Well, after viewing Diana Eng's inspiring video
(below) I was prompted to look into what's required
and so I started compiling a list of ideas which I
noted down and have now presented on this page in
case it may help others.
Portable operations could simply be a few hours on
any hill with lightweight and minimalist equipment
such as a hand held with a separate lightweight
antenna, or a weekend away camping in a bivouac or
tent with a more comprehensive set of equipment.
Additionally a portable operator may take part in an
award scheme such as SOTA or HuMPs ('HOTA') where by
a hill is 'activated' by operating from it with the
aim of 'qualifying' it by obtaining a minimum of
four valid contacts (QSO's) so that points can be
awarded to an overall score.
Setting up an HF rig for Portable SOTA operating
by Diana Eng, KC2UHB
Here is a superb
video article made by Diana Eng KC2UHB. Diana's
video shows how to set up an Amateur Radio station
for Summits On The Air (SOTA) activating Summit
W2/NJ008. Diana was accompanied by W2VV in the
making of this excellent video.
Her video is also featured in the October issue of
the online publication Make Magazine in an article
titled 'How-To: Set up an HF portable radio while
Watch Diana's excellent video:
MAKE Magazine describes itself as the first
magazine devoted entirely to DIY technology
projects, it unites, inspires and informs a growing
community of resourceful people who undertake
amazing projects in their backyards, basements, and
garages, see http://makezine.com/
Diana Eng, KC2UHB's excellent video prompted me to
find out more about what's required for /P. So
here is a list of information that I compiled and
have presented here in case it can help others
PORTABLE EQUIPMENT Important
considerations for survival: Suitable warm
& protective clothing - waterproofs,
boots, jumpers, hat, scarf etc. Map
and Compass; GPS / Satellite Navigation; Torch;
Matches; Water & Food; First Aid Kit;
Whistle; Mobile Telephone.
capacious Back Pack, Ruck Sack, Carrying Bag or
Case. Ruck sack liner and / or rain cover.
Protective case or box for the transceiver.
A suitable Transceiver:
From as small and basic as an FM Hand Held, to a
more versatile Multi-Band Multi-Mode with SSB.
Appropriate aerials (h.f. / v.h.f. / u.h.f.);
Support poles, Masting, Telescopic fibreglass
fishing pole etc; Guy ropes and Pegs; (Para
Cord/ Nylon Cord), Cleats (e.g. Clam Cleats
Line-Loks guy runners), Ground spike;
Counterpoise wire(s), Balun or UnUn; fishing
swivels (American Snap Swivels Size 2) can be
cables; ATU; VSWR meter; Patch Leads; Adapters -
e.g. BNC to SMA, BNC to PL259, PL259 to N type
or PL259 to SMA etc.
Power: Often in the
form of a (SLAB) sealed lead acid battery or
Batteries or NiMH Battery Pack; Suitable and
safe Power Cables with PowerPole connectors.
Tools: Tools needed
for erecting aerials and adjusting aerial wires,
for example: Mallet, pliers, screwdrivers, wire
cutter, pen knife etc.
Camera with mini tripod; Foam Seat Pad or very
lightweight chair & picnic table to rest
on; Perhaps some kind of shelter - tarp
or basha / bivvy or bivouac / tent / spiked fishing
umbrella with spike (?) /car / van /
caravan / motor home etc. (N.B. Motor
vehicles cannot be used to operate
from duringSOTAorSummitsbaseaward schemes and the use of tents is
about SOTA here).
Perhaps the obvious first choice for simple
lightweight portable operation might be a handheld
transceiver. There are a great many to choose from
such as a Yaesu FT-60, VX-6, VX-7, Icom IC-E90 or
IC-T70E, Kenwood TH-F7E, Alinco DJ-C7E or, indeed,
any other 'handie'. A handheld is inexpensive,
small, lightweight and obviously easily
Handies can be single band, either 2 metres or
70cms but will often be dual band giving access to
2m and 70cm from one transceiver. A dual
band model is probably a better choice as it give
more flexibility. Some models provide the bonus of
additional bands such as 6metres or 23cms while
others offer the 4 metre band. The limitation of
handheld transceivers is that they can only
provide access to a limited number of VHF and UHF
bands, have low transmitter power, typically only
5 watts, and generally only provide FM as the mode
of transmission and so can consume batteries quite
quickly. A spare battery or batteries will almost
certainly be needed for lengthy periods of use.
For handheld transceivers a separate full size
antenna will almost certainly be required for
reasonable results as the supplied helical 'rubber
duck' antennas supplied with most hand held radios
are electrically very short and inefficient. The
Sotabeams MFD or SB270 are good examples of
lightweight designs that are easy to carry.
SSB is far more efficient, especially for DX, and
will also consume considerably less power than
when operating using FM which is a very important
consideration when operating /P in a remote
location with a limited power supply. SSB can
therefore enable the battery to last much longer.
To work SSB a multi-mode transceiver will be
required. The transceiver will also need to be
small and light enough to be carried around. Many
small multi-mode portable and mobile transceivers
will also give access to the HF bands - escaping
the QRM of a populated area!
FT-857D multi-mode, multi-band amateur radio
The most popular transceiver for portable
operations is possibly the FT-817, a QRP rig by
Yaesu. The FT-817 provides 5 watts on HF, 6m, 2m
and 70cms and has a built in battery pack. Other
mobile radios such as the Yaesu FT-857D, FT-897D
and Icom IC-706mkIIg, IC-7000 and IC-7200 are a
little larger and heavier, but are also attractive
transceivers for portable operations, bearing in
mind that they all need a separate external power
supply. All these rigs offer the HF bands plus 6m,
2m and 70cm (except the IC-7200 which misses 2m
and 70cm) and with much higher power capabilities
than the FT-817. Other H.F. rigs to consider are
the popular Elecraft K2 or KX3 or the compact
CW - If you're into Morse code most of
the radios mentioned above will work CW, but you
could also consider miniature QRP and home-brew
transceivers. If you enjoy building equipment and
are proud to operate 'home brew' radios then the
"MTR" could be just the radio you need:
Power can be supplied from the car or van battery
if working in close proximity to the vehicle, but
this might not be the best solution since there is
always the possibility of flattening the battery
and getting stranded! It's not a good idea to
flatten a car battery anyway as this can cause
damage so it's best to use a separate dedicated
S.L.A.B:For QRP operation many operators use a
compact sealed lead acid battery known as a SLAB.
Typically a SLAB will need to have a capacity of
around 7 Amp hours to 12 AH to provide enough
power for several hours work. The battery is
charged at home using a mains charger.
Yuasa produce good quality batteries while Ansmann
produce suitable sealed lead acid battery
Prolific SOTA and HEMA operator Mike, 2E0YYY, made
a very important point to me: "Never, ever, ever
run a SLAB flat. If you get down to about 11
Volts, stop transmitting. NEVER store the
battery uncharged. As soon as you finish an
activation, charge it. Even if you only use the
battery for an hour... Charge it. Slow charging
is best, anything from 300mW to 1.5Amp.
The SLAB will give you years of service, if you
follow these tips."
Battery Pack: Power could also
be derived from a pack of high capacity
rechargeable NiMH cells, as is demonstrated in the
excellent video by Diana Eng, KC2UHB that is
featured near the top of this page.
For longer or higher power use a battery with
higher capacity is needed. A standard car battery
is unsuitable for this type of use as it is not
designed to be fully discharged and re-charged
repeatedly as this type of treatment will damage
the plates of an ordinary lead acid car battery, a
'leisure battery' should be used.
Battery:Leisure Batteries are
also known as Marine or Motorhome Batteries and
are designed with thicker plates that are more
able to withstand being regularly discharged and
recharged. Such a battery may have a capacity of
around 75 to 110 AH. As with other rechargeable
batteries a leisure battery would generally be
recharged using a mains recharging system.
