The shack in January 2012
Click the image to enlarge the photograph
MØMTJ Amateur Radio Station:
amateur radio station consists of an Icom IC-706MKIIG Transceiver with
FL-223 (1.9 kHz) and FL-232 (350 Hz) filters. The 706 is used as a home
base radio for HF, 2 metres and 70cm SSB
. Also sitting proudly on the
shelf is a Kenwood TS-590S transceiver for HF and 6 metres. For FM work
on 2 metres and 70cms I have a Yaesu FT-7900. I also have a lovely
FT-857D which I sometimes use for mobile work and 2 metres and 70cms at
home. It also has a narrow INRAD 2.0 KHz 8-pole Collins
filter installed for SSB work which improves reception on
bands - this narrow filter also helps increase the
audibility of transmitted audio under difficult conditions, when
selected for TX in the menu. http://www.inrad.net
I use the standard HM103 microphone that was supplied with the Icom IC-706mk2g which I
find perfectly good. The same goes for the MH48 microphone supplied with the
Yaesu FT-7900 which also seems perfectly adequate. The same cannot be
said for the supplied microphone that is supplied with the Kenwood TS-590.
While the audio quality of the Kenwood microphone is excellent, the
microphone casing is very 'creaky' and unless one holds it very gently,
it produces a lot of creaky noises on air. I tried tightening the case
and also placing sponge and other soft materials inside the case, but
to no avail.
I am currently using a Beyerdynamic TGV35ds cardioid
microphone which seems to get good reports, but I have also experimented
with an old Radio Shack /
Tandy Optimus 33-7058 unidirectional dynamic microphone mounted on a
goose-neck. PTT is achieved by a foot switch. More information here >
The H.F. antennas are fed via two RG213 coaxial cables into the garden
and switched in the shack for easy selection. They can be fed via either
an MFJ 945-E, LDG Z11Pro or AT200ProII Antenna Matching Unit.
The main antenna for the HF bands is an
Inverted L aerial
trapped for 40 metres and 80 metres with the addition of a 17 metre
band section and adapted for use on Top Band by the use of a switchable
loading coil so it's usable from 160m to 10 metres. This is fed by RG213 coaxial cable.
The second main H.F. antenna is a Delta
Loop. The loop is really a single band antenna cut for one wavelength
on the band of interest, however is also works as a good, cheap and easy
multi-band H.F. aerial. It is fed via a 4:1 balun via RG213 coaxial
cable and is used in two configurations; the main one using a loop of
16 metres in length, this is tuned for the 17 metre band, but offers
results 15m, 10m and even 20m.
The second form is using a 12 metre long loop of wire for the 12 metre
band. The loop antenna can be put up with the minimum of fuss and at
cost; all that's needed is some thin scrap wire, a 4:1 balun which can
be home constructed, some cheap cord and some 'dog bone' style
insulators that could also be home constructed or purchased very
cheaply. It can be supported on a single pole or hung from an existing
point or slung between two convenient trees.
Horizontal Wire Dipole:
There is also a 'home brew' 'fan' type wire dipole with its elements cut for resonance in the 10m and 6m
bands located in the loft space made from scrap loudspeaker wire.
I made a simple wire J-Pole antenna from 450 ohm Wireman ladder line and
a length of insulated wire. This was to a design by DK7ZB. It is
supported by a 10 metre fibreglass fishing pole which can be put up as
and when required. It's simple, cheap, effective and relatively stealthy
as it can be hidden away when it's not in use. I have also made wire J-Pole antennas for 6 metres and 2 metres.
Other H.F. Antennas:
I may also use a 7.2 metre high "UnTenna" supported
by a fibreglass fishing pole using a good quality G Whip
9:1 UnUn or a
GWhip End Fed Zepp. I have also used both a ground plane antenna, again supported by the fibreglass fishing
pole, cut for the 20 metre band and
a trapped dipole for 20 and 10 metres fed
by 75 ohm twin
feeder and 1:1 balun to the ATU, both with good results. However the
Inverted L and Delta Loop antennas are, for now, offering the most
versatility on H.F.
VHF & UHF Antennas:
2m & 70cms FM are taken care of by either a Watson W50 'white
band vertical collinear mounted on a push up mast in the garden or a
dual band wire N9TAX wire J-Pole antenna installed in the loft space.
SSB is catered for with a DK7ZB design dual band Yagi antenna, with 5 elements for 2 metres
and 8 elements for 70cms, mounted horizontally on the push up pole and rotated by a lightweight AR300 rotator.
Computer Data Interfaces:
external USB sound card that links the Icom transceiver to a Windows PC
for use with data modes such as CW (Morse), RTTY, PSK31, SSTV and
Kenwood TS-590S is also linked to the PC by direct USB connection which
conveniently allows data RX & TX and rig control.
I had to rebuilt the PC in January 2012: The Abit
Motherboard that I installed in August 2008 disappointingly failed
prematurely in December 2011.
