Many thanks to Steve (KV4AN) who shares the following article about his portable field radio kit which will be featured on our Field Kit Gallery page. If you would like to share your field kit with the QRPer community, read this post. 

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KV4AN’s Icom IC-705 Field Kit

by Steve (KV4AN)

A requirements-driven portable communication capability, using a modular implementation concept, was the basis for my IC-705 Field Kit.  I’ve loved portable radio operating since shortly after getting my license back in 1975.  My first portable radio was the over-the-shoulder Kenwood TR-2200A 2m FM transceiver.  There is now a happy confluence of advanced electronics technology, customer-focused radio manufacturers, radio sport groups like POTA and SOTA, and hams who want to combine outdoor adventures with their ham radio hobby.   The result is the ability to create and operate highly capable portable ham radio field kits, such as the IC-705 Field Kit that I’m going to describe in this article.

The kit consists of up to three man-packable bags: a Radio Bag, an Antenna Bag, and a Computer Bag, as shown in figure (1).  The Radio and Antenna bags must be brought to every activation, but the computer bag can be left at home if I don’t plan to use digital modes.  I can also swap out Antenna Bags, depending on what kind of antenna you need for the specific activation location and park rules, like: ability to use a ground spike, size of activation area, presence of suitable trees, primary operating bands and expected propagation conditions, and so forth.

Figure 1.  IC-705 Field Kit loaded up and ready for a park activation (click image to enlarge).

Radio Bag

The Radio Bag contains everything necessary to operate the IC-705 in the field.  It can be carried in one hand, worn over-the-should, or worn as a fanny pack.  With the load-out listed below and shown in figure (2), it weighs around 15 lbs.

[Gear links list at end of article.]

A. Icom IC-705 Transceiver.  Chosen for its “all-band”, “all-mode” capability with base station features and performance.  It’s a superb, state-of-the art radio, and a joy to operate – but, it “feels” a little delicate with the large unprotected touch screen and protruding light plastic knobs.

B. IC-705 Front Panel Cover. This was chosen to protect the delicate front panel of the IC-705.  I didn’t want one of the cages, because they add bulk and weight to a reasonably small and light weight radio.  This cover fits perfectly, doesn’t mar the radio body, and provides great impact protection when the radio is not in use.

C. Icom AH-705 Antenna Tuner. This is a good antenna tuner and matches the IC-705 (in appearance and electronic functionality) very well.  It is large compared to the Elecraft T1, but it runs off two “AA” batteries, which I really like.  The tuner uses a BNC coaxial patch cable and a 1/8” stereo patch cable for connection to the IC-705.   I don’t need to use this tuner very often as my antenna typically has a low SWR on 40 – 10 meters.

D. Icom HM-243 Speaker-Microphone. The HM-243 comes with the IC-705.  I’ve never used the speaker part of it, but the microphone has good voice reproduction.  If needed, I planned to use the speaker in place of headphones.

E. N3ZN ZN-QRP Special Iambic Keyer Paddle.  I got this marvelous quality and wonderful feeling paddle in beautiful Blaze Orange – so I feel like I’m the radio operator from a downed aircraft trying to get rescued.  The paddle is a little heavy for portable use, but at least it doesn’t move around while sending.  It uses a 1/8” stereo plug patch cable for connection to the IC-705.

F. Tactical Range Bag. This bag was chosen because the IC-705 fit perfectly in the main compartment and there were additional compartments for all the small accessories.  It also came in Army Green color.

G. Icom MBF-705 Desk Stand. Stabilizes the radio when it is on a table or in the Radio Bag and positions it for easy viewing and operating.

Figure 2. Radio Bag and Contents (click image to enlarge).

H. Icom BP-272 Standard Battery Pack. 7.4v, 1880 mAh pack that came with the radio and attaches to the back of it.  I use this as the spare battery pack.

I. Icom BP-307 High-Capacity Battery Pack. 7.2V, 3150 mAh pack that attaches to the back of the IC-705.  So far, this battery pack has been sufficient for my POTA activations.

J. Tactical Drop Pouch.  This pouch fits in the bottom of the main compartment of the Radio Bag and can hold either a Bioenno 12V, 12Ah, LiFePO4 battery or the front panel cover (used as a spacer).  The IC-705 sits on top of the Tactical Drop Pouch when in the Radio Bag, which elevates it enough that the IC-705 can be easily operated.

K. Smiley Antenna Company TRI-Band.  This is a telescoping 1/4 wave 2m and 5/8 wave 440 antenna that attaches directly to the IC-705.  It performs well with the IC-705 and fits inside the tactical bag when collapsed.  Another advantage of the telescoping whip is it can be adjusted for best SWR.

L. USB Cable.  The USB C to Micro USB cable is used to connect the IC-705 to the portable station computer to control the radio and pass audio and data.  This cable is needed, even if you connect using WiFi for rig control and audio, to send GPS NMEA format position and time data from the IC-705 to the computer.  I was told by Icom Technical Support that the cable should not be longer than 3 feet and should have an RFI Choke at each end.  The combination of the short cable, USB C connector instead of USB A, and the RFI chokes seems to help the noise problem that that the IC-705 has when a USB cable is plugged into it.  The other solution is using the RS-BA1 software.

M. Emergency HF Antenna. This is a home-brew antenna with a 24 1/2 foot radiator and 12 1/2 foot counterpoise that attaches to the AH-705 Antenna Tuner with a BNC to binding post adapter.  It is rolled up on a line winder and there is some paracord to hold up the end of the radiator.  This is a back up antenna in case something happens to the regular antenna.