Cycle Battery:A true Deep
Cycle Battery is more substantial than a leisure
battery and are even more able to withstand
regular discharge and charge cycles. POLARITY:Always take car with the polarity
of power leads and connectors when using batteries
- a simple rushed mistake can be very VERY costly
indeed! 30 Amp Anderson PowerPole connections are
excellent for use in amateur radio. G0HWC has some
good information here: http://www.g0hwc.com/anderson-powerpole.html
The UK Supplier is Torberry Connectors: http://www.torberry.co.uk
When operating /P a good lightweight pole
or mast may be required to support the aerial. The
simplest tall support might be a tree, as
suggested in Diana's video (above). A lightweight
and handy alternative is a telescopic fibreglass
fishing pole of somewhere between 7 and 10 metres
in length. The top two or three sections of a
fishing will be too thin and flexible to support a
substantial aerial such as a Sotabeam or the
centre of a wire dipole so, for example, a 7m long
telescopic fishing pole will support a Sotabeam
vhf/uhf aerial at about 4m a.g.l., while a 10
metre long fishing pole will support a Sotabeam
vhf/uhf aerial at about 7m a.g.l.
The full vertical length of a 7m or 10m pole could
be used to support a single vertical wire of a 1/4
wave ground plane antenna or an end fed half wave
antenna for HF work.
Other options would include sturdier, but heavier,
aluminium or fibreglass telescopic poles or,
alternatively sectional swaged poles of either
aluminium or fibreglass that may be bought from
suppliers such as Sandpiper, Moonraker and other
well known amateur radio suppliers. These will be
strong enough to support standard type vhf and uhf
beam aerials, but will be heavy to carry.
Spiders or guy rings will also be required
together with guy ropes, cleats and pegs that are
suitable for the supports being used.
and UHF AERIALS
As usual, the accepted convention
for VHF and UHF is that vertical polarisation is
generally used for FM while horizontal
polarization is adopted for SSB working.
When working portable and 'QRP' it's especially
important to ensure that both stations are using
the same polarisation otherwise the resulting
signal losses will be very significant indeed -
typically 20dB - i.e. 1/100th of the e.r.p.
compared to using the correct polarisation. I have
seen cases where a signal that is almost
undetectable and inaudible using the incorrect
polarisation has become an easily readable S4 or
S5 when both stations have matching polarisation.
Convention for VHF and UHF
FM = Vertical
SSB = Horizontal Polarisation
Pretty much any typical 2m or 70cm aerial such as
a dipole, yagi, ZL Special or 'slim jim' or other
vertical etc could be used for portable operations
as long as the size and weight can be
accommodated. If walking, rather than driving, to
a remote location such as a hill top, then a
compact, easily dismantled and very lightweight
aerial will be appreciated - there are some
aerials that are specially designed for this
the most famous lightweight portable aerial system
is from Sotabeams - http://www.sotabeams.co.uk
- the current version is the SB270 which is a 3
element beam for 2m with 6dBd gain and 6 element
beam for 70cm with about 8dBd gain. The SB270 is
designed to be mounted on a 7m telescopic
fibreglass fishing pole at a height of 4m above
ground level. The SB270 is a superb design that is
very well engineered and produced. The SB270 is
Sotabeams also produce a simple lightweight dipole
for 2 metres called the Multi Function Dipole MFD
for when very light weight portable working is
required, without the need for a directional yagi.
It can easily fixed to a gate post with ties,
stood upright in a back pack, or used standing in
a vertical psition on the ground guyed in place
with lightweight line and guy pegs. The MFD is
also shown below.
Aerial Technology produce a huge range of
aerials, some of which are especially
suitable for portable work. Shown below is
the Sandpiper 145 / 435 Dual Band Yagi with
7.3 dBd gain on 2m and 8.9 dBd on 70cm.
are the Sandpiper Dual Band Portable and the
Dual Band Open Sleeve Dipole:
easy to erect, portable HF antenna might be a
doublet aerial, as described by the NORCAL QRP
Club. This is a simple aerial fed from an ATU
and balun via twin feeder for low loss. As
described, the Norcal Doublet is 44 feet long
i.e. 22 feet per leg. The Norcal Doublet is made
from a length of 4 conductor computer cable, but
other methods could be used. The ends could be
supported by nearby trees, and/or the
centrepiece could be supported by a lightweight
fibreglass telescopic pole.
