Since the earlier
pages describing my test gear were compiled some years ago,
there have been considerable changes, particularly during 2004-2005.
I was fortunate to acquire a number of items of test gear for free!
These included an HP141 spectrum analyser, a Wiltron 18GHz sweeper
and an HP436 power meter. In addition I was also able to buy other
items at very cheap prices... 2004-5 must go down as by luckiest
years in microwaves!
The photo on the
right was taken in early 2004, before some of the equipment mentioned
above was obtained. It's here in my radio shack where I make most
of my microwave equipment. It's very handy to have microwave power
meters, a couple of spectrum analysers and other test equipment
within an arm's reach of any gear being constructed.
In August 2004
I was made the amazing offer of a large amount of free test
gear.This was all to have been thrown away as waste if I hadn't
taken it! Included in the offer were three HP141 18GHz spectrum
analysers, four HP 18GHz sweepers, a Wiltron 610D sweeper, four
HP microwave power meters (HP435/436 types) and sundry other items
including a spare RF and IF plug in for the HP141.
I made the 320
mile trip down South to get this gear feeling extremely fortunate!
As a result I've been able to give two of my local microwave friends
each a spectrum analyser, HP power meter and a sweeper.It seemed
as if all their Christmasses had come at once! Another friend got
an HP436 power meter!
is the centre bench of my test gear station, with from top to bottom:
Ailtech 7514 Noise Figure Indicator (PANFI), Wiltron 610D 10MHz-18GHz
sweeper, HP141T+ RF plug in for 0-18GHz spectrum analysis.In
addition I have the 0-110MHz RF plug in for the HP141T as well
as an HP mixer to allow me to "see" both 24GHz
and 47GHz on the analyser.
Noise Figure Indicator has selectable IF inputs and the facility
to inject an external Local Oscillator to create almost any IF you
want. I also have a 12GHz Ailtech Noise Head for this gear
and it seems to have a reasonably constant ENR across a wide range
from at least 1GHz to over 12GHz.
Shown on the right
is another "rack" of test gear recently acquired...
From centre top
to bottom: Farnell FG3 Function Generator,
HP436 Power Meter with matching RF head to 18GHz at
10 microwatts (to 10mW with matching 30dB inline attenuator), Racal
Dana 9916 frequency counter with homemade prescaler to approx
To the left
of the central rack can be seen, from top to bottom, some items
I've had for several years.... "Poor Man's Caesium Clock"
1MHz/10MHz TV locked frequency standard, G4COM simple noise
figure meter, 12V 10A DC bench power supply and a Marconi
12GHz variable oscillator source. On the far right is the edge
of one of my two Marconi Microwave power meters for which
I have RF heads up to 26GHz.
Shown left are,
from top to bottom, a couple of bench digital multimeters
which I bought at an amateur fleamarket in early 2005 for just £5
($8 US) for the two!
Below the DVMs
is my Thander 0-1GHz Spectrum Analyzer Adapter which I purchased
many years ago at a price that I could now buy a surplus HP141T
system for today! It has given me good service even though it's
range is limited. They appear on Ebay from time to time at around
£100 and are a cost effective way of getting a spectrum analyser
for the lower microwave region. With external mixers it's possible
to look at frequencies much higher of course. The adapter is connected
to the X and Y inputs of a Gould oscilloscope. The scope
bandwidth can be as low as 10MHz in this application. Suitable scopes
can be bought at fleamarkets for as little as £20
One corner of
my shack houses the frequency measuring and generating equipment.The
lower left side of this photo is my main frequency reference which
outputs a series of extremely accurate sources at 1MHz, 5MHz and
10MHz, in addition to 100kHz and 10kHz. Several of these outputs
are used to lock either of the two Adret 5105 synthesizers (the
identical units standing on top of the Racal synthesizer in the
lower right region of the photo) as well as the Racal and my frequency
counter. This frequency reference has been running continuously
for over 5 years. From time to time I check it against a TV locked
source but it never seems to vary in accuracy.
shown here include an old Polarad 6-11GHz signal generator,
still quite useful at times, a Pye HS4B 48MHz source, a Qualcom
1152Mhz source and a home made 96MHz source locked to
the 60kHz MSF transmissions.
Shown left is
my 1.5GHz spectrum analyser, the HP 182T/HP8555B.This instrument
is quite portable and I have taken it up to my local amateur radio
club for a demonstration.
To the left of
it are, from top to bottom, is a homemade sun noise meter (designed
by G4NNS), a logarithmic amplifier, a HP Normaliser (used
with the spectrum analyser to store traces for reference against
others in real time, and at the bottom, a Gould 2GHz sweeper.
The item on top
of the analyser is a 0-30V variable DC bench power supply.
the right is my Pacific Microwave network analyser which
I hope to get going quite soon. It has a couple of faulty switches
and I am short of some connectors for it.Once again, I was fortunate
enough to have been given this useful instrument!
To the left is
one of my two Marconi 6460/3 Microwaver Power meters with
a 100mW 12GHz head attached. These have been available on the UK
surplus market in reasonably large quantities over the past few
years but the supply of spare RF heads is getting smaller and smaller.
They are easily damaged by overload or shock from dropping them.
Today the heads alone cost more on the surplus market than the complete
power meter and head did say 10 years ago! Notice the array of coax
to waveguide transitions on the top of this power meter. I have
them up to 24GHz or so, along with a good selection of directional
couplers in both waveguide and coax. I also have a number of isolators,
in waveguide and also coaxial types. These are most useful when
measuring higher RF powerlevels than the power meter can handle.Of
course I also have msny coaxial attenuators, several good to 26GHz
and some relatively high power ones (25 to 50 watts) up to 12GHz.
You can never have too many attenuators!
are many other items of test gear in my shack(much of it home made),
including an audio oscillator, VHF and microwave wavemeters, RF "sniffer,
and so on ... the kind of items than any self-respecting radio amateur
should have available for testing his equipment. Much of it is simple
stuff that does a good job. You don't need to spend a fortune to get
reasonably well equipped to tackle most fault tracing and equipment
evaluation and alignment. Regular browsing of Ebay is an essential
if you want to get some decent test gear! Some items can be obtained
very cheaply, such as the nice little clone of a Leader signal
generator shown right...it was only £15 at a "fleamarket"
and is in pristine condition.
never been in the radio or electronics industry (I was a High School
Geography teacher for 36 years!) and therefore completely cut off
from some excellent test equipment that I know my friends "in
the business" can access, I feel fortunate that I am now reasonably
well-equipped to make most of the tests and measurements I need for
my microwave hobby.
and test gear can become an obsessive hobby in its own right!I know
folk who obtain test equipment to test other test equipment!