Tech

Portable Radio

An article on Dan Romanchk’s web comes from our own expert in portables! Here’s a guest post by Ed Jones, K8MEJ. If you’d like me to publish a guest post or yours, please email me….Dan I like to operate portable, whether it’s my new interest in operating amateur satellites or my love of HF. My family has a travel trailer and I’ve been taking my ten-year-old son camping since he was three. When we go camping, I usually bring along some ham radio and my family tolerates an hour in the morning and an hour in the evening listening to atmospheric noise, hearing me shout my call sign in the mic over and over trying to be heard in some distant land, and my giddy excitement when I work an ATNO from the campground. These rack-mount units house my IC-7300, IC-9700, KPA500 and a 30A power supply. I also occasionally operate at Scout events that are one to five days long, activate a rare county each year for the Ohio QSO Party, or sometimes just go set up in a park for a few hours and play radio. For all of these occasions, I found that transporting and setting up my radios, cables, batteries, etc. would take 20-30 minutes to set up and again to put away. That’s in addition to setting up any antennas and feedlines. So, my goal this year was to both simplify and expand my portable operating kit. I wanted to greatly reduce any setup and tear down time for the radio(s), speed up antenna deployment for quick outings, and for longer outings have a rotatable gain antenna. I’ll write about portable antennas another day. This article will describe my progress so far with building “go boxes” for my radios. I had been keeping an eye out over the last couple of years for ideas on how to make my gear more portable. I live close to Xenia, Ohio so going to Hamvention each year is akin to going to my local hamfest. I had examined the options from a company called iPortable. They make some kit that is better looking than most of the homebrew go boxes I have seen, but the final result does not have that minimal, clean look I prefer. Still, for those who value function more than form, it’s a good option. Other vendors had go box offerings on display, but nothing I saw really excited me. So, I kept looking for better ideas. Somewhere along the way, my Googling brought me to Novexcomm’s website. They make semi-custom go box kit that from the front looks nicer than iPortable’s kit. They’re easy to work with, and they are pretty quick to turn around some customizations. Bob Burchett is a super nice guy and will spend all the time you want from him on the phone. After some back-and-forth with Bob, I pulled the trigger on a 6U rack mount case, a mount for my IC-7300, a mount for my IC-9700, front panels with speakers, his version of a Powergate board, a 30amp power supply, and a rear IO panel with the connections I requested. At first, I was excited when I opened up the box. The front panels looked nice and aside from Novexcomm’s logo plastered everywhere, it had the minimal, clean look I was looking for. But as I began to put things together, I determined that I wasn’t really all that happy with how they mount the radios in the case. Novexcomm and iPortable use shelves that mount in the rack. Novexcomm machines a thin aluminum front panel that you mount over top the rack shelf. The front panel is ok, and the rack shelf is ok, but the brackets they provided to mount my 7300 and 9700 radios were simply pieces of bent aluminum bar stock. I needed to drill into the bottom of the shelf and attach the brackets and then use the provided thumb screws to attach the radio to the brackets. The screws they provided to attach the brackets to the shelf were too long and interfered with the thumb screws. That was a silly oversight. In addition, there wasn’t a single fuse or protection device in the entire kit. There is nothing to protect the Powergate board and no fuses or circuit breakers for the power supply. And finally, while basic installation instructions were provided, there is zero documentation on how the Powergate board works, no troubleshooting information, and no where I could find to download firmware updates. Once completed, it’s sturdy enough for light duty use and to be transported on the rear seat of my truck, but I wouldn’t trust it for rough transport or on a plane. But really, how many hams do that? Truth be told, for the average weekend ham, it’s fine. But I ended up spending a lot of time doing re- work on the Novexcomm box to fix a faulty battery bracket, get different screws for the radio brackets, install fuse links on every DC line and on the AC feed to the power supply, install a switch to turn the fans on or off, and install a master battery switch. When it came time to rack mount my Elecraft KPA500 amplifier and matching KAT500 tuner, I knew I wanted a mount and panel that was much sturdier. The KPA500/KAT500 combo is heavy, and I didn’t want to use a shelf with a thin front panel. And if I was going to spend so much time modifying something I thought would be more turn-key, I might as well spend the time to specify exactly what I wanted. So, I went to back to Google to see how I could do better, and I found SNS Engineering. Elecraft lists SNS Engineering in their recommended third-party vendor list. I was immediately impressed with the 3D drawings for their rack mount panel for my KPA500/KAT500. SNS makes replacement side panels for the amp and tuner, which add captive nuts to attach the custom aluminum side brackets. These are full-size side brackets, not thin strips of aluminum stock I used to attach my radios to the shelves. These side brackets are then attached to the back of the front panel, which is made from ¼” thick high-strength aluminum. The brackets are attached to the back of the panel with blind screws so the front panel is as minimal and clean as you can get. SNS Engineering are true craftsman. Installation was a snap and I had the case built in no time. I decided I’d work with SNS to custom design a rear rack panel for the amp/tuner box so I wouldn’t have to reach inside the case to connect cables, coax, and power when I moved the amp/tuner between portable use with my IC-7300 and my Flex 6400 at home. In the meantime, I built up the Novexcomm 6U radio box and the SNS 4U amp/tuner cases and hit the road. KE8BOV and I went camping for three days and spent two days DX’ing and the third day operating the Ohio QSO Party from a rare county, as has become our yearly tradition. I quickly realized that having the IC-7300, IC-9700, power supply, 20Ah Bioenno battery, cables, and rear panel made for a heavy 6U case. I wanted to reduce the weight of any single box and I opted to have each radio in its own case and to move all power to its own box. This provides for a very modular system, though it does mean more boxes overall. I’m younger than the average ham, but I also didn’t want to risk a hernia! Since I would now have four separate boxes instead of two, I’d need new rear I/O panels for the radio cases in addition to the amp/tuner case. And it also meant more re-work. But hey, this is my first attempt and it would be silly to expect perfection right away. Working with SNS Engineering on the design for the rear rack panels taught me a lot about what goes into designing and manufacturing fully custom equipment. It’s a lot more complicated than I ever imagined to properly engineer a product. That’s why I think Novexcomm has a good solution for the average ham. They make it simple to get a decent looking product, but if you’re willing to spend the time and money, you can do much better. SNS Engineering spent way more time than they probably should have and was very patient working around my impatience just to be done. In the end, we had to specify and agree on every single item on each panel, right down to the specific switch, circuit breaker, bulkhead connector, fan, guard, etc. At first, I didn’t want to deal with all the detail, but as they would send me 3D drawings, I began to realize that details really do matter. In the end, the front and rear rack mount panels from SNS are far and away higher quality than anything else I found and certainly better than anything I could build on my own. So, what would my advice be to anyone interested in building a go box that looks more polished than something the average ham can homebrew? First, if you have a mobile radio you just want mounted in a box with a speaker and some antenna jacks, the iPortable box is good and relatively inexpensive. If you want something with a little cleaner front end but don’t want to spend many hours researching specific components, mounting hardware, and layout, the Novexcomm products are pretty decent. Just take note of my comments above and address them before you place any orders. If you want something for a stationary rack at home or you want the highest quality rack mounts for your portable rack cases, SNS Engineering is the way to go. I’ve not fully finished the project. I’ve learned a lot along the way, and I want to revisit some of the decisions I made. It means spending more than I originally thought I’d spend, and it means more re- do work, but it’ll be done right in the end. I plan to have SNS Engineering machine the rear panel for my IC-9700 box and the font panel for my power box. I also wish I had chosen to have rear panels the full size of the box instead of smaller panels. However, there is one advantage of using a 2U rear panel on a 3U box, for example. If I’m running solely on battery power, I don’t want to run the fans unless I absolutely have to. Having some open space means that unless it’s very hot outside, I’m operating in the sun, or running very high duty cycle, I can leave the fans off and conserve a bit more power. The fans in the radios and amp will keep the electronics cool. The fans on the back of the case just keep hot air from getting trapped in the case if it’s hot outside. The purpose in writing this article is to describe some of the considerations you need to make in designing portable cases for your equipment and to review some of the options I found. I purposely left out a lot of the technical details because this article is long enough already. However, I’m happy to answer any specific questions you might have. You can contact me by looking me up on QRZ.com. As they say, “I’m good on QRZed”. Or, in our case, you might just tap him on a shoulder at a DELARA meeting!