If using a telescopic
fibreglass fishing pole to support the
centre of the aetial, fix the centre of the
doublet at the bottom of the top section, or
the bottom of the next section down for more
stability and guy the pole using light
tension so that the pole sections do not
The Norcal Doublet by Doug Hendricks KI6DS, Jim Duffey
KK6MC/5 and Dennis Foster KK5PY
Norcal HF Doublet -
Fishing swivels (American Snap Swivels) are used
on this antenna as a fixing method.
or Fan Dipole:A lightweight Link Dipole or Fan
Dipole could also be suspended with the help of
a nice telescopic fibreglass pole, or other
support, at its centre. If using a telescopic fibreglass fishing
pole fix the centre of the dipole at the bottom
of the top section, or the bottom of the next
section down for more stability and guy the pole
using light tension so that the pole sections do
not collapse. With a link dipole
the bands are selected by connecting, or
disconnecting the jumpers to lengthen or shorten the
dipole to make it resonant on a particular band. A
fan dipole has a number of dipoles arranged in a
'fan' each cut to be resonant on a different band.
Using fibreglass fishing poles (Sota Poles)again. Two 7 metre long poles can
be erected in an inverted V shape and used to
support a 20 metre delta loop which will be
useable on 20m to 10m and also adaptable for use
on the 40 metre band.
The two aerial wires used are connected directly
to a 4:1 balun which is, in turn, connected to
an ATU such as the Z-11 Pro or Z-100 via coaxial
cable. See this page which shows the W6ZO delta loop
to get for the general idea of what will be
achieved. The finished aerial will be very much
like the commercially available DMV-Pro.
Even simpler would be to use
one single post or pole as a support. A loop
consisting of a 17 metre length of thin
antenna wire, for example, will work well from
17 metres to 10 metres. My own loop is made
from an 18 metre length of wire and can work
from 30 metres to 6 metres with the lowest
VSWR of 1.9 being in the 20 metre band.
Performance will depend on height and
Feeding the loop at the top or bottom will
give horizontal polarisation, while placing
the feed point on the side will give vertical
polarisation. Ideally a loop should be fed
with balanced line back to the transceiver,
connected to a balanced line ATU or other ATU
using a 4:1 balun. Alternatively use a 4:1
balun at the antenna end and run 50 ohm coax
back to the ATU / txvr - though losses will be
greater doing it by this method if the coaxial
cable is quite long.
A loop should be really very easy to install
using a single support pole and very cheap
too! All that's needed is the supporting pole,
some cheap wire, a 4:1 balun which can be
'home brewed' and some thin cord and
Long Wire:A fibreglass telescopic fishing
pole (Sota Pole) can be used to support a long
wire, end fed, aerial. A wire that is a 3/8th
wavelength for the lowest frequency of operation
can be used as the radiator, fed against a
counterpoise wire of the same length run out
along the ground.
The aerial wire is suspended in an inverted V
attached to the pole at the bottom of the top section,
or the bottom of the next section down for more
stability and guy the pole using light tension
so that the pole sections do not collapse.
) suggest that a wire of 42 feet (approx 12.8
-14 meters) will be ideal for efficient portable
use on 40 metres and up when using most types of
A.T.U. as it presents a moderate impedance on
most bands. Sota
Beams pdf Leaflet
The complete Bandspringer antenna is available to
but at a modest price from SOTAbeams:
Copland, GM1SXX very helpfully comments:
"....There are many choices and permutations, but
in general, dipoles are centre fed at a point of
current maximum (and minimum voltage). A normal
dipole is current fed but of course can be voltage
fed instead. This is what’s done in the End Fed
Half Wave Antenna, or Fuchs aerial, where a
resonant half wave wire is fed at one end (max
voltage / min current) from an L/C tank, against a
very short counterpoise wire.
The End Fed Half Wave Antenna (EFHWA) is fed at a
voltage node via a parallel resonant circuit
against a ‘short counterpoise’, it is a favourite
of backpackers and outdoor types. It can be
considered as a half wave dipole that’s end-fed at
a voltage node rather than the current node, as is
more usual. This is a very handy arrangement for
portable QRP work."
Frank, G3YCC comments
on his website: The W3EDP needs a simple
matching unit is needed to couple the wire to the
rig and a counterpoise is required for some bands,
however there is room for experimentation. It has
been shown that different lengths or removal of
the counterpoise altogether, can improve
performance, as described in RadCom, August 1996
The Tuning capacitor in the AMU can be a 365 -
500pF broadcast type or a miniature version is OK
for QRP use.
