery more or less topped off during the day. I didn’t operate all night, but I did put in several hours after the solar panels had stopped producing power. In the morning the panels came to life again and charged the battery back up some even while I was operating. By the time I packed up I still had about 28 Ah left in the battery according to my PWRCheck. Overall I am very happy with my new power box and larger solar panel system.

Boafeng UV5R USB Soundcard Interface

I recently purchased a Baofeng UV5R5 to throw in my Go Kit as a backup handheld and I decided to build an interface to be able to send and receive digital signals. The interface was intended to be as simple and inexpensive as possible, much like the radio itself.

VHF/UHF digital EMCOMM transmissions in my area typically use the MT63 mode which is very robust and can work quite well using only acoustical coupling. While this technique works surprisingly well, it has limitations. If the area you are operating in is too noisy, your audio is too weak, etc. the data transmission can have issues getting through correctly. It also doesn’t work very well for modes other than MT63.

USB soundcard interfaces are very common, I have multiple SignaLink USBs myself, but they are definitely overkill for this application. After some experimentation, I built this simple interface for under $20.



The main idea for this project was to replace the external speaker microphone functionality with that of the USB soundcard. In order to do this I used the speaker mic cable and wired it to two 3.5mm stereo audio cables such that the speaker output from the radio connects to the microphone input of the soundcard and vice versa. Each splice was soldered and insulated with heat-shrink tubing. The entire joint between the three cables was then secured with more heat-shrink tubing. Each 3.5mm plug was marked with colored electrical tape to make it easy identify which cable plugs into which port of the soundcard (red for microphone, green for speaker).


To operate, I plug simply plug in the cables and connect the USB soundcard to my computer (a big advantage of this model of soundcard is that it does not require special drivers for Windows 10 or Linux, it is truly a plug-and-play device). When I am ready to send data I simply key the radio using the PTT switch on the side and click the transmit button in the digital software. When the transmission is finished I unkey the radio. I had originally played around with an external VOX circuit as well as the UV5R’s internal VOX feature, however, neither of them would reliably key the radio and stay keyed throughout an entire data transmission and I decided they were unnecessary. Using manual keying is actually somewhat of an advantage since it simplifies the interface, reduces complexity, and doesn’t require changing the radio’s configuration.


I used FLDIGI to test the interface over simplex to another radio. After some experimentation I found that with the radio’s speaker volume set at a comfortable level (about 1/4 turn) a setting of 50% for the soundcard’s microphone gain was a good audio level for receiving data. For transmitting, I found that a setting of 1% from the soundcard’s speaker produced the cleanest output.

If I was going to build more of these I think I would add a 10K ohm resistor at the connection between the soundcard’s speaker output and the radio’s microphone input. This would attenuate the signal somewhat and allow for finer control over the transmit audio level. Even so, as it stands now the audio is clean and data transmission worked flawlessly. I have used this interface on my local digital net and it performs very well. This has definitely found a place in my Go Kit.

Update (March 2017)

I recently discovered that FLDIGI has a built in TX Audio Attenuator feature. Using this I can achieve much finer control over my transmit audio level, even with the soundcard’s speaker output set to 1% volume. This makes adding a resistor in the transmit audio wiring unnecessary.

Ham Radio EMCOMM Go Kit – Version 2

Last year I put together both VHF/UHF and HF go kits. While functional, neither of these was as capable or robust as I ultimately wanted my go kit to be. My new goal was to build an all-in-one station in a box that was not overly bulky or heavy.


If you look around the internet you will see a lot of people building go kits in rack cases. I always liked the sturdiness and modularity of this type of case, but not the bulk. Most builders us a full size 6 unit case, which is not compact (roughly 24″ square and 13″ tall) nor lightweight (over 18lbs). After evaluating the equipment I planned to use in the kit I realized that I did not need a full depth case. Using a shallow case saves me 8″ of depth and cuts the weight as well. I laid out several possible equipment arrangements in CAD and found that if I kept the kit fairly barebones (no SWR meters or external antenna tuners, only one external speaker) I could also move from a 6 unit case to a 4 unit and still fit everything I needed. The 4 unit shallow case I used is 22.4″ x 16.2″ x 9.1″ and weighs 12.8lbs.

The general design philosophy for this project was to have all of the equipment mounted to two shelves (one on the bottom and one at the top). After my experiments in CAD I found that a good organizational layout was achieved with the power supply, power distribution, and HF transceiver mounted on the bottom. As part of the power distribution system I wanted to incorporate an automatic backup power switch. This allows the power system to seamlessly change from AC wall/generator power to battery power. While not necessary, this is a nice feature to have because it prevents your radio from turning off while operating if there is an interruption of power (which can easily happen in emergency and field operations).

This left the VHF/UHF transceiver, speaker, and two SignaLinks for the top shelf. The SignaLinks are separated by the speaker to easily differentiate which unit is connected to which radio. I went with multiple digital interfaces because while I will most likely never be transmitting on both V/U and HF simultaneously, it can be very handy to be able to monitor both at the same time or to monitor one while transmitting on the other. Having two units also allows me to never worry about changing radio and SignaLink wiring to operate on the band I need to.

In order to simplify the cabling between the SignaLinks and my laptop I decided to us a powered USB hub and to make the USB hub accessible on the back of the case. This makes it very convenient when in the field since I don’t have to reach into the case to plug in the interface cables. The addition of a rear mounting plate gave me a place to pull out the V/U transceiver’s antenna connection for easier access as well.

I decided one external speaker would be adequate based on the layout I settled on. In this layout there is a fair amount of space below the V/U radio’s speaker to allow for sufficient sound output. The HF radio, however, has much less space above its top mounted speaker. Another consideration I made was that FM audio on V/U is generally very clean, especially compared to SSB audio on HF. Based on this I chose to use the speaker with the HF radio.



The Powerwerx power supply is perfect for go kits. It is very compact (6″ x 5″ x 2″), has convenient Anderson powerpole connections on the front (in addition to terminals on the back), and can be secured with mounting brackets.

The Yaesu 450D offers a lot of bang-for-your-buck and is relatively compact and lightweight as well (9lbs). The built-in automatic antenna tuner does not have the widest range (3:1), but I don’t plan to use it with non-resonant antennas so it should be more than adequate. Making use of the internal tuner also allowed me to eliminate an external tuner from the design, which was one of the key reasons I was able to fit everything inside a 4 unit case. The 450D was mounted using 2.5″ steel brackets along with M4 machine screws and 1/8″ nylon spacers to prevent the brackets from rubbing against the radio’s enclosure. I had originally intended to use Yaesu’s mobile mount for the 450D, however, it took up too much space and would have affected my layout. This arrangement lifts the radio about 1/2″ off of the shelf which should provide plenty of ventilation.

In the preliminary layouts I had planned to use a West Mountain Radio PWRgate and Rigrunner for backup power switching and power distribution. This plan proved impractical due to space restrictions, however, I found the perfect substitution in the Low Loss PWRgate. It is about half the size of the other backup power switch and it provides 3 output powerpoles which eliminates the need for a Rigrunner or other distribution block. While the LLPG is rated for 25 amps vs the 40 amps of the other unit, this should still be adequate for my purposes. The LLPG is very lightweight and was mounted using heavy duty double stick tape.

The Kenwood V71A was mounted using it’s mobile mounting bracket. The voltage converter for the USB hub was screwed to the shelf using its mounting tabs. The other equipment on the upper shelf was mounted using either heavy duty velcro (SignaLinks, USB hub) or double stick tape (speaker). I also added some rubber strips to the bottom of the speaker because I found in test fittings that the clearance between the speaker and the HF radio was only about 1/8″ and I didn’t want any inadvertent contact between them when the case is moved.

Cable Management

Part of eliminating the Rigrunner from my build meant that I had to provide some protection for the power wiring and radios. This was done using inline fuse holders with ATC style fuses. I also had a fair amount of radio interface and USB cables to manage. The shelves I chose are vented which makes them perfect for using wire ties to secure everything in place. I also wanted to make the go kit as straightforward as possible to assemble and disassemble. Part of this goal was limiting the wire tying of cables to individual shelves. This means that if I want to remove a shelf, I only need to disconnect the handful of cables that are connected between the two shelves (two power, one speaker audio, one SignaLink), then unscrew the shelf and pull it out. No cutting of wire ties is necessary.

I really wanted to be able to stow the radio microphones inside the go kit and I found that I could velcro the V/U radio’s mic to one of the HF radio’s mounting brackets and the microphone’s cable would then fit nicely between the power supply and HF radio. This is especially convenient since the microphone jack is in a position that makes disconnecting it a bit of a pain.

