Practical Wireless

Practical Portable with the Icom IC-705 and Other Radios

Richard Constantin­e G3UGF goes out and about with the IC-705, reviewed last month.

- Richard Constantin­e G3UGF practicalw­ireless@warnersgro­up.co.uk

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.

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