April 1998
April 1998
The Rutherford Appleton Laboratory was the venue for the latest RSGB Microwave Round Table gathering on 26 April 1998. A large group of UK (and some Continental) microwavers attended the meeting. Most of them would have been very happy to have the RAL dish shown above resited in their own backyards!
The following photos show some of the activities of the day. To view them in larger format just click on each thumbnail. Click your web browser's back arrow to return to this page.
Activities included a "Bring and Buy" (or swap) session that
went on all day as the background to a lecture and discussion programme. 
G4ASR
(in the blue shirt) always comes along with a wide range of microwave surplus
to "excite" the rest of us! This year he had some surplus PLL oscillator
"bricks" and 4GHz downconverters and several other items.
Neil, G4BRK, is seen here using some of RAL's fine test gear
to assess the performance of him homebuilt 24GHz ssb/cw transverter.
Test equipment included noise analyser and a spectrum analyser that enabled measurements up to and including the 47GHz band.
Meetings
such as these are always remembered for the interchange of ideas and information
during informal chats such as that shown here. Pictured from left
to right are: Andy, G4MAP, Paul, G8AYY and Roy, G3FYX. All three have equipment
up to 24GHz while Roy is also active on 47GHz wideband. He is a keen beacon
builder.
Tim,
G3KEU, shown here talking to Simon, G3LQR and Mark, G4PCS (a member of
the G4LIP contest team), is a keen constructor of home built microwave
gear. He makes his own microstrip pc board and milled boxes and is active
on 1.2GHz, 5.7GHz and 10GHz.
Simon, G3LQR, is a very active operator on all microwave bands from 1.2GHz to 47GHz and has made many "firsts" on these bands.
The two lectures were highly informative and entertaining. Shown
here are some of the 
high
precision (and very expensive) sub millimetre wave receiving heads developed
at the R.A Laboratories and described in his lecture, Detecting Millimetre
Waves, by Brian Ellison. Brian is a leading expect in
the upper GHz region (ie in the several hundred GHz region!). The modules
shown contain semiconductors so small that they cannot be seen with the
naked eye... a scanning electron miscroscope is required! The UK pound
sterling coin (middle right) gives some idea of the size of these modules.
Receivers at these extramel high frequencies are used to scan such things
as the upper atmosphere to check on chlorine levels in the ozone layer
as well as acting as metal and weapon detectors at security check points.
This modules can see right through your clothing! The Intermediate frequency
of these RX "front ends" is often in the order of tens of GHz....
The other lecture, DSP Techniques, was by Andy, G4JNT, who is one of the UK's leading DSP adherents. His operations range from the 73kHz and 136kHz band up to 10GHz ssb/cw. He has successfully applied DSP techniques to weak signal reception on these bands. Andy is presently the Chairman of the RSGB Microwave Committee and a member of the G4RFR contest group.
The day finished off with an Open Technical Forum, chaired by Lehane, G8KMH.
Thanks must go to G3NAQ, GW4LXO and G0MJW for the organisation of the event and to Brian, Andy and Lehane for the lectures and discussion session....
