Kenwood R-2000
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As you can see the above
receiver is a Kenwood Model R-2000 which due to the vagaries
of trade names is sold under more than one brand name such as
Trio. This all-band (100KHz to 30MHz) example includes an optional
extra VHF front end which extends reception to the airband.
See
the operating manual for the R2000 |
Icom IC-R7000
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Above is a more expensive
receiver, again Japanese, an ICOM IC-R7000. This set is designed
for reception of higher frequencies than the Kenwood (25 to 2000MHz)
and is very useful for checking 433MHz radio keyfobs, a job I
did regularly for our local garage.
See
the operating manual for the R7000 |
Heathkit
SS-9000
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Above is a fine example
of a Heathkit SS-9000 amateur band transceiver, purchased by
the late G3AQY and his wife the late G4GOJ. This rig which dates
from the 1980s was said to be impossible for home construction
due to its complexity and only around 350 were made in the Heathkit
factory so is pretty rare. The matching power supply, PS-9000
is shown below. To see an
example of G3AQYs home-brew click the above picture. |
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Heathkit
HW-5400
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Above another Heathkit
transceiver. This was also made from a kit of parts which were
secreted in my suitcase on returning from a business trip to
Dallas, Texas in 1985. Building this rig was made more complicated
than it should have been because the parts had been separated
from the sets put together in a clever way to aid construction.
Nowadays an X-Ray scan of the suitcase would probably result
in an alert and empty the Heathrow arrivals hall. |
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I was away on business
for Plessey in 1985. We were bidding with Rockwell for a new
US Army Communications System and staying at the Harvey House
Hotel in Plano Texas. It was my second visit and I'd planned
to buy a Heathkit HW5400. Rather than drive into Dallas I rang
Heathkit and spoke to the manager John Mitchell who agreed for
10 dollars to deliver the transceiver kit to my hotel. I paid
something like $500 which was about 50% of the UK price. |
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I looked up John the other day and
sadly found he'd died in 2002. The worrying thing is he was born
only a few months before me. |
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Below this is a second
Heathkit having a few extra features including a matching power
supply, that was bought as a kit by G3AQY a little later than
mine. The matching power supply, HWA-5400-1 is shown below the
transceiver. |
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Trio
TS-120S
Below is a commercially built
amateur radio HF transceiver from Japan, the Trio TS-120S. Although
looking fairly similar to the Heathkit models, this transceiver
has the edge in mechanical design, general appearance and operating
experience. I think it's fairly true to say that the SS-9000
was Heathkit's last ditch attempt to woo the amateur radio market
before it went out of business in 1992. This left Japanese manufacturers
the major supplier of amateur radio equipment across the world
and enabled them to charge extremely high prices, which they
still do to this day... I must say that although these rigs look
very attractive mechanically, once you look inside the construction
leaves a lot to be desired especially in terms of maintainability. |
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This compact Trio ATU arrived
with the companion Transceiver TS-120S above.
Basically, the ATU can match
an aerial having an impedance of between 20 and 300 ohms at the
operating frequency of a transmitter having an output of 50 ohms.
This is done by using two controls, R Tune and X Tune whilst
checking the SWR to make this as close to optimum as possible.. |
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Left is the schematic for the
AT-120 and below is a simplified circuit diagram showing a Pi
network having a switchable input capacitor/coil and a variable
output capacitor together with a variable series capacitor.
The bandswitch has three sections.
The first selects a set of fixed capacitors for the selected
amateur band. The second selects the appropriate coil tapping,
and the third is used only for either straight-through operation
or tuning.
The circuit shows the band switch
in the straight-through position and, as the switch turns clockwise,
selects the 80/40/20/15 and 10m amateur bands. |
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Yaesu
FT-480R
I used this 2 metre transceiver
for many years. It was hugely expensive and let me down once,
shortly after purchase, but was repaired successfully by the
supplier in Louth. The PA module had failed and was probably
a stock fault due to a poor component as it didn't fail again
over the next 40 years. The rig came with a mounting bracket
so it could be used in one's car. I had a five-eighths whip and
later a seven-eighths whip although this was rather large and
objected to being driven around multi-storey car parks when it
used to clonk on fluorescent lights. |
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Heathkit Linear Amplifier-
HA14
This SSB linear was purchased
by my father in law, the late G3AQY, and has a matching power
supply, the HP-24 (below). It was used frequently and found to
run pretty warm so he made a fan unit on which it stood. It's
rated at 1000 Watts PEP and uses a pair of 572B
triodes (click to read the spec..a development of the 811A)
1000 watts PEP is a way of expressing
700 watts average power or 28.45dBW. In the UK the radio amateur
transmitting license has for many years specified the maximum
power permitted. Originally we were allowed to use 150 watts
DC input to the transmitting valve (or valves if used in parallel
or push pull) with an output no more than 100 watts. In other
words the efficiency of the valve and its output circuitry defined
the maximum power fed to the aerial. Now the license includes
the term 26dBW PEP. This is taken to be 400 watts PEP and equates
to 100 watts of carrier power. In other words... nothing has
changed, just terminology. Of course.. if you run this Heathkit
SSB amplifier at its maximum rated output you will be breaking
the terms of your license.. here in the UK. The answer is whisper
into the microphone.. use your normal voice you will be breaking
the law. |
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Heathkit 2m FM Transceiver
HW-2036A
Another ex-G3AQY constructed
kit; an early synthesised 2 metre transceiver using a rotary
switch for channel selection, set below to 145.500MHz. Without
the mains power supply it could be operated mobile using a 12
volt power input. |
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Read an advertisement
from 1978 for the HW-2036A |
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Toyo Dummy Load
Clearly marked and neatly covering
most of the popular amateur bands and rated at the legal UK maximum
power of 100Watts |
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Heathkit SWR Bridge HM-102
As you can see below, this SWR
bridge also performs as a power meter in two ranges.. up to 200Watts
and 2KW |
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Heathkit SWR Bridge HM-2102
This SWR bridge using much the
same was designed for the 2-meter band also performs as a power
meter in two ranges.. up to 25Watts and 250Watts |
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