Tuning Unit: Values for coils in the unit, based
on a 2 inch former and 16 swg wire:
3.5Mhz 21 turns ; 7.0Mhz 7 turns ; 14.0Mhz - 5
"Some folks have told me the modifications below
make the antenna something other than a W3EDP. I
can tell you that it works very well with 5
watts. Create a "bundle" of counterpoise wires,
1/4 wave length for each band you will use.
Attach the bundle to the tuner in place of the
counterpoise pictured above. Be cautious, 1/4
wave length elements can have high RF voltages
present, even at QRP power levels. I've been
able to work 160-10, including WARC bands with
this type of antenna".
Fed Dipole (OCFD) - Windom Antenna
The "Windom Antenna" was described by Loren
G. Windom W8GZ. It could be an ideal wire aerial for
use in restricted spaces for multi-band operation.
It may also be an good candidate for portable
It is a wire antenna, similar to a dipole, but
unlike a dipole or doublet which is fed at the exact
centre, a Windom or Off Centre Fed Dipole, as the
name suggests, has the feed point off center.
Current versions of the Windom have a balun at the
feed point which is fed with coaxial cable. As with
all aerials the aerial should be as high as
possible. With the feed point at between 20 and 40
feet above ground the typical claimed impedance will
be somewhere in the region of 200 Ohms so a 4:1
balun will typically be required. At greater
heights, and depending upon the exact position of
the feed point, the impedance may be higher and a
5:1 or 6:1 balun might be a better choice although
balun losses will be greater.
The point at which a Windom is fed in the original
design, which used an open wire to feed the aerial,
was 15 percent off-centre. The current designs,
which are fed with coaxial cable, are typically fed
about 33 percent off centre, so one leg is 67
percent of the total length and the other leg is 33
percent of the overall length of the aerial.
The bands that are covered depends upon the
overall length of the aerial:
11 metres long (approx) should cover 20m, 15m
and 10m and the WARC bands with a tuner.
21 metres long (approx) should cover 40m, 20m, 15m
and the 10m bands and WARC with a tuner.
41 metres long (approx) should cover 80m, 40m, 20m,
15m and 10m and WARC with a tuner.
80 metres long (approx) should cover 160m, 80m, 40m,
20m, 15m and 10m and WARC with a tuner.
Cut the aerial for the lowest band to be used. In
imperial measurements using a familiar formula:
The longer leg will be 468 divided by the frequency
and multiplied by .67 = length in feet
The shorter leg will be 468 divided by the frequency
and multiplied by .36 = length in feet
Given the fairly simple formula it should be quite
easy to make an OCFD Windom - however a Windom can
be purchased at very reasonable cost commercially,
for example from M0CVO at http://m0cvoantennas.webs.com
H.F. Vertical:A telescopic fibreglass (not
carbon fibre) fishing pole makes a great support
for a lightweight VHF or UHF aerial or a doublet
or dipole, but it can also be used to make a
very effective vertical for HF. e.g. a 10m long
fishing pole could support a vertical wire of 10
metres in length, approximately the correct
length for a resonant antenna for the 7 MHz
band. The aerial feeder would be connected to a
connection point at the base of the pole along
with a 10 metre long counterpoise run out along
the ground away from the base.
Similarly a vertical aerial for the 14 MHz band
would have a vertical radiator approximately 5.5
metres long and for the 18 MHz band the wire for
the vertical radiator would be about 3.9 metres
Maybe more ground radial wires could be used for
a more effective ground-plane.
antenna - "Untenna" ?Alternatively a non-resonant
design could be employed using a 10 metre
radiator and 10 metre counterpoise fed to the
ATU by a 9:1 unun at the aerial's base -
commercial examples are available from GWhip
Antenna Products and ProAntennas - similar to the
non resonant Comet CHA250B design. This arrangement
may not be as efficient as a resonant aerial due to
quite considerable power losses on most bands, but
at least it could get one on the air from 80m to
Martin G8JNJ, suggests that a slightly better
way to home-brew a broadband HF aerial might be
to cut a vertical aerial for about
8.5 MHz, i.e. not a resonant 1/4 wave on any
amateur band, but optimised to present a
moderate impedance on as many bands as possible.
In which case the vertical wire would be about
8.8 metres long, working against the
counterpoise, and fed to the a.t.u. via an unun
- perhaps 6:1 or 9:1 - this is all open to further
research and experimentation! See http://g8jnj.webs.com/currentprojects.htm.
G0KYA has also written a couple of interesting
pieces about using a 9:1 unun and a length of wire.
He found that a wire length of 19.8 metres offered a
good compromise for a multi band aerial. Read
G0KYA's blog here: http://g0kya.blogspot.com/search/label/antennas
Interestingly 2W0SAK of Snowdonia Radio Company
recommended an antenna wire length of 7.13 metres
with their 9:1 unun - or for better efficiency a
wire that is 19.8 metres long which would be run out
as a horizontal wire. Both the 7.12 m and 19.8 metre
lengths should cover the 80m to 10m bands.
G-Whip supply the excellent WideBander antenna that
uses a very high quality 9:1 UnUn for best
efficiency together with a 17 metre long radiator
wire, see below.
Commercially Available Portable
Wave End Fed Zepp Antennas: G-Whip single band
End Fed Zepps are resonant, mono band antennas
available for 4 6 10 12 15 17 20 and 40 metres and
employ top quality construction techniques.
Aerial Technology offer a huge range of aerials at
a very reasonable cost such as the Sandpiper
Buttie Pole or Walkabout MkII and others.
Sandpiper products are usually good value. http://www.sandpiperaerials.co.uk
Moonraker have a wide range of antennas available
that may be worth investigating. http://www.moonrakerukltd.com
Some commercially made aerials can be very
expensive indeed, but other options might include
the TW2010 from Transworld Antennas, The Sigma 5
from Force12 and aerials from SuperAntennas.
ProAntennas offer the interesting DMV-Pro and the
I-Pro (similar to the Sigma5 and TW2010), or well
known GWhip products for example. Many other
portable antenna products are available - just
check out your local ham radio emporium.
Links: I have put some links further down
this page here.
Depending on the type of HF aerial being used an ATU
may be required. LDG make some excellent automatic
ATUs that are very compact and lightweight an that
have extremely low power consumption making them
ideal for battery operated portable operation.
Examples of compact lightweight ATU's include the
LDG Z-11 ProII and LDG Z-100 Pro.
Elecraft offer the very compact T1
autotuner which measures only 5 x 3 x 1 inches.
The T1’s 7-inductor, 7-capacitor L-network provides
a wide matching range, and its re-tune time from
memory is just 1 to 2 seconds and can be used with
any 0.5-W to 20-W transceiver covering bands in the
160-6 m range. This includes kits, home-built rigs,
and commercial transceivers such as the FT-817,
IC703, Ten-Tec Argonaut, SG2020, etc. More
information from http://www.elecraft.com
MFJ also produce some very small manual ATUs that
are ideal for /P. Examples are the MFJ-901B,
MFJ-902B, MFJ-902H, MFJ-904, MFJ-904H, MFJ-941E,
Mobile Antenna Tuning Unit
BALUNS or UNUNS
Small compact antenna tuning units such as the
LDG Z11 Pro or MFJ 945E, for example, do not
have a built in 4:1 balun. Depending on the type
of aerial being used a balun (or unun) may well
be needed and so should be added to the
A resonant dipole or doublet fed with twin lead
for lightness will need a 4:1 balun at the ATU.
Alternatively a simple vertical (random length)
wire up the 7 metre tall fishing pole with a
counterpoise run along the ground could be used.
Such an aerial would then an Unun as a more
appropriate matching device.