N. Assorted Coaxial Adapters: BNC to SO-239, SO-239 Barrel, BNC Elbow, and BNC to binding post.

O. Tactical Pen.  A nice heavy pen for outdoors use.   Used for logging.

P. All-Weather Notebook. Weather-proof notepad for outdoor use.  Used for logging.

Q. Leatherman squirt E4: A Swiss Army-like miniature tool set with a wire stripper and screw drivers.  It is used to perform minor repairs in the field.  This tool has been discontinued by the manufacturer.

R. Gerber Recon Task Flashlight.   A rugged miniature flashlight that runs on 1 “AA battery and has different color lens.

Antenna Bag

An Antenna Bag goes on every activation.  The primary bag contains the components of the Chameleon Antenna Tactical Delta Loop (TDL) antenna.  The TDL is a versatile antenna that can be configured as a small Inverted Delta Loop or a 17 foot ground mounted vertical.  I usually use the 17 foot ground mounted vertical configuration because it takes less than five minutes to deploy, performs well, doesn’t attract much attention, and does not require a tuner for 40 through 10 meters.

The Antenna Bag itself is the Sunrise Tactical Gear, Tactical Tripod Bag Gen 2 (32 inch length).  It is exceptionally durable and holds all the components of the TDL antenna.  It can be worn across the back for easy carrying.  The Antenna Bag and all components weigh around 11 lbs.

Computer Bag

The Computer Bag goes on POTA activations when I intend to use digital modes, like FT-8.  The Computer Bag is shared by all my field kits, so in addition to the small Windows laptop and power supply needed by the IC-705, it also has a soundcard modem and cables.  The Computer Bag weighs around 10 lbs.

• HP Laptop Computer.  The station computer is an HP Stream 11, running Windows 11.

• Computer Bag.  The Computer Bag is a Condor Utility Shoulder Bag.  It has MOLLE straps on the outside for hanging equipment, like a handheld dual-band transceiver or a GPS, and pockets inside for a soundcard modem and cables.

The software installed on the portable station computer is configuration controlled to only include software used in the field.  This ensures that the limited space on the 64GB Solid State Drive (SSD) is not wasted, the software is configured and tested before going to the field, and the operator knows how to use the software.

Here is the software installed:

A. RS-BA1 Software.  The Icom RS-BA1 software is used to connect the IC-705 and portable station computer using WiFi for rig control and to pass audio.  It takes the place of the USB cable for these purposes.  It does not have the capability to exchange GPS or D-STAR data.  The only problem with this software is there is a slight burst of noise and some echo/ringing when you first transmit a digital signal.  I’ve not heard anyone complain about it, but I can hear it on the IC-705 monitor and see it on the scope display.

B. WSJT-X Software.  WSJT-X is used to send and receive weak signal digital modes, such as the popular FT-8 mode used for POTA and SOTA.

C. Winlink Express Software.  Winlink Express is a radio email client used to access the Winlink Hybrid Network.  It enables sending and receiving email and position reports by HF or VHF when in the field.

D. VARA HF and FM Software.  VARA HF and VARA FM are the software TNC/modem used to send and receive VARA when using Winlink Express.  VARA is a very effective communications mode as it is resistant to HF noise and fading and lightning fast on VHF/UHF.

E. SoundModem Software.  The UZ7HO SoundModem software is the software TNC/modem used to send and receive VHF Packet when using Winlink Express.  In my area, 75% of the VHF Winlink stations still use Packet.

F. Clock Software.  The Radio-Driven Clock software, written by Patrick Lindecker, F6CTE, is part of the MultiPSK package.  The clock software can set computer time using HF time sources, such as WWV or CHU.  It can also use the NMEA format data from the IC-705 internal GPS.  Accurate time is critical for operation of FT-8 and the other WSJT-X weak signal digital modes.    The license costs 35 Euros, but the ability to obtain accurate time in the field from multiple sources is an amazing capability.

G. HAMRS Software.  This software is used to log POTA contacts and create the ADIF upload file.

Conclusion

The primary focus for equipment selection was a requirements-driven portable communication capability.  I also wanted equipment that was easy to setup in the field and I strived to not include “just in case” gear that I don’t ever use.  While this field kit may be too bulky and heavy (at 26 lbs. for the Radio and Antenna Bags or 36 lbs for the entire kit) for a long hike to a summit for SOTA, I know it works very well for typical POTA activations where you setup at a picnic or camping area near where your vehicle is parked.   I’ve had a dozen successful POTA activations using my Icom IC-705 Field Kit this year and believe I have achieved my goal of creating a highly capable portable ham radio field kit.

Gear Links

Below are links for the gear used in the Icom IC-705 Field Kit.

[Note: All Amazon links are affiliate links that support QRPer.com at no cost to you.]

• Icom IC-705 Transceiver
• Icom IC-705/IC-905 Radio Protective Front Cover/shield
• Icom AH-705 Antenna Tuner
• N3ZN Keys
• Tactical Range Bag
• Tactical Drop Pouch
• TRI Band VHF/UHF Antenna
• USB C to Micro USB Cable
• Smith & Wesson Tactical Pen
• Rite in the Rain Weatherproof Top-Spiral Notebook
• Gerber Recon Task Flashlight
• Leatherman Squirt E4 Electricians Key Ring Tool (no longer in production)
• Tactical Delta Loop (TDL) Antenna
• Tripod Bag
• HP Stream Laptop 11 (no longer in production)
• Utility Shoulder Bag
• RS-BA1 Software
• WSJT-X Software
• Winlink Express Software
• VARA Software
• SoundModem Software
• MultiPSK and Clock Software
• HAMRS Software