Equipment for portable HF operations

Introduction (I)

The Sun is shining and you want to work outdoor, in the field, in portable HF operations. But how to move there your ham shack and antennas ? It is an impossible task. It is a scenario that most of us have experimented one or another day. Like most of us you will be quickly confronted to practical concerns, and you will rapidly conclude that you are unable to move your huge beam or vertical and sometimes your heavy and large high-end transceiver and its companion, the amplifier. So you will have to bring with you a lighter installation, easy to move and to set in the field.

We will mainly focus our attention on the antenna. Transceivers come in many models and in their portable version it is really not a problem to install it below the car radio, on the dashboard or close to the glove compartement. The antenna system is another affair as it becomes quickly huge when we desire to work in the HF bands, for example in the 40 or 20-m band.

The location and means

Before installing your equipment somewhere in the field you must answer to several questions. First, the location : in what car or place do you want to install your material, not only the transceiver and its power supply but first of all the antenna and its supporting mast ?

We will not discuss about the shack installed in a second QTH (/A) where you can have a replica of your home installation, but only about true portable installations (/P), including mobile (/M) working standalone in the field, and not remotely controlled over Internet (maybe in a next article).

Depending on your needs there are several solutions, from the Hummer, the monospace or the caravan fully equipped to the compact car that you usually drive that will temporary receive your portable installation.

The first solution can be assimilated to a mobile ham shack equipped with permanent rigs or rigs that you rarely moved. This is a typical "california style county expedition", HI!

The second solution is probably the most used, most amateurs going in the field with their usual car or pick-up for a few hours during the weekend or by a sunny day. Others apply this method to a "sport and nature" solution, I mean climbing on top of a mountain to active a peak, to name for example the "Colorado 14er Event" or have the opportunity to work in large open fields like Olafur, TF3ML in Iceland, where he can easily erect a tower mounted on a trailer.

To see : N6RC CQP Expedition - Colorado 14er Event

When radio amateurs meet adventure and sport

From left to right, from the lightest to the heaviest portable amateur stations : a neat and funny portable station taking advantage of both the performance of a 12m high (40') vertical and the extreme mobility of a smart car; a light PBX100-MK2 ground plane antenna 3.6 m high; a beam antenna set up for the US Field Day 2011, and the impressive home-made "portable" installation used by Olafur, TF3ML. Documents Beachbum, John Newton, K5QHD and TF3ML.

Hopefully, not everybody is obliged to buy a Hummer, a mobile tower or to be fan of trekking to practice a portable activity ! It is fine if you like adventure or sport but in the field, most of us don't have a national park or high summits in their neighborhood,. So let's leave these solutions to lucky hams living close to a natural park or large ranges. CQP and other heavy loaded DX-peditions deserve our attention but they are exceptions.

In usual circumstances, we have to take into account that our transceiver and accessories have to be compact and the antenna either telescopic or easy to dismantle to fit in a car or on the roof once the activity ended. For sure, if you own a trailer the transportation will be still easier.

If you consider moving abroad by plane and take profit of this trip to work on the air, the selection can extend to other constraints (weight, portability, etc). This solution will request some comments specially about antennas.

The transceiver

As we just told, the question of finding a small and light transceiver is not a problem, most manufacturers offering a large range of mobile transceivers very suited to that usage and with powers ranging from QRP to 200 W, dedicated to HF or multi-bands.

Even a mid range transceiver like the Kenwood TS-570D series can be installed in a car, as shows the picture below left. Of course its size (27x10x27 cm) and its weight (6.8 kg) are at the limit of portability but it is anyway 2 to 4 times lighter and almost 40% smaller than a desktop high-end transceiver (14 kg and 40 cm wide for Yaesu FT-1000MP, 23 kg and 43 cm wide for Icom IC-7851) !

To watch: HF communication via a remote Internet link

A Kenwood TS-480 control panel in the French Alps linked to its base installed in NY

At left, a Kenwood TS-570D installed on the daskboard of a Rabbit (Golf Mark4) and fed by the car battery. At center, an Icom IC-706MKIIG installed in a Honda Accord. This mobile comes with an extractible front panel. At right, a Kenwood TM-V71A (V/UHF) and a TS-480HX (HF+6m) with its extractible control panel installed in a Toyota Sequoia SUV. Documents LX4SKY, WA0TTN and KA5YIX.

