(also being marketed by Lowe as the SRX-100, pictured below)

Year            Introduced 1997
Power           12 volt DC (mains power included).
Size            18.5 x 19 x 6.5 cm
Weight          1800 grams
Price           œ160 including VAT in UK. 550 Guilders in The Netherlands.
Coverage        30 kHz - 30 MHz
Value           Rating * * *

Full Review

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This review was compiled with the assistance of the World Radio TV
Handbook, Amsterdam. Radio Netherlands has no financial connection with
the WRTH, nor with AKD, the manufacturer of this receiver. A slightly
shorter version of this review was broadcast in Media Network on May 15
th, 1997.
------------------------------------------------------------------------

Introduction

The top end of the short-wave receiver market has slowed in the last
twelve months. Sets costing over US$1000 have been particularly hit,
partly because many of the cheaper portable receivers have introduced a
lot of new features which attract more general users, especially those
experimenting with international radio listening for the first time.

In Britain, one manufacturer has taken a different approach. AKD, a
company based at Stevenage in Hertfordshire has come on the market with
what they call the Target HF3 communications receiver, priced at £160
sterling, including VAT. Bearing in mind that entry level communications
receivers such as the Lowe HF-150 costs £419 in it basic version, or the
Yaesu FRG-100 for around £470, the AKD is clearly very much cheaper. Now
that the units are in production, we have been testing one for the last
8 weeks, doing quite a bit of both practical listening as well as usual
standard measuring scheme.

Construction

The first thing that strikes you as you unpack the radio is that it is
extremely compact. That's partly because the 12 volt power supply is not
inside the set, but comes as a brick-style power pack which you plug
into the wall. You plug the jack into the back of the radio, connect an
external antenna, and the radio is ready to perform.

The front panel is extremely simple. There's a large liquid crystal
display showing the frequency, four little pushbuttons, two rotary
controls, one marked volume, the other marked clarify, and a large
tuning knob. In fact the tuning system is extremely simple and handy to
operate. The tuning knob has a weight inside so it has a nice feel to
it.
The coverage is from 30 kHz to 30 MHz in one kHz steps. If you turn the
knob slowly then you move in one kHz steps. If you turn it faster, then
the steps get progressively larger -- 10, 100 or even 1000 kHz -- at a
time. So if you need to, you can hop from one end of the band to the
other in a very short time. One kHz steps is fine for most broadcast
applications, but if you're going to use the set for listening to
utility stations, then the ´clarifier´ control allows you to tune finer
than 1 kHz. However, these slightly changes in frequency are not
reflected on the Liquid Crystal Display. The receiver is dual
conversion. The first intermediate frequency is at 45 MHz, the second at
455 kHz.

Modes

You can use the set for listening to broadcast stations in AM, or switch
the mode to either USB or LSB. You'll need that if you want to monitor
traffic on the amateur radio bands. The HF3 has just one memory channel,
which also remembers the mode. When you switch the set on, this is the
channel that is recalled. If you tune around a bit, you can go back to
this channel again by pressing the recall button. But that's it.

We tested a version which has a built-in board to allow you to connect
up a home computer for decoding weather-facsimile signals. That's quite
neat, but it means that on this version you have to forfeit the output
for a pair of headphones. It is present on the standard version. That's
something you can live with. But we were surprised that in an effort to
keep the price down, AKD has used an ordinary hi-fi phono cinch plug for
an aerial socket. You find this type of plug on the back of audio
equipment, but not on radio receivers.

We don't understand why AKD didn't use a conventional SO-239 socket
which is much stronger. Most ready made antennas come with a plug that
matches, so it’s a shame that you have to solder on a phone plug
instead. This is mechanically, probably the weakest point of the
receiver and within a few days of use it had worked loose on our test
example.

AKD does supply a length of 10 metres of wire with a phono plug already
soldered onto one end. But this is not the best solution for short-wave
listening. If you put the antenna up inside the average house, it is
almost guaranteed to pick up a lot of unwanted noise from apparatus
inside the house, such as fluorescent lights, thermostats, computers and
TV's. We used an external antenna with a Magnetic Balun, mounted 5
metres away from the building, with a coaxial cable feeding the signal
into the shack. The background noise was considerably quieter this way.
We also experimented with an active antenna mounted outside, well away
from the house.

The radio is very well constructed. If you look inside the HF3, you'll
find that it is logically laid out and built to last. The PLL
synthesiser is shielded inside a separate box to keep the noise away
from the sensitive input circuitry. But the outer casing is made of
durable plastic which is not shielded.
So now to some of the receivers specifications, starting with
sensitivity across the range between 30 and 30,000 kHz. We were
measuring the point for 10 dB signal to noise at 60% modulation, which
is equivalent to an AM station that is just intelligible. In practice,
20 dB signal to noise was needed for acceptable listening, using the 6
kHz filter. Between 50 kHz and 15 MHz, the sensitivity is quite
constant, hovering around 2.5 microVolts. Above 15 MHz, the sensitivity
drops, so that you need between 3.5 - 4.5 microVolts to get the same
level of intelligibility. In the SSB modes, the receiver is roughly
three times more sensitive, which is to be expected.

