Hi there ! Thanks for visiting my WEB site.

I have had an active