Whether you use a small desktop transceiver or a mobile model, you will need additional cables from the battery to power the transceiver and the possible accessories. Depending on the tansceiver, wires can arrive discretly below the glove compartment or be gathered underneath the driver seat.

If you want to use two transceivers to work on HF and V/UHF, you will also need powerpole contacts or housings and a power distribution kit.

Engine shut down and working only on the car battery, such an installation support without problem 100 W PEP during a few hours. Of course an independent battery will be more secure. We will come back in the last page about the power supply.

If modern mobile transceivers like Icom IC-706MKIIG or Kenwood TS-480HX are true performers for their size and price, offering many functions including memories and filters, their only drawback is that most functions are accessible using a combination of keys, their small size doesn't allowing to add many controls on the front panel.

Note that the small IC-7000 released in 2006 and displayed below right was the first mobile transceiver using a color TFT screen. This "mini IC-756 PRO111" comes with several filtering capabilities, memories and scan options, and already counts among the best products.

Only minus point, during RX operations, the cooling fan of this mobile doesn't work. Consequently the rig gets quite hot in operation and as the mean time between failure also depends on the heat (MTBF decreases of 50% each time that the temperature increases of 10°C), it is a problem that Icom has to fix. We will not extend more longer on this selection.

To use in the field using a WiFi or cell phone: 

Listen to HF stations between 160 and 17 m, WebSDR

DX Hunter, the new amateur radio Apps for DX-enthusiats (for iPhone)

At left, the light (2.5 kg) and compact (17Wx6Hx20D cm) IC-706MKIIG (1200€ ). It is a multi-band transceiver working on HF and 6 m with 100 W, on 2 m with 50 W, and on 70 cm with 20 W. At right, the Icom IC-7000 (1500€) mobile transceiver. It is a bit lighter than IC-706 (2.3 kg) and more compact (17Wx6Hx18D cm). It is also a multi-band transceiver working on HF and 6 m with 100 W, on 2m with 50 W, and on 70 cm with 35 W. In addition it is also a general coverage receiver between 0.03-200 MHz plus 400-470 MHz. Here is the Icom IC-706MKIIG review and instruction manual, and the Icom IC-7000 review at eHam and instruction manual.

Finding a portable but sturdy mast

Let temporary aside the question of the antenna on which we will extend on the next pages. The next question concerns the antenna mast. This question interests mainly amateurs working with short HF or VHF beams that are sold without mast. Verticals are stand-alone, and are usually sold with a small tubing fixed parallel to the main tube while wire antennas (dipoles, etc) request only one or two poles a few meters long (or an anchor in elevation if the dipole is installed in inverted V). A tree, a wall, a chimney or even a fishing stick is ordinary used.

Factors to consider in selecting a mast are first the weight and windload of your antenna, then its height in operation and easiness to set up. To work in HF, for security reasons and to respect manufacturer standards, select preferably a robust mast which top element, the one connected to the boom, has a diameter close to 50 mm (2"). That means that the base element placed at ground level has to display a larger size, of about 70 mm. Of course to support a dipole weakly wired 5m up, the mast can be lighter.

To reach a height of 8 to 12 m (40'), these masts are usually telescopic, made of several individual sections, from 1.2 m (4') to 2.4 m (8') long each, to push-up manually, with a winch or electrically.

The two pictures at left show the setup of two of the smallest masts sold by Force12 in the U.S.A. The first is a pneumatic model. It is perfect to elevate automatically in 30 sec a 15 kg charge up to 8 m high in the field. Minus side it is expensive and requests 12V DC as all pneumatics. The mast displayed at left to the center, ref.LBT-827, is manual, using a winch to erect its load 8 m high. At right from the center, a closeup on the ASM telescopic mast sold by UKW-Berichte in Germany. Its structure is lighter (4.5 to 9 kg) than previous models but it can support an antenna up to 3 kg placed up to 12.5 m high or an inverted V dipole or even a wire beam. But it is too light and its top element is too narrow, displaying a diameter of only 20mm, to support HF beams, even the small Mosley TA-33-JRN for which you need a more robust structure. At right, small telescopic masts previously sold by Tonna (F9FT) are also too light (3.5-7 kg) to support heavy HF antennas. Their base is 40-45 mm diameter and their top element is only 32 mm diameter, what is ideal to support V/UHF or wire antennas.