Those figures for sensitivity are only fair, but remember that below 10
MHz, a receiver doesn't have to be too sensitive. In this region, the
antenna will provide more than sufficient signal to drive the radio.
Above 15 MHz, the fair sensitivity of the set is noticeable, especially
if you live in low signal strength areas like the West Coast of North
America or in the Pacific

The designers of the HF3 have done this to reduce the problems of
overloading. Remember that a huge number of signals are presented to the
front end of the receiver, and the task of any radio is to pick out the
wanted signal and reject the rest. The more sensitive you make a radio,
the more you have to invest in circuitry to ensure that strong signals
don't overload the front end of the radio. Once this happens, weak
stations disappear into the background noise, suppressed by local
powerhouse broadcasters using 500 kW or more.

Attenuator difficult to access

There is a two-position attenuator on the back of the radio. If you
switch it on, signals are attenuated by a factor of 4, in other words by
12 dB. That's quite coarse, and operation is complicated by the fact
that the attenuator is on the back of the radio. If you can pick up a
fine step attenuator at a ham radio store, you'll find that being able
to try something like 6, 12, or 18 dB of attenuation is quite handy. In
practice, you're trying to find the balance between letting too little
signal into the receiver and too much.

The signal strength metre is in the form of a bar graph on the liquid
crystal display and in fact is only a rough guide to signal strength.
There are 10 segments, one of which is always lit. We found it was
easier to use your ears than use the tuning metre as a guide.

The receiver has two bandwidth filters installed. For AM broadcast use,
the best results are obtained with the 6 kHz filter. We would have
chosen a slightly narrower filter for AM use, since shortwave stations
are spaced 5 kHz apart in practice. This results in sideband splatter if
you´re listening to a weak station that is 5 kHz away from a strong
station. For SSB and facsimile, a 3.8 kHz filter is installed, but you
cannot use this for the AM mode. The selectivity of both filters turns
out to be quite good, especially for a set of this price category.
Limited dynamic range

The selectivity of the HF3 is contrasted by the limited dynamic range of
the receiver. The budget design of the HF3 shows through here. In single
sideband, two signals, each of 1.3 milliVolts and spaced 50 kHz apart,
produce a 1 microvolt intermodulation spurious product. This unwanted
signal gives 10 dB signal to noise ratio and can thus disturb reception
of a desired signal. These figures are equivalent to a third order
intercept point of -9 dBm.

The limited dynamic range is also a problem with AM broadcast reception.
To give an example. The receiver is tuned to a station of moderate
strength (6 Signals stronger than 50 dB than the desired signal start to
overload the receiver. So in practical terms the dynamic range of the
HF3 is only 55 dB, 72 dB in SSB. Any reasonable antenna is capable of
providing sufficient signal to overload the radio, especially here in
Europe, after dark, on bands below 10 MHz. In AM, we measured a third
order intercept point of around. That's about the same sort of results
we measured on the Kenwood R-600 ten years ago.

AKD have put a decent audio amplifier inside the HF3. It sounds quite
pleasant. It delivers half a watt RMS into a loudspeaker, with less than
1% distortion, which is more than sufficient for more listening
purposes. Remember that only the standard model has an output for
headphones.

If you plan to use to set for unattended monitoring, try to pick a place
with a fairly constant temperature. We found that at a stable room
temperature our example wandered about plus or minus 30 Hz during a
listening period of a few hours. That's not a problem with AM reception,
but it’s a bit more critical for telex reception. If you use the set in
an outside shack where temperatures are more variable, then the receiver
wanders by as much as 200/300 Hz over a period of few hours.

The Bottom Line

In conclusion, we did quite a bit of listening with this receiver.
During the day, using a good 15 metre long external antenna, we found
the set pleasant to use. It was great for general broadcast reception
and was able to decipher at least some of the stronger amateur radio
transmissions on 40 and 20 metres. In the evening though, listening
around 14 MHz, we had severe problems with broadcast interference from
15 and 11 MHz. Attenuation helped a bit, but not that much.

The bottom line is that this set is a great entry level receiver for the
short-wave broadcast listener. You get what you pay for. If you pay
three times the price for a communications receiver, you will get
noticeably better results. Remember too that some of the portable sets
like the Grundig Satelliet 700 will give similar, if not better
short-wave performance and they have FM reception and more memories. On
the other hand, the HF3 from AKD in the UK is easier to tune, well built
and sounds better than many portables. It fulfils a need in the European
market place.

In the UK, the set costs 160 pounds including VAT. Outside the UK, the
set is more expensive, costing around 550 Guilders here in The
Netherlands. That's of course because of import duty and transportation
costs. The HF3 is made by AKD, Unit 5, Parsons Green Estate, Boulton
Road, Stevenage, Hertfordshire, SG1 4QG, UK. AKD can also be contacted
by fax. The number is 44 for the UK, then 1438 357591.

The Lowe-badged version -- the SRX-100 -- is sold in overseas markets
where AKD does not have any presence.