The HF radio’s mic is stowed using velcro and a strap to the inside of the front case lid. The lid has enough depth that the mic can fit without contacting the front of the power supply. The power supply AC power cord is stowed using a similar strap method as the HF mic, except it is in the rear case lid.


Part of the goal of using a smaller rack case was to cut down on weight as well as bulk. I had estimated that I could build the go kit and keep the weight around 35lbs. In the end the kit weighs 40.5lbs. I think the lesson I took from this is that wire and mounting hardware add up to more weight than you might realize.


The kit is very straightforward to setup. Once the lids are off I simply unstrap the microphones and power cord. Then I can either plug in AC power or a battery, hook up my antennas, connect USB to my laptop, and I’m on the air. I am very happy with how little bulk this kit has; with the lids removed the case is only 12″ deep and easily fits on a small table. The kit is small enough to integrate perfectly into my home station, which makes it very convenient to make sure everything is fully functional for field operations. I am very pleased with how this kit turned out and I learned a lot of along the way, especially about case layout and parts fitment.

Update – Microphone Connector (February 2017)

After using my Go Kit for a few weeks I realized that the Kenwood V71’s microphone connector was not in the best location. It is on the side of the radio and when the mic is being used it twists and otherwise stresses the microphone’s connector. To improve this situation I decided to extend the radio’s mic connection to the front of the Go Kit. I accomplished this using a 1 foot ethernet patch cable and a RJ45 Inline Coupler. The coupler was mounted on the top of the power supply with heavy duty double stick tape. This new arrangement makes the microphone connection much more accessible and greatly reduces the stress on the connectors.

Update – Integration with New Power Box (November 2017)

Part of building my new Power Box involved modifying the power circuitry for my go kit. Because the battery switching components are now off board I no longer needed the Low Loss PWRgate. In its place I installed a Powerwerx PD-4 distribution block. I also used a powerpole mounting clamp and a piece of ABS plastic to create a mount for the output of my power supply. This gives me two solid points of connection from which I can wire to my power box. Or if I am running exclusively off of the power supply I can use a simple jumper for self contained operation.

Ham Radio EMCOMM Go Kit – Antennas

Mast System

My first priority was to have a good VHF/UHF antenna system. A magmount on the roof of your car is OK, but for local line-of-sight communications the gain and height of your antenna are very important. I also wanted something that I could easily transport and erect by myself.

Antenna Mast (2)After some investigations I decided to aim for a simple lightweight mast system that I could mount to the trailer hitch on my car. The base for this setup is a hitch mount flagpole mount. For the mast I chose the MFJ 1904H. This mast solves a lot of potential problems for a portable mast system:  it is 5 feet long when collapsed making it easily transportable in my car, it is non conductive and will not interfere with any antennas mounted on it, and despite being made of fiberglass it is fairly sturdy (each tube wall is 1/8″ thick). I don’t intend to heavily load this mast so this should serve my needs well. In order to achieve a tight fit between the flagpole mount and the mast I used a section of 2″ PVC pipe as a spacer. When fully extended the top of the mast is about 21 feet high.

I also purchased a 33 foot version of this mast design from Max-Gain Systems. While this version requires some guying, the additional antenna height can greatly increase performance.


Antenna Mast (3)Antenna Mast (1)For the VHF/UHF antenna I chose the Two Way Electronix Dual Band Slim Jim. As someone who uses a J-Pole antenna as my base VHF antenna, I am very familiar with how well these antennas perform. The Slim Jim is a J-Pole made from 450 Ohm ladder line so that it can be rolled up for easy storage and transport. I mount the antenna to the mast using a nylon bolt and wingnut the passes through the insulation at the top of the antenna and a hole drilled in the top fiberglass section. This setup is very light weight and has virtually no wind loading which makes guying the mast unnecessary (under average wind conditions).


For HF I did considerable research regarding what type of antenna is appropriate for emergency communications. A lot of ham radio is focused on making contacts at great distances (DX). This necessitates a low angle of radiation from the antennas being used. For a dipole this means that the antenna should be at least a half wavelength above ground. The most common HF bands used for EMCOMM are 40 & 80 meters (one half wavelength on 40 meters is about 66 feet, 132 feet for 80 meters). For EMCOMM purposes, however, we generally only need to communicate within a couple hundred mile radius of our location. This requires a Near Vertical Incident Skywave (NVIS) propagation path. It turns out that this makes our lives a lot easier since a dipole can be used for NVIS when it is mounted much lower than it would typically be. Instead of trying to get a dipole very high, mounting it at 15 to 20 feet is ideal for this application. Another benefit of this approach is that at this height the dipole loses almost all of its directionality and is essentially omnidirectional.

HF Antenna #1 – Loaded Dipole

My 80/40 Loaded Dipole was built specifically to be center supported by my 21 foot fiberglass mast. It is lightweight, only 76.5 feet long (59% of a typical 80 meter dipole), and resonant on both bands.

HF Antenna #2 – End Fed Half-Wave

Similar to the Loaded Dipole, my 80/40 End Fed Half-Wave antenna is resonant on the two most common EMCOMM bands. It is also only 76 feet long (58% of a typical 80 meter dipole) and is quick and easy to deploy in the field as a sloper when a single strong support is available.

HF Antenna #3 – Folded Skeleton Sleeve Dipole

Field Setup (1)Field Setup (2)When space and strong antenna supports are available my 75/40 meter Folded Skeleton Sleeve Dipole makes for an excellent EMCOMM antenna. It is resonant on both bands and is only 107 feet long (81% of a typical 80 meter dipole) making it somewhat more space efficient without reducing performance through the use of loading coils like my Loaded Dipole and End Fed Half-Wave.

HF Antenna #4 – Hamstick Dipoles

Antenna Mast (4)In an effort to maximize portability and reduce both setup time and the footprint of my antenna system I bought 80 and 40 meter versions of MFJ’s hamstick dipoles (MFJ-2240, MFJ-2275). These are heavily loaded antennas that use a base section consisting of a coil wound on a fiberglass rod with a stainless steel whip on the top. While a small loaded antenna will not have the efficiency or the bandwidth of a full size antenna, it is considerably smaller (15 foot span). The dipoles are lightweight and my fiberglass mast seems plenty strong enough to support them.

Performance (updated February 2017)

I have done 24 hour WSPR tests of both the Loaded Dipole and End Fed Half-Wave antennas and they perform similarly, which is to say they are quite effective antennas. I used the End Fed Half-Wave during Winter Field Day and was able to easily make contacts on both 40 and 80 meters using both SSB and PSK31.

To test the Folded Skeleton Sleeve Dipole my Ham Radio club used it during Field Day 2016 and made over 350 contacts. They even loaded it up on bands other than 80 and 40 meters and it performed well. I would say this is definitely the best antenna of the four, however, it is also the largest and heaviest.

I have yet to do much with the Hamstick Dipoles, but I plan to do some testing in the future.

Ham Radio EMCOMM Go Kit – HF

HF Kit (1)After some thought I decided that I wanted to treat this as more of a HF Field Kit than a true Go Kit. I had heard good things about the Yaesu FT-450D and after seeing sale prices and mail-in rebates drop the price to $600 I decided to buy one. The Yaesu (9”W x 3.3”H x 8.5”D, 8.8 lbs) is not as compact as some HF rigs, but it is nowhere near as unwieldy as my Kenwood TS-590SG  (10.6″W × 3.8″H × 11.5″D, 16.3 lbs) which serves as my main HF transceiver in my station. For such a compact radio it contains many comparable features to my larger and considerably more expensive Kenwood.


The Yaesu 450D is an entry level transceiver, however, it includes a lot of features that give you considerable bang for your buck.

  • HF/6M Coverage
  • 100W Transmitter
  • IF DSP Filtering (Width, Shift, Contour, Notch, Noise Reduction, etc.)
  • Backlit Buttons (perfect for field use at night)
  • Voice Keyer (perfect for contesting and Field Day)
  • Built-in Antenna Tuner

Field Case

HF Kit (2)To house the Yaesu I used a Monoprice 22″ x 14″ x 8″ Weatherproof Hard Case. This should keep the radio, SignaLink, and microphone secure. Less damage prone items like the power cable can be transported in my backpack. For additional capability I decided to add a second case to the kit.

Accessory Case

This case is the same model used to house the Yaesu 450D. In this case it contains my Manual Antenna Tuner, a MFJ 4125P 22A switching power supply, and a MFJ 822 cross-needle SWR Meter. This case greatly expands the capabilities of my HF kit. The manual tuner has a much wider tuning range than the autotuner inside the 450D, the switching power supply allows me to power the radio from line or generator power if available, and the small SWR meter is perfect for station monitoring in the field.

When line or generator power is not available I will rely on my Go Kit Battery Box. I think that this setup will prove to be versatile and the Yaesu 450D provides many modern conveniences as well as 100W output in a compact package.