The small telescopic mast (poles), made of aluminium or fiberglass are manual, their weight is ranging between 1-15 kg, and cost up to some hundreds euros. The smallest are cheap but can only support very light antennas also. That means that at the first gust wind, your mast could bend or even break. Check carefully specifications before buying.

Among these monopoles and light telescopic masts, name models sold by WiMo and UKW-Berichte (eshop at Stecker-shop) in Germany. Name also The Mast Company (Tmasco) and MGS in the U.S.A. These companies sell telescopic masts which segments have to be taken out or pushed up manually.

Name also heavier masts manufactured by Force12 (now JK Antennas) and The Mast Company in the U.S.A among others. Due to their weight, their exportation could increase their price from 50 to 75% (10 kg imported from the U.S.A. to Europe costs between 150-200 € +VAT and taxes).

You can also find sturdy masts to companies specialized in military and scientific equipments like Comrod in Norway and Clark Masts in United Kingdom. They sell masts for all applications, manual (using a winch or a small motor) or pneumatic, in aluminum and sometimes in composite and light material. Most models can be erected at ground level, on top or at rear of a car or a van. The price is relatively high but you have the warranty to use quality material that will not fail to support your beam under gusty wind.

At last, forget pylons (towers) to work in the field. It is without saying that due to their weight and difficulties that requires their installation (large steel tripods, fork-lift truck, etc) they are dedicated to expeditions and Field Days à la N6RC or to permanent installations.

At left, the PM6XL/1.5 mast from WiMo in Germany with its clamps (89.3€). Its overall length is 6 m with tube diameter from 40 to 20 mm., and its weight is 4 kg The taller model, PM12.8/1.9 (242.6€), is 12.8 m high, includes 8 segments with tube diameter from 70 to 35 mm for a weight of 15 kg. At center, telescopic poles manufactured by Tmastco in the U.S.A. Their overall length is ranging between 5.6m ($25) and 9.6m (115$). Their weight is between 1-3 kg. At right, MK6-HD push-up mast in fiberglass sold by MGS in the US.A.. Its overall length is 11.4 m and its weight is 8 kg. All these models, individual elements must be taken out manually.

Beam : warning

If you are interested in short HF beams for portable operations, working alone or with friends, some "shortened" antenna models can be relatively light - their weight is usually less than 10 kg - but most of these beams present some drawbacks (wingspan, fragility, etc). Until recently the weight of the "smallest" beam was close to 20 kg and requested the heaviest mast or better, a pylon to support it due the weigth of the structure made of stainless steel and thick aluminium (over 2 mm thick, tubing dia. 50 mm).

If you want to load a classic 3-element beam on top of a mast as we see a lot during Field Days, you must secure the mast with flexible or rigid guys to prevent any accident. But to support a full length beam for the 20m band for example or even a small Titanex, knowing that their weight is ranging between 8-15 kg, you need a stronger structure; either a small pneumatic mast or a sturdy telescopic model, if possible equipped with a winch, able to support a rotator and a winload of about 50 kg at 100 km/h

You can also buy a lighter pylon. For example a small aluminium or fiberglass mast made of 4 or 5 elements 2m long each, and 50 mm wide at the base. Attached to guy wires it is able to support a 3-element multi-band beam. Avoid the stainless steel mast as the overall weigth of the mast can exceed 100 kg. In most cases, a van or a trailer will be probably necessary to transport all this material. To reserve to group activities.

Three giants that amateurs do not hesitate to install temporary in the field to work in group or alone. At left, fiberglass push-up tubes sold by MGS in the U.S.A. used to support a small HF beam and its rotator. It is not too much asking friends some help to erect temporary the antenna in the field. At center, a 2-element multiband Steppir HF Yagi ($1455 +options). Thanks to an optional mechanical adjustment, it covers 20 to 6 m bands and displays a F/B from 12-22 dB depending on band. Its weight is 13.6 kg and can survive to a wind speed up to 160 km/h (100 miles). At right, JA6RGB home-made delta loop antenna cut for 7 MHz. It applies the same principle as the Delta 7B Delta loop sold by WiMo. One element performs as a dipole with the advantage to be optionally directional.

