Many thanks to Scott (VO1DR) who shares the following guest post:
Cheap and Bomb-Proof Field Package for the IC-705
By Scott Schillereff (VO1DR)
St. John’s, NL, Canada
Since getting my novice ticket in 1970 (WB9CXN) under the watchful direction of Charles “Rock” Rockey, W9SCH (SK), I have been a dyed-in-the-cloth homebrewer and QRPer. My one and only commercial rig before this year was a Ten Tec PM-3 I bought with paper-route money in 1971 (still have it). Fast-forward to today. I now live in Newfoundland, and Europe is as close as Georgia. I continue to build my station components and antennas. A recent sea-change though – I inherited some money and decided to splash out on a for-life rig that would serve well in the shack and on the road (RV or hiking). After researching options, I settled on the ICOM IC-705. A fantastic performer; a receiver like I’ve never heard before; more bells and whistles than I could dream of, and a form-factor like a….. delicate, expensive brick!
The 705 is not a sleek, trail-friendly radio. It’s on the heavy side and, well…awkward to pick up! But, man, what a radio! So, my first step was to buy a Windcamp ARK-705 exoskeleton. This protects the rig on all sides and gives you something to grab onto. I don’t mind the weight and size; I want this rig to be working in 25 years.
My operating interests are home use, mobile in my 25 ft motor home, and portable on day hikes. I’m new to POTA and SOTA but maybe that’s next, thanks to you, Thomas!
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.
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.
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!
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.
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!
My X6100 arrived this week and I did notice some noise on the receive audio when wearing headphones. It shows up as a 1000 Hz tone with a few harmonics and it’s loud enough to make the audio a bit fatiguing to listen to. The good news is that the noise disappeared when I added a mini line isolator between the rig and headphones. It also removes the hiss!
I like how the isolator is such a simple solution and imagine it could help other radios with similar issues. Often these noises and harmonics come from display noise. Also, your video certainly shows the improvement using an external speaker on the X6100! Thank you for sharing!
Several subscribers asked if I tried using the attenuator and RF gain to mitigate the level of overloading. Attenuators and RF gain can be an effective means of mitigating noise levels, but they essentially affect everything on the band–all signals somewhat equally.
A better approach is to use a BCI Filter.
BCI filters reduce or notch out AM broadcast band signals so that they don’t overload your receiver.
BCI Filters are placed between the radio and the antenna. They can have a dramatically positive effect if you live near a broadcast station and/or if you have a radio that’s prone to overloading.
I see them as a more “surgical” approach to solving broadcast band interference.
I had a conversation recently with a ham who upgraded his license for HF privileges primarily to do park activations in the POTA and WWFF programs.
He mentioned that he had a few successful park activations under his belt but was left scratching his head on a couple of occasions when he attempted a Park-To-Park (P2P) contact but could not be heard by the other activator.
He did all of the right things: announced his call sign followed by “Park To Park” twice and was patient while the activator worked a small pile-up.
In one case, he said the other operator had an incredibly strong signal–and having always heard, “if you can hear them, you can work them“–he was really baffled that he couldn’t make contact especially being a desirable P2P. His activations were successful so he knew it wasn’t an equipment issue.
He asked for my input, so I thought I might share a few points here as this is not at all uncommon–please comment if you think of others:
Big power, small antenna
Some activators operate mobile and don’t actually deploy their gear in the field. They simply drive up to a site, turn on their mobile HF rig in the car, and start making contacts with the mobile whip antenna mounted on their vehicle. There’s nothing wrong with this approach in the POTA program (just keep in mind mobile activations are not allowed in SOTA). Mobile activators can rack up numerous park activations in one day often regardless of weather or any site restrictions.
Mobile vertical antennas like Screwdrivers, Hamsticks and whips are quite impressive and, many activators swear by them. Not only do they work well in mobile situations, but they can also be quickly set up on a tripod in the field and many models can take a full 100+ watts of power.
If an activator is pumping 50-100 watts into a small, resonant mobile antenna, their signal is getting out there. But since their antenna might not actually have a lot of gain or efficiency on 40 or 60 meters, it can’t compete–in terms of reception–with a large aperture wire antenna.
In this scenario, the activator might be logging a load of stations, but they may not be able to hear your signal if it’s weaker than the others in the pile-up.
QRM on the other end
This is a big one, actually, and affects both park and, especially, summit activations.
Sometimes the other activator’s site is plagued with QRM (radio interference) emanating from power lines, nearby buildings, transmission equipment, and other electronic sources.
That QRM will not typically affect their transmitted signal, but it will have a dramatic impact on what they can receive andhear.
For example, I recently attempted to activate a game land I’d never been to before. On Google Maps satellite view, the site looked pretty darn remote and there were no buildings in sight. When I arrived on site, I set up my station, spotted myself, and started calling CQ POTA.
When I turned up the volume on the radio, it hit me that my noise level was a solid S8-S9! Turns out, there was a nearby power line that was spewing broadband noise across the entire HF spectrum. It was pretty much inescapable–there were no unaffected HF bands.
Had I really wanted to continue with that activation (I did not) I would have only been able to work stations with signals that were above my high noise floor. Perhaps one in five contacts at best. My chasers would have all been been left scratching their heads.
QRM isn’t always S8, but even an S5 or S6 noise level might wipe out 40-50% of the signals the activator can hear.
While hitting the field is usually the best way to escape QRM, there are spots that are as noisy an an urban neighborhood.
This is a big one; especially with the unsettled conditions we’ve had over the past couple of years. QSB, or signal fading, can be a proper obstacle in completing a contact.
If you’ve been watching my activation videos, you’ve no doubt seen chasers that call me with a 599 signal and when I respond to them, I hear nothing but silence. In those situations, I’ll repeat my reply with their callsign and signal report a few times in a row. I do this because QSB is a bit like having a three year old playing with your volume control while you’re on the air.
Seriously, imagine that three year old turning up the volume, then turning it back down, then turning it up again, and so on. It essentially has the same effect. Sometimes QSB is shallow and slow, other times it’s deep and fast–or it can be any variation in between (including deep and slow which is the worst).
In those situations as an activator, I reply a few times in a row with hopes to catch the QSB on the upswing so I can have a window of contact with the other station. When I do make contact, I try to keep the contact as short as possible so there’s hope for a complete exchange.
As a hunter, you have less control because your only hope is that QSB will be at the peak of signal strength when you call the activator.
If you’ve been doing park and summit activations for very long, you’ve no doubt experienced some “environmental distractions” during an activation.
I’ve been at parks before when the grounds crew were blowing leaves, mowing, and using other lawn equipment. It can be proper audio QRM especially if you don’t have an option to wear headphones to isolate those noises.
Sometimes the wind can cause a lot of extra noise. I’ve also been in shelters where the rain hitting the tin roof (while somewhat soothing) adds a lot of extra noise.
I’ve also been on summits and in parks where other hikers and passersby start asking questions while I’m in the middle of handling CW contacts.
They don’t understand that you’re actually in the middle of an exchange and need your attention focused. 🙂 For so many of them, it’s the first time they’ve ever seen/heard someone operating Morse Code and they’ve loads of questions. I hate to pass up an opportunity to promote amateur radio, so I’ll often pause the activation to talk with them.
If you know your radio equipment is functioning as it should but you can’t seem to grab the attention of an activator, keep in mind that it’s likely them, not you.
They’re not ignoring you, they simply can’t hear you.
The best practice for eventually making contact is to be patient and persistent. If you’re an activator trying to work another activator for a P2P or S2S (Summit To Summit) contact, keep sending P2P or S2S with your call. Often, other hunters will hear you and point out to the activator during their own exchange that there’s a weak P2P or S2S operator calling. More often than not, that’s your ticket to busting through!
Did I miss something? Please comment and share your thoughts and tips!
Thanks for all the interesting videos. I have a Icom IC-705 with the Peovi frame/handles and I found a clear plastic box that makes a perfect friction fit with the Peovi for a protective front cover. Thought I would pass on the info as I know people are on a quest for such a thing.