First Attempt to Build Mobile EMCOMM Go-Box. Help Needed.

First of all thanks for taking the time to look at this post, and my apologies in advance if a similar topic with answers to my questions has already been discussed.

I've been saving my pennies for nearly two years to purchase my first HF rig. I earned my Technicians' ticket back in 2009 but have mostly limited myself to local repeaters and simplex due to time constraints between work and school and my desire to "buy once and cry once." I had my eye really nice Yaseu FT-897D (mil-spec manpack case, tuner, batteries, that sort of rig) but lost in a last minute bidding war on eBay. In my persistance I went with my second choice: an Icom FT-7000; I ended up getting for less than $1,000 with all the mounts, cables, boxes, manuals, and in mint condition. Not a bad deal.

And this is where the saga of me wanting to build an EMCOMM station begins...

I work for a non-profit disaster relief organization in rural Appalachia. My territory covers some of the most diverse topography, both physically and technologically, so communications are a hodge podge of whatever works for one particular geographic area. We use MARCS, UHF, VHF, GMRS, GSM, and CDMA, and other I'm certain. But as always, Amateur Radio, is the most common thread. A local radio club installed a J-pole, and power supply to accompany the 2 meter that we had purchased, but experience has shown that I will not be in an office when things go sideways. Being an amatuer operator myself, I don't want to tie up organizational funds to purchase a commercial off the shelf solution, so I thought that I would build one myself. I spent nearly my entire Holiday break looking for a solution that marries up with many of the components that I have one hand which are: My new Icom 7000 and a Pelican iM2500 case. Not too many "things" but I believe that they are the most expensive components aside from antennas.

The design that looks the most simplistic and meets most of my needs is here:
http://www.ar15.com/forums/t_10_22/675680_.html&page=1&anc=11554342#i11554342


So bits and bobs such as wiring and the mounting plate, I'm left with finding a tuner and power supply.
For the tuner I believe that I'm going to be able to do some trading for a LDG style tuner, not really sure which one, so I'd like to hear your opinions. I was originally going to go with the SAMLEX SEC-1223BBM230 for a power supply but it ended up being .2" too long to fit inside the case. After searching some forums tonight it look like I may have a winner with the Powerwerx SPS-30DM Needless to say form-factor plays into this a lot. Fitting inside of the Pelican iM-2500 Storm case without making modifications that impair its ability to protect the station isn't an easy task.

I'd really like to hear everyone thoughts, opinions, or snide remarks. Like the title states this is my first build, I'd like very much to get it right the first time, and I'm certain with your help this will be a great project.

Thanks.

KD8MBN

 

I didn't see anything about the most important parts, the battery you are going to use and the way(s) you will recharge it. I don't see any math. What's the energy budget (i.e. how much power does it require) for that set up?

 

I agree with David AA9G. You would have portability, but will you have portable power? I have Go kit also in Pelican case but had to pack(Squeeze) in RigRunner for power distribution and a PWRgate for AC/DC auto switching from mounted a/c power supply and alternate d/c source.

I have small gel cell inside case to switch if A/C lost and a 2nd pelican case with larger power cell I can plug into the PWRgate. I can use included small gel cell for low power and or until larger external power is available.

All connections are PowerPole to allow direct input to RigRunner and or PWRgate. I have PowerPole equipped cables to allow power from external gel cell (Pelican Case2) and or auto battery.

Fellow hams use larger audio equipment cargo boxes with good results packing all in one case. For me, the down side is cases are too big.

Good luck with your project. Don't forget the "Power" angle and "Power" flexibility to be truly "Portable". Again as David AA9G stated, figure out your total power draw to make sure your wiring & power sources amp/hr exceed that amount.

73, Ray
Wx4pbc
Assistant Coordinator
Palm Beach County Skywarn
PCDARES AEC EOA 1
www.pbcskywarn.org

 

I use a tiny qrp (to conserve power) and size. Gel cell is a must and a portable solar charger maybe?

[video=youtube_share;g0jpuDde1h4]http://youtu.be/g0jpuDde1h4[/video]

 

This is kind of one of those "which is the best..." questions. There are as many answers as you can think of. Everyone has an opinion, and everyone has an idea. It is probably a good idea to spend some time on Google. Search for "portable HF" and click on images. You will find a lot of examples. Some are tiny, others are significant in scope. It just depends on what you think your needs are. And... (with 100% certainty) I promise that after you take it out in the field a couple times, you will find things you don't have that you need and things you incorporated that you want to change. It just goes with the territory.

For my own system... (Picture below) I have found that while it has everything I want, currently; I think it is a little on the bulky side and I am looking for a smaller case. This is a "DJ" rack case. They are also called rack case, anvil case, etc. I built this for field day, for last year. it worked great, but I think it is too bulky and would like to trim the case size down. Power is 2 X 35 Ah AGM batteries and 60 watts of solar panels. I have also found out that 60 watts of solar is not enough in the winter. There are not enough sun hours to keep things going unless I use supplemental charging from a car or generator. I also rearranged the radios after this photo. You can see the mic cords dangling in front of the HF radio. After field day I moved things around so the cords were not in the way of operating the equipment. The nice thing about this is that it just sits on my desk at home. If I need to go mobile I pull the main power feed off the back, undo the antenna feeds, put the lids on, and put it in the car and go. I have mobile HF antennas for field use. Plan B may be to split the uhf/vhf and hf radios into 2 smaller cases that will stack. I have not finalized the plan yet. Currently, the 2 AGM batteries are mounted in a plastic tool box. I mounted powerpole connectors and the charge controller in the tool box. The case in the picture has a battery meter, amp meter, 12 volt receptacle, and USB charger. The USB charger is RF noisy when something is charging and puts a "whine" into my signal when transmitting. I have not figured out how to suppress that yet. Other than that, the set up works quite well... for me.

Good luck with your build! Whatever you decide, it will be awesome... for you.

 

You do have some other considerations. You've got a great radio because of it's flexibility, and if you can mate it with the tuner LDG makes for the 7000, you'll have a winner there. That tuner will match about anything.

The Samlex supply should be OK. I use a 25 amp switcher from Radio Shack. It fits in a standard carryon bag with the 7000, tuner, and wire antennas with feedline. The Pelican or similar would be a good idea - there are some less expensive alternatives to Pelican out there that should work fine.

I'm assuming you have a source of reliable power. A small Honda generator is easy to move and easy to live with, and sips gasoline.