Most HF beams display a wingspan (the length of the larger element) close to 5 m at best, usually closer to 10 m long (for the 20 m band and lower). In worse cases, so-called "portable"  models (because they are light) are really cumbersome with booms measuring up to 10m long (e.g. the DF4SA's "spider beam" as well as several wire beams). Their advantage is their featherweight (DF4SA is 5 kg, Hex-beam is 3 kg).

However some beams are made of titanium - known for its resistance and lightness - or are made of light aluminium tubing (1-2 mm thick), that might be supported by ordinary telescopic masts. Some models like the ASM 70 mast from UKW-Berichte in Germany costs about 180 € Inbus-wrench and screws included. Such masts extend up to 10 m high, with elements 2 m long, just small enough to fit in your car. The ASM 70 mast offers a diameter from 70 to 45 mm. Its weight is 12 kg. Models sold by Tonna are best suited to support V/UHF antennas.

However, underline that using a beam for portable operations, even a small one, is somewhere an absurdity. Indeed, most low to mid-range beams, even shortened, are usually made of stainless steel (inox) and aluminium, and very few are light, made of titanium or fiberglass.

So, even if they can be very well assembled with quality U-bolt, hex nut and other worm clamps, most of them are heavy, cumbersome, and they will not support long times to be dismantled and remounted again and again. Worse, how will you set up an antenna exceeding 15 kg on top of a mast that weights as much ? It is already difficult to erect alone a 7 kg vertical 8 m long, so you will surely get in trouble in trying to erect alone a beam of 15 kg over a few meters high.

Think also about issues you already sometimes encounter to carry alone an aluminium ladder 8 m long which weight is about 12-15 kg. Sometimes you are at the limit of your capabilities to erect or to move it. The same for a beam. But you can succeed with one or two friends and some great accessories like a pulley or a winch.

If you work alone in the field you should have at best to dismantle elements from the boom and disjoin each element with the hope to put all them in your van, on your car hardtop or in your trailer. But do not imagine to handle elements longer than 4 meters... Worse, if long spreaders or X-hat 1 meter long are attached to these elements the situation is at risk, if not impossible to manage.

Without more convictions, forget also HF quads and similar models for portable operations, excepted if you work on the 10m band where their size is relatively small (about 2 m wide), or if want to set them up on top of a pylon with friends to celebrate a special event, during a Field Day, a JOTA, a castel expedition or an open-door.

Two-element quads remain at the limit of portability, even made of light material. Here are two examples. At left, a 2-element Cubex MK II PT-3 Cubical quad ($650). This model shows a 7-9 dBi gain and a F/B ratio between 20-30 dBd. The arms are made of fiberglass 3.9m (13ft) long with a turning radius of 3m (10.1 ft). In option it can work on WARC band too (12 and 17m). The boom and mast are in cast aluminum. Its weight is 16 kg. At centrer and right, 2-element quads (respectively cut for 20m and 17m bands) made of polycarbonate (plastic) by Light Beam Antenna & Apparatus, llc ($695). It weight is 14.1 kg and displays a F/B ratio of 18.09 dBd.

Remember that quads are usually very cumbersome, each side of the frame measuring about 5 m long for the 20m band with a boom exceeding 2.5 m long for a 2-element quad, without to forget that they are made of wires tight and fixed all around the frame ! There is few chance that you find "short" quads to work on HF, excepted Degen's BBQ (see page 3). And no more chance to place it in your car once assembled !

Then, the initial assembly can last 6 hours or more and once set up it can be hard to dismantle the quad. At last it is quasi impossible to install a 15 kg quad at 10 m high manually, without assistance (some friends or using a pneumatic system), and you need a robust mast to maintain it in windy locations or if you want to use it with a rotator.

This is thus a very difficult task without equipment to not underestimate. So I suggest you to reserve quads and other beams for permanent or long-duration installations, and group activities.