I finally completed my home office. I posted about many parts of it previously, but here are photos of the final setup:
I love having the ham radio and communications gear, but antennas can look unruly. Especially when you have five really tall ones. I’ve changed the antenna setup several times trying to find the right compromise between range and aesthetics, but ultimately decided to err on the side of aesthetics for daily driving. I can keep the other antennas behind the back seat of the truck for times when I might need the additional range. I opted to replace the CB antenna with a Firestik II, which is 2′ long. On the opposite side of the headache rack, I replaced the scanner antenna with a Browning BR-137, which is 22″ tall, and an adapter that converts the stud to NMO, and adds another inch or so. That antenna is seriously impressive. On the front of the truck, I replaced the factory FM antenna I never use with a stubby 4″ antenna, and the scanner antenna with a Comet SS-450SBNMO, which is 18″ long.
Also dealing with aesthetics, I wasn’t entirely happy with the appearance of the fifth wheel tailgate. I love not having to deal with opening and closing the tailgate when hooking up, but that’s about the extent of my appreciation of it. I’ve been looking for quite a while for a new tailgate, and found one for $425 shipped on Ebay, already painted black, with “a few minor blemishes”. I ordered it and swapped the hardware from my old tailgate over. It does have a couple areas that don’t look perfect, but from a few feet away you would never notice. I also removed all the graphics from the sides and back of the truck.
The antenna mount I was using was just a stud through some angle iron I mounted to the bed of the truck. It worked well for a while, but I found I had to continually tighten it, and when I went to this last weekend it broke. It couldn’t stand up to the stress of supporting the Tarheel, and the 6′ whip I used to run probably exaggerated the issue.
I decided to decouple the connection from supporting the antenna, and finally bought the overpriced Tarheel MT1S mount at $114. I considered fabricating something comparable in my garage, but don’t have all the right tools, which is something I hope to alleviate in the future. Once the part arrived I tried to used the built in holes with #10 self tapping screws to secure it to the angle iron. Those screws broke, and the drill bits I had broke as well when trying to drill them out. Instead of breaking more expensive bits, I found some #14 self tapping screws left over from another project, and used three of them to anchor it by creating new holes, in addition to the one successful #10 screw. I hope I never have to remove this antenna and bar, because the truck bed probably is a mess underneath from all the holes used to mount and ground these antennas.
I spent most of Saturday and some of Sunday trying to make a successful contact with my new setup. Our yard has limited options, but I found several locations I could set up the antenna and tried all of them. RX worked fine, but nobody could hear HF TX, even if only a couple hundred miles away. To make things a little puzzling, I was able to make a successful contact using just the 6′ whip from my Tarheel and the IT-100 antenna tuner mounted on the tripod in the same place I couldn’t make a contact with the 13′ whip and matching mechanism. Bypassing the massing mechanism didn’t seem to make much difference, either.
After I had enough messing with it, I finally pulled out the multimeter and found that there was continuity between the ground and the antenna stud, and that there was little to no continuity between the elements that made up the Mil-Stik whip. I requested a return with Alpha and they got back to me offering to send a new whip and said that the continuity between the ground and stud is normal due to the way the matching mechanism works. I asked that they process the return, or maybe consider an exchange for the Alpha DX SR which seems like another viable option that would fit my needs better since it has horizontal elements. They offered to send me both a replacement whip and a Alpha DX SR, so that I can test both and return whichever I don’t want to keep. While I’m disappointed in the antenna I received, that customer service is amazing. So I’ll give them another chance.
The box works well, but I need to find a better way to run the wires out the window.
VHF works great and I can easily hit all the area repeaters.
The Go Box I decided to build is almost done. I’m not completely satisfied with the foam cutouts and if I were to rebuild it today, I would locate the fan elsewhere. I still need to drill some exhaust holes for airflow, but other than that version 1.0 is complete. Lets have a look:
The inside of the box contains an Icom IC-7100, LDG IT-100, 350w PSU, and various cables. I’ll eventually add the ability to use an external DC 12v power source, probably with a bulkhead Powerpole connector. I used several side-by-side strips of 2″ industrial velcro to hold the radio to the bottom of the case, and the tuner to the radio, and they aren’t going anywhere. That being said, I really need to get a 3D printer or something so that I can start fabricating custom brackets for my projects. Or a CNC machine and some steel. I want to line up whatever brackets I fab up with the factory air holes to maintain as much of the intended thermal properties as possible, so just bending some sheet metal and drilling holes through it for the screws won’t work.
The outside of the box, showing the intake for a Noctua 80mm fan.
The outside of the box, showing the HF antenna input, VHF/UHF antenna input, shielded bulkhead RJ-45 connector for the head unit, and fused, switched, and EMI filtering AC input.
With everything connected, and the head unit/mic pulled out of the box.
The head unit only requires one shielded RJ-45 cable. I have a 50′ shielded cat6 that I store inside the box, as well as two 50′ coax cables for each of the antennas. With a 50′ AC extension cord, I can sit 100′ away from the power source and antennas.