To save having to carry both a 4:1 balun and a 4:1
unun, I decided to make a combined Balun / UnUn
unit housed in a small plastics case measuring a
mere 76mm x 50mm x 28mm. Since an Unun is merely
a balun with the PL259 socket wired in reverse
it seemed logical to make an impedance
transformer with two SO239 sockets, one wired as
a Balun for doublet antennas and the other wired
as an UnUn configuration for unbalanced antenna
As a quick test I fixed a 7.2 metre length of
wire to my fishing pole, supported vertically,
and ran out a similar length of counterpoise
wire. Connected to the Baln/Unun unit with the
coaxial feeder connected to the UnUn socket, I
could obtain an easy match using my MFJ-945E on
40m; 17m; 15m; 12m and 10 metres. Surprisingly
20 metres was a more tricky band, the best SWR
that could be obtained using the ATU was about
1.5 on this band. No doubt with a bit more
experimentation I will find a more suitable
length for the radiator wire for the, admittedly
compromised, but easy to erect antenna.
If using a twin lead fed doublet antenna then
the coaxial cable is plugged in to the other
socket so that the Balun configuration is used.
The top socket is used when using the
unit as a 4:1 Balun while the second socket,
mounted on the side of the case, and is
wired for use as a 4:1 Unun. Swap the
coaxial cable that connects to the ATU
between these two SO239 sockets depending on
the type of antenna being used. When used
with a balanced antenna the twin feeder
connects to the two binding posts (red and
green) either way around; When used with an
unbalanced antenna, such as described above,
the radiating wire connects to the red
terminal post while the counterpoise or
earth wire connects to the green terminal.
The materials used suggest that the unit
should handle >100 watts which should be
ample for portable low power use of perhaps
around 10 watts to 50 watts. Read more
- FEEDER - CABLE
Ensure that the necessary feeders and cables are
available along with any adapters that will be
needed such as BNC to SMA, BNC to PL259, PL250 to
N type or PL259 to SMA etc. The necessary power cables and
PowerPole connectors or adapters.
Small 'home brew' A5 Clip Board for
portable log book using lightweight plastic
made my 'home brew' clip board from an off cut
of thin but strong plastic modellers board -
it's slightly larger than A5 size to make
writing at the bottom of the page easier. The
log sheets are A4 folded in half to make them A5
size, with the (blue) headings repeated half way
down the sheet. The transparent plastic cover is
simply a standard A4 plastic wallet which helps
protect the paper from the elements and is held
in place by a couple of small 'Bulldog' clips.
Pencils are better when its damp.
Clock or Watch - preferably digital set to UTC /
capacious Backpack, Daypack, Rucksack.
Rucksack liner for water protection. This can also
be used to store things in while the backpack is
used to hold the transceiver to protect it from
the elements - or vise versa.
Rain cover for backpack / rucksack.
Protective (lightweight) case for transceiver -
lightweight aluminium or small strong plastic
storage box that can be lined with protective foam
for padding. Headphones - use headphones so as to not disturb
nearby people who want to enjoy peace &
Morse Key for CW.
Straps; Hook & Loop Tape; Nylon Cord / Para
Cord; Cleats such as Clam Cleats Line-Lok guy runners; Small
Spike, Counterpoise wires as necessary. Perhaps
a VSWR / Power Meter if the a.t.u. does not have
one. Balun or UnUn as necessary; Fishing swivels
(American Snap Swivels Size 2) can be useful.
Foam Seat Pad for comfort.
Small ground sheet.
Tools needed for erecting aerials and
adjusting aerial wires making or repairing
cables for example: Mallet, Pliers,
Screwdrivers, wire cutter, pen knife etc.
Other things: Camera with mini tripod;
Very lightweight camping chair & picnic
table to rest on; Perhaps some kind of
shelter - tarp or basha / bivvy or bivouac /
tent / spiked fishing umbrella (?) /car / van / caravan
/ motor home etc. (N.B. Vehicles cannot
be used to operate from during SOTA
award schemes and the use of tents is
discouraged. More about SOTA
here). Don't Forget:Suitable warm
& protective clothing - waterproofs,
boots, jumpers, hat, scarf etc. Map
Compass; GPS / Satellite Navigation; Torch;
Matches; Water & Food; First Aid Kit; Whistle;
Humps Excluding Marilyns Awards (HEMA) -
Summitsbase Awards. HuMPS =
Hundred Metre Prominence. Therefore
qualifying hills must have
at least a 100 metre prominence but must not
be SOTA Summits (i.e. not
("HOTA, Humps On The Air")