Tag Archives: Scott (KA9P)

Scott’s Icom IC-705 “Shock Box”

Many thanks to Scott (KA9P) who writes:

Enclosed are a few detailed pictures of the system I’m using to protect my Icom IC-705 in the wild.

I wanted a system that would protect the radio from shock and vibration when I dropped it in use, or tripped over a cable, as well as when in transit.

Some research lead me to Sorbothane, a commercial vibration damping material available in small lots on eBay, and to a Sorbothane applications engineer. The engineer recommended that a good way to protect electronics is to use a “box-in-a-box” concept where the equipment resides in an inner box with vibration dampers between the inner box an outer box.

Sorbothane’s on-line calculators suggested that for the IC-705’s weight, some relatively small pads on each wall would be adequate.

So I started with the bottom 4.5 inches of a Harbor Freight ammo box, and added four 1/4 inch thick, 1 inch by 1 inch Sorbothane pads to the bottom and two long sides.

Then I added an aluminum plate to the inside side surfaces of the pads, and lined the plates with neoprene (see the drawing above). The neoprene adds a bit of additional padding, but primarily lets the 705 slide into “the inner box” while putting a little bit of pressure on the pads. The manufacturer recommends a slight loading pressure on the pads for proper damping.

The radio is fastened into the box with an adjustable depth 1/4-20 threaded locking knob, positioned to put a little force on the back wall vibration pads when tightened down.

The cover is made of aluminum angle stock and Lexan, and provides good protection for the front of the radio when not in use.

This “shock box” solves a lot of problems for me.

1) I can leave the cage on when operating, using dongles out the front for things I want to change like the antenna, mic, battery power, headphones or paddles. Leaving the radio in the box avoids field handling errors, to which I am prone.

2) If the internal battery needs to be changed in the field the radio comes out quickly by removing the single 1/4-20 knob and screw. But the battery can be charged in the case with a USB or power plug dongle, again avoiding handling.

3) The depth of the box protects the entire periphery of the radio front, much like the handles do for the sides of a cage, and the radio remains enclosed/covered on all sides except the front. I’ve used it in snow and rain without issues when the wind isn’t bad.

4) Impact protection is really high other than for a direct frontal panel hit within the box. The plastic box takes the first hit, deforming a bit and transferring the rest of the energy to the vibration damped inner box. Not worried about dropping the radio anymore.

5) The use of Sorbothane’s “box-in-a box” with vibration pads concept leaves a channel surrounding the radio to promote air flow and heat dissipation. For me this is much better than using the radio in a box cushioned with foam, which blocks air flow and can trap moisture.

6) The box provides a handle, which the 705 really does need in the field.

7) The footprint of the Harbor Freight box is just about a hand and glove fit in the bottom of most serious packs, making it easy to carry when backpacking.

On the downside, it’s a bit ugly, but it’s cheap, maybe $40 US to build. Other than wanting a gasket to provide better weather and dust proofing when closed, I’m happy with it.

-Scott (KA9P)

A bit ugly? Scott, I think it looks great!

I feel like shock absorption is one of the things lacking in many of the IC-705 cage solutions out there. I always feel like when a metal/aluminum frame is paired with a hard plastic chassis, in a field drop the plastic will be the weak point. 

This adds to the bulk of the IC-705 (in terms of overall size) but likely doesn’t add a lot of extra weight. In your manpack/chest pack situation, this is a great bit of engineered insurance for your $1300+ rig!

Thank you for sharing!

The Elecraft KX2 version of Scott’s chest plate/manpack

Many thanks to Scott (KA9P) who writes:

As a follow-up to my previous post: this chest pack is still a bit of a work in progress but has been tested and works as is. I didn’t want the non-IC-705 owners to feel left out 🙂

The Condor MCR-3 chest plate can be used with a Condor T & T pouch (30 bucks) for most QRP rigs with a KX format.

The Condor T & T pouch is a frequently reviewed favorite of hikers and hunters – YouTube videos abound. The key feature is the way the pouch opens from a chest plate, or just straps, to form a tray. I expect you could modify other clamshell pouches of other sizes with an adjustable cord to do the same thing. I haven’t seen other pouches built to do this, yet.

The “tray” section contains a number of MOLLE loops as well as some loop material. This makes it easy to fashion your own radio attachment system. I have been using some hook material fastened to the back of KX2 for now, but am working on something that locks in, rather than tempt fate. Continue reading The Elecraft KX2 version of Scott’s chest plate/manpack

Scott’s Icom IC-705 manpack built on a Condor MCR3 chest plate

Many thanks to Scott (KA9P) who writes:

Here’s a MOLLE-related [piece of field kit] you may not have seen yet.

My summer 2022 QRP /PM rig is built around a Condor chest plate – not really a pack although there is a plate carrier compartment that thinner things store in easily enough. And I often have a small accessory pouch in the chest plate.

The key ingredient is the IC-705 adapter plate, made from scrap 0.06 inch thick aluminum scrap.

The four tines that fit the chest plate MOLLE webbing are spaced per the MOOLE/PALS standard of every 1 1/2 inches, but the tines themselves are 3/4 inch wide rather than 1 inch to make them easier to insert in the chest plate.


The plate is attached to the 705 with M4 by 10 socket head screws. I first used a single quick disconnect 1/4-20 photographer’s knob, and it worked, but eventually would loosen enough that the radio would start to swivel.

The orange strap that retains the adapter plate at the top of the chest plate is riveted to the adapter plate with plastic POM rivets. The chest plate is a Condor MCR3, about 26 bucks on eBay.

The radio goes in and out of the chest plate in less than a minute, and the adapter plate can be removed in a minute or two. The radio is very stable and easy to operate.

As a bonus, the loops also hold a Buddistick mast section, then a Versatee with a Buddistick.

With the antenna in front, I can change bands and adjust the whip and coil while standing. The antenna also goes in and out of the chest plate quickly.

I’m finding it’s great fun to listen and operate on the way to and from my operating destination. Definitely the easiest /PM set I’ve had. Every control and jack, and the battery, is easily accessed with the radio attached to the plate.

It’s like the 705 was intended to be used this way!

72, keep up the great work.

Scott ka9p

Absolutely fantastic pedestrian mobile setup, Scott! I love how the custom IC-705 mounting plate makes such a stable surface for the IC-705 to be suspended as you operate. As you say, you also have very easy access to all of the station components.  Brilliant!

Thank you for sharing your design notes and photos!