Now the PC consists of a new Gigabyte
GA-M68MT-S2P AM3 ATX motherboard (with solid long life capacitors), AMD
Athlon II X2 250 3.0GHz Dual Core Processor, 2GB Corsair DDR3 1333MHz
RAM Memory and a Seagate 500GB Sata III Hard Disk Drive. The existing
components used are the original Nokia style case (from 2001), a Hiper brand HPU4S425 Silent 425
Watt PSU (from 2008), a Card Reader and a DVD Writer.
The system runs Windows XP SP3. All supplied by CCL
I have found from experience that the switch mode power supplies that
come with many of the cheaper PC cases and towers can create rather a
lot of RF noise across all bands. I have used the 'Hiper' brand of ATX
PSU's previously and found them to be fairly quiet as far as RF QRM is
I Use Ham Radio Deluxe v5.0 for logging together with eqsl for QSLing;
Digital Master 780 for data; FTBasic and FT7900 for memory management.
I also use RadioMobile for pixel plotting.
I do also have a Morse key (of
but I have yet to learn this art - though I am very keen to do so at
have a choice of several
external loudspeakers; A couple of old 'Realistic' Minimus 3.5 Tandy brand
speakers which are excellent. I use one for the Icon IC-706mk2g and the other for the Kenwood TS-590s. There is also a
little 'CRT' brand MS120 mobile speaker connected to the Yaesu FT-7900 and although it is
small it is quite clear and because it cuts out a lot of low frequency
sounds it can be very helpful in improving intelligibility in some
circumstances - it's not used full time but handy to have.
'bigger sound' I also have a large speaker, that sits on top of
the cabinet. This I made myself from a GL13 10 watt, 6 inch loudspeaker
unit and a grill that I purchased from Maplin. I housed it in an
admittedly rather roughly made wooden cabinet that I made for the
purpose. I find this loudspeaker to be very good in many circumstances,
particularly on the Icom. The Maplin GL13 unit is very sensitive and
good frequency range.
PC Monitor Bracket:
Initially I placed the PC monitor on top of the shelf unit, but that
was really too high to view comfortably. I later found a very strong
monitor bracket for sale at a very reasonable price (£11.00) made
I bolted the bracket to the side of the shelving unit that houses the
equipment. The bracket articulates very well and allows the screen to
be placed in any convenient position or angle.
Having limited space I could not accommodate a normal horizontal desk
style layout. The only scheme that would work in the limited space was
a vertical tower. I toyed with the idea of making a tall unit from
scratch, but then I saw the small, narrow book cases in a local
catalogue shop, Argos, that turned out to be just perfect for the job.
They were very cheap too, about £14.00 each if I remember
correctly, and actually very much cheaper than buying the timber and
other materials to make a unit from scratch - and certainly easier. I
bought two of these bookcases and cut one down a little to make it
shorter so that it would stand at the required height on top of the
other - a relatively straightforward task.
Photograph showing general layout, microphone & its goose-neck and the computer screen bracket by IntecBrackets
Tandy Optimus 33-7058
unidirectional dynamic microphone and home-brew adapter cable - more here >
Photograph showing computer screen bracket by IntecBrackets and the microphone and goose-neck in the background
Monitor bracket by IntecBrackets
Square IO82VO * WAB Square SO89 *
CQ Zone 14 * ITU Zone 27 * 52:35:48N 2:12:16W * 125m a.s.l.
2 Metres and 70 Centimetres Area From MØMTJ Home QTH
The predicted plots are produced assuming these factors:
2 Metres: 5 & 50 Watt transmitter power plots; 2dB feeder loss; 2dBd TX antenna
gain; TX antenna height of 7 metres a.g.l.
70 Centimetres: 50 Watts transmitter power; 3 dB feeder loss; 4dBd TX antenna gain; TX antenna height of 7 metres a.g.l.
In both cases RX antenna system is assumed to have 0dB overall gain/loss and also positioned at a height of 7 metres a.g.l.
plots are only very broad predictions - the actual area could vary
considerably due to different RX antenna height, gain, feeder losses and other
variable or unpredictable local conditions. For reference two S point dB scales are
shown below; traditionally S9 represents 50µv with each
successive S point being 6dBV lower. However many S meters are not
entirely accurate and each S point may be different, perhaps only representing 4 dB gradations:
2 Metres : 144 - 146MHz:
2 metres / 144 MHz predicted area plot from M0MTJ home QTH - 50 Watts - 175km map
2 metres / 144 MHz predicted area plot from M0MTJ home QTH - 50 Watts - 75km map
5 Watts - 2 Metres:
5 Watts : 2 metres / 144 MHz predicted area plot from M0MTJ home QTH - 175km map
5 Watts : 2 metres / 144 MHz predicted area plot from M0MTJ home QTH - 75km map
70 Centemetres : 430 - 440 MHz:
70 Centimetres/ 430MHz predicted area plot from M0MTJ home QTH - 50 Watts - 175km map
70 Centimetres / 430MHz predicted area plot from M0MTJ home QTH - 50 Watts - 75km map
Smile, you're on candid camera. M0MTJ in the shed - August 2012
Some older photographs of previous incarnations of the shack: