Practical Portable with the Icom IC-705 and Other Radios
Richard Constantine G3UGF goes out and about with the IC-705, reviewed last month.
Last month I reviewed Icom’s IC705 transportable transceiver. This month I’m exploring some of the first-generation accessories from Icom and third parties plus a few universal items I’ve found for myself, that can be used with the 705 or other equipment.
Backpacking
The ‘Field Operations, multi-function Backpack’ is a strong feature of Icom’s advertising encouraging operators in their words to, “Be Active” − licensed listeners (those with licences but largely inactive) take note.
While some radios may only see the occasional excursion, the LC-192 backpack will doubtless appeal to many EmComms (USA), Raynet and SOTA operators. It might just inspire more couch-potato amateurs to take to the great outdoors, who knows?
The IC-705 definitely needs weather protection, for outdoor use. However, I was somewhat sceptical about the need to spend significant money on a dedicated backpack.
Nevertheless, knowing that a serious camera bag typically costs much more and as I love travel and /P operating, I thought the LC-192 was worth a closer look.
Fig. 1: The author, out and about with backpack. Fig. 2: The backpack antenna mount.
Figs. 3 & 3a: inside of the mAT-705 Auto Tuner. Fig. 4: Alternative battery packs.
Fig. 5: One alternative for a desk stand.
Fig. 6: Using a photographic desk stand.
It was immediately clear that it’s been specifically designed for radio with its rather unusual composite strengthening plate on one side − more on that later.
There are cunningly concealed cable access points above and below the side plate. You have to dig around a little to discover them as the bag only comes with a minimal diagram. There’s a more obvious top edge flap for either a cable entry or a whip antenna.
Both upper and lower compartments have separate, top quality, weather protective zips. The lower flap has inbuilt multiple pockets for small items such as connectors, cables, tools, notebook, pens and similar.
The upper radio compartment has two shock absorbing pads on which the radio sits and there’s a small securing strap and ¼in screw arrangement that fits to the underside of the IC-705 to hold it in place. There’s also a small pocket inside the top compartment to store the fixing screw when not in use – nice touch.
There are four hook and loop, movable, padded inserts in the lower compartment. The most rigid of these must be fitted centrally to support the radio above. When not needed for further vertical divisions, two of them can be used to support each side of the bag. The fourth and softest pad fixes laterally to hold items in place.
Externally and to the right there is a net bag that also has an upper fixing strap. This can easily secure a lightweight collapsible pole or antenna parts.
The shoulder straps are padded with fixings for things such as pens and torches, etc. There’s a waist strap, top carry handle and air vented padding for the wearer’s back. While carrying out a splash test ensuring that rain easily runs off the special fabric and it does, I was pleasantly surprised to discovered a hidden, full height pouch between the back padding and the bag itself, making it practical to store a tablet for data mode operation, APRS or logging, a wire antenna, coax or perhaps a map.
Verdict
Having now used it I wouldn’t want to be without it. It’s practical, well-made and reasonable value for the flexibility it provides. Having one compact, radio specific, grab-and-go package is excellent. I particularly like the top grab handle for easy carrying and stowage but wish the base had rubber feet or bars to prevent excessive fabric wear on the underside. Priced at £156.00, from me 4.8 stars. (could make a great gift item. Maybe leave your PW open at this page. Ed)
Backpack Antenna Mount
Having only seen illustrations of antennas mounted on the backpack side plate, I looked at using a car boot lip mount but found that the securing grub screws were on the underside of the plate, making reliable securing difficult. Obtaining a Q-80 boot lip, mount bracket (eBay) and by simply removing two small angle adjustment screws, then moving the
antenna base part 90°, the problem was solved. It’s a cross between a traditional Bulldog clip and a lever clamp. Its insulated, non-damaging jaws have both clamp depth and tension adjustment and the whole assembly can be easily removed.
Choice of antenna is perhaps for another time, but for VHF/UHF expect to use a lightweight, open phase coil type collinear of some sort, such as a Diamond NR-770HB, to keep the weight as low as possible. HF is only really practical by using counterpoise wires or an earth connection to the bracket and this may even be needed at VHF/UHF.
Verdict
A Problem solved. Durability of materials, springs and shiny metal remains to be seen. Will likely require some maintenance, but easily replaced at a low cost (circa £12.00).
Warning! Don’t expect any antenna to simply plug-and-play with any backpack – as you need to achieve and maintain an acceptable VSWR by experimentation.
mAT-705 Auto Tuner
The Chinese maker has been quick to market a solidly housed, compact, IC-705 specific auto-tuner, ahead of Icom’s own AH-705, due out soon.
The mAT-705 covers 1.8-54 MHz, is supplied with a 1m transceiver control lead and uses latching relays to save energy.
Power is provided by an internal 9V Alkaline battery and there is a batterylow warning LED. Unfortunately, there’s no external supply input option. Battery change is by removing four rear-panel Allen screws and carefully sliding out the main board, Standby current drain is typically 7mA and up to 31.4mA when tuning. No power handling data is given on the downloadable instructions but I would guess 20-25W to be around the maximum, looking at the relatively small relays.
A first tune cycle on any band takes around five seconds. Shifting frequency within the same band, re-tuning takes less than a second on first press of the PTT. The processor system boast 16,000 memories and impedance range is from 5 to 1500Ω.
How well it works is all about the antenna, critical for QRP operation. It worked well with loaded verticals but short wire antennas on low frequencies were, as to be expected, beyond its matching range. For 160-80m or higher impedance antenna set up, the Emtech ZM-2 is well worth a look.
The Emtech ZM-2 is available as a kit or ready built. The mAT-705 provided reasonably good results with both a doublet and also with an 8m wire using a BNC plug to twin terminal adapter. (obtained separately)
Verdict
I like the solid feel of the construction plus it’s lightweight and very portable. Although the maker states that battery lifetime is good, it’s not ideal. I wouldn’t want to change the battery in the field. Removing the rear panel as instructed, the board jammed and I was in danger of pulling the BNC wire connections from the circuit board, solved only by also removing the front panel. Now cured by silicon grease on the board edges. Priced competitively at £219.94. From me it’s 4 stars
Power
Key to successful portable activity is power availability. The IC-705 is supplied with the tried and tested 1880mAh BP272. The more costly, higher capacity 3150mAh BP307 is now separately available. It’s not bulky and clicks neatly in place, weighing only 36g more than the regular item.
Charge time is approximately 3.5 hours with the radio switched off and provides more than 65% more run time in a compact package.
Occasional users contemplating more than one battery, might like to also consider a second BP272, plus rapid desk stands charger BC-202IP2 as a possible cost-effective alternative
I dismissed the idea of carrying a heavy, sealed lead acid battery in the backpack, as I was able to easily find a suitable lightweight, alternative. I purchased a 5000mAH Li battery, commonly used in the CCTV industry. It arrived from Amazon complete with AC charger and cost
£ 45.00. I carefully removed the 2.1mm, plug, extended the fly lead, added an in-line fuse and 2.5mm right angle plug to fit the IC-705.
I sourced extra 2.5mm pro plugs and weatherproof, mini automotive blade fuses and holders from the CCTV and automotive pages of eBay to make additional power leads for home and car use. DIY leads cost me less than half those appearing online, some of which appear to have no in-line fuse protection.
Verdict
Genuine Icom batteries are excellent performers, if a little costly. You do get what you pay for, but I would suggest not to ignore possible alternatives, according to your needs. BP307 is priced at £90.00 and for that reason only, from me it’s 4 stars.
Desk Stand
Icom have now confirmed that a dedicated desk stand MBF-705 is on the way and I’m looking forward to testing it soon.
Chinese suppliers were quick to provide a machined alloy bracket with an integrated antenna socket, plus an earthing point. Simple enough to mount, while giving a choice of antenna terminations SO239 or BNC. When not in use the fixing screw stows neatly underneath the back platform.
It disappointingly didn’t quite sort out the stability problem, as expected. The viewing angle was much improved, but the
radio still tended to be unstable on smooth surfaces. Photographs often show the bracket with a sturdy Comet HFJ-350M base loaded, tapped coil whip attached. I’ve only ever seen this in the USA so I tested with a lighter weight version from my FT-817. It helped to stabilise the radio, but not fully. The heavier Comet antenna will most likely work better.
Verdict
A neat way to reduce strain on the radio’s antenna socket giving a choice of connector plus an improved earthing point, if a little ungainly. Priced between £25£35.00 according to source, from me for convenience factor it’s 4+ stars.
Z Mounts
Still seeking a desk mount solution, I tried a low-cost plastic type photographic Z mount as an experiment. It definitely gave the much-needed adjustable angle but was still prone to sliding. A heavier, professional grade, Neewar Z mount proved a much better solution. The metal alloy construction and rubber foot pads ensured that it sat firmly on the desk while providing a range of adjustment and choice of viewing angle.
Verdict
The radio is now firmly planted, it no longer falls over. The display is at last, easy to see. Priced at £25.00. From me it’s 5 stars… Result!
Conclusion
Last month I predicted that the Icom IC705 marked something of a change in commercial amateur radio equipment and operating as urban environments fill up with electrical noise. I can already see the aftermarket moving in this direction and I’m looking forward to what comes to market next.