I never had any intention to invest in ham radio outside of the truck, but that changed once I realized how much time I’ve spent idling in the driveway. I decided to build a portable setup that could be moved from house to RV with me, and even used outside. A lot of people seem to love, and a lot of people seem to hate the Icom IC-7100 radio, but it is the only radio on the market that meets all of my requirements for this project, so I decided to give it a chance. I’ve been told that it has display issues and that parts can be hard to find, but ultimately I decided to take the chance based on reviews I read online and the availability of an extended warranty from Giga-Parts (which I didn’t buy, but am thinking about). The reason this radio fits my requirements so nicely is that it is a HF/VHF/UHF rig in one, which is rare in itself, but allows for split operation with only a single RJ45 cable between the head and base. I can mount the base, antenna tuner, and power supply in a box and use a single 50′ shielded cable to access all bands.
The antenna I chose is designed for portable operation, and is perfect for camping. The Alpha Antenna kit covers 80m-6m and they have a jaw mount clamp to add an additional VHF/UHF antenna. With the heavy duty tripod upgrade it will weigh in at around 15lb and fit into a cylindrical bag just over 3′ long. Extended it can be used as a 21′ (ish) vertical antenna or have elements configured a few different ways for other types. They offer an element upgrade to hit 160m that I did not buy. I bought two 50′ RG58 cables to run from the HF and the VHF/UHF antennas back to the radio. Even though it claims not to require a tuner, I’m going to run a LDG IT-100 with it to ensure safe operation on all bands.
The box design is heavily based off of this idea, but for my needs will house an internal AC to DC power supply since between an extension cord, antenna cables, and the head unit cable, I can sit 100′ away from electric or the antenna. Plenty far for use in the home or RV. In the field it can run off of the RV’s inverter, generator, shore power, or my truck’s inverter, a portable generator, or a solar box I’ll eventually build. Instead of a toolbox, I’ll be mounting it all in a MCM box.
I previously posted about how my 30M APRS beacons were working, but seemed to be causing major RFI with the truck. I’ve done everything I know to do to track that down: add ferrite chokes, ground straps, etc, but have not found a solution. During my research, I kept finding myself back on this page. Unfortunately, when I ran the initial feed, which runs through a difficult to access port in the back of the cab to between the cab and bed (almost as difficult to access), I used a LMR400 cable just long enough to reach. The recommended method to choke the RF on that site will not work for me without replacing that cable, and even if I replaced the cable I couldn’t fit that assembly back there without removing the toolboxes, hitch, and bed from the truck for the install. Instead, I found this feedline isolation balun that exceeds the specs of the loop the site recommends building. It’s in a 4″ x 4″ x 2″ box that I will mount on the top rail of the truck bed behind the tonneau cover, and run the current feed into, and run another 1′ LMR400 feed to the antenna. All of this company’s baluns and isolation feeds have excellent (5.0/5) reviews on eham.net, including the one I bought. I also picked up eight Fair-Rite 18mm ID type 31 chokes to wrap the power leads in.
I installed the 30M APRS system today and APRS works great. I saw it gate at https://aprs.fi in both Brownsville, TX (300mi away) and Sugraland Run, VA (1290mi away, as the crow flies!). I was playing with TX power between 30w and 150w, so I’m not sure how far it travels with how much power. Of course I think that’s subject to a lot of conditions other than power.
Where this went wrong is shortly after installing it and getting it working properly, my truck began intermittently losing power. After a little while longer, several alarms popped up including ABS, StabiliTrak, Park Assist and Trailer Brake Controller malfunctions. I thought it was the radio, but after turning it off, pulling codes (none found), and clearing them anyway, the lights remained. It also seemed to have come on right after hitting a bump at 35mph, so I thought maybe something pulled loose. I spent a couple hours under the vehicle double checking all of the connections that seemed as if they could be related to those specific errors, but all were fine. I started the truck again and the lights were still on. After a while of idling while I searched online for potential fixes, the light went off.
With the light off, I began experimenting with the radio configuration. My findings were:
- 10.147.60USB (APRS freq), 30w transmit, no noticeable changes
- 10.147.60USB (APRS freq), 50w transmit, noticeable dip in truck power only when beaconing, no lights or warnings
- 10.147.60USB (APRS freq), 150w transmit, lights/alarms come on after approximately 3 beacons
- Keying up manually on 10.147.60USB does not seem to cause issues, but testing here was limited because it is data only
- Transmitting, even at full power, on 14.213USB does not cause issues
- Unplugging only the DATA port of the TS-480HX (TT4 connection to radio) ceases issues
- Several (unmeasured) minutes of idling clears the alarms
Since I don’t need HF APRS most of the time, I decided to leave it unplugged unless needed. I’m not really sure where to troubleshoot from here or how to fix this, aside from the several RF chokes I already tried (improved, not fixed the issue, and I don’t think chokes are the issue at this point.) When I do transmit, it seems 30w is going to be the practical limit unless I can find ways to eliminate the interference. I ordered some more RF chokes and ground straps to try.
As I’ve actually become quite interested in ham radio for more than APRS, I’ve been trying to find a good way to create a portable HF/VHF/UHF setup that can be moved from house, to RV, to outside, and loaned out to people I am trying to time-and-money-sink into my new hobby.
I found this setup which I really love, and wanted to post it here to keep for future reference: http://www.kj6vu.com/?p=873