I built this contraption which holds my 50 watt Kenwood TM-V71A mobile primarily so I could get into AO-85 more easily since it helps to have a bit more power to get in full quieting.
It also holds a Bioenno 12V 9aH LiFePO4 battery. The shoulder strap harness is from Konsait, model number KS049. It allows professional photographers to have two cameras on either side of their body but also works well for us sat ops 🙂 It seems to be out of production but you can still find some if you look hard. I’m sure other manufacturers sell similar things.
The system keeps the radio off my stomach and out in front a little so the screen is easier to read and the controls are easier to control. Before I built this I used a Kenwood TH-D72A handheld radio to work FM sats. I now prefer this system because it frees a hand to control the radio.
Here are some pictures of it in action. Below my action pictures I have highres construction pictures of mine and pictures from other people who have made their own versions of this. Finally, at the very bottom of the page, I have construction information and dimensions so you can make your own version too.
Construction pictures
Other people’s versions of this
Loon NA1SA’s version
Loon was the first person I’m aware of who duplicated my setup. In December, 2018 he emailed me asking for detailed construction pictures and dimensions and I got that to him and added it to this webpage. Initially the page just had pictures of me using it and a few detail pictures of it. One good idea he had was to put some magnets on the left side to hold his mobile phone. I assume his case has some magnets in it too. Here’s a bit of what he told me about his setup:
I mounted the duplexer to the base board and added a magnet to hold my cell phone in place so I can monitor the pass. That should help eliminate the need for paper. Prior to the passes I mark out the AOS az, Max el, and LOS az using a compass and …. yup …. golf tees. I also have small orange cones in the event of being on hard top. Here’s the updated photos.
Pictures of Loon’s system:
Michael K4KMP’s version
Michael is the second person I’m aware of who duplicated my setup. He emailed me about it in September 2020. He actually had a woodworker do the work, who did things a little differently, including some nice changes for aesthetics, but a few changes that didn’t work functionally, which Michael corrected. In his own words:
I had to make adjustments after I received it because the battery was too tight so I made the holes bigger; I also made a hole to pass the battery cables through … Some things I’m still trying out; I may permanently drill the mic holder on the side; right now it is just holding up with command strips. The hover grip is great to hold the phone with.
Pictures of Michael’s system:
David W4OFO’s version
David made a version of this in October, 2020 and one change he made was to add a belt buckle support which takes all the weight off your back. In his own words:
I made a modification to your brace. I added a piece of sheet aluminum to the front so that it tucks in behind our belt buckle. It completely takes the weight off of your back and shoulders and the straps are just used to hold it close to you. I also wrapped the aluminum in waterproof gaffer’s tape so it doesn’t scratch my kitchen table even though I filed it pretty smooth. It also gives it some height so that the coax isn’t touch the table it sits on and putting pressure on the ANT connector. (See pic) I also added a volt/amp meter and a piece of velcro to hold a spare battery for my recorder. The velcro strip is also used to hold the meter in place too on the piece of wood that holds the main battery down.
Pictures of David’s system:
Charlie N3CRT and his Icom IC-9700
This is something Charlie recently showed me on Twitter he made which is similar to the FM mobile radio body support system, but for a much larger Icom IC-9700. He says it weighs 22 pounds without the antenna.
I don’t have any more information about it other than what he said in the tweet:
Construction information
FM Mobile radio and body support system for satellite operation
All boards are made from 1/2 inch plywood.
Screws are #6x (1 1/4″ / 31.8 mm) multi-material construction screws
Bolts for battery hold down board are 5″ long 3/8 in – 16
The angle between the radio and body board is approximately 70 degrees.
Radio board
7 1/4″ width x 8″ height
Body and battery board
13″ w x 9″ h
length at dip in the curve is is 6 3/4″
Battery hold down board
6 1/2″ w x 1 1/2″ h
5″ bolts
Eyebolts for shoulder strap are cut to 2 3/4″
Strengthening boards
These are the little “wedges” that wedge in the corner between the radio and body boards.
Top wedge
Top surface: 7 1/4″ w x 1″ h
Bottom surface: 7 1/4″ w x 1 1/8″ h
Bottom wedge
Top surface 7 1/2″ w x 1 1/4″ h
Bottom surface 7 1/2″ w x 1 7/16″ h
I listed the top and bottom surfaces dimensions as that should produce the 70 degree angle you need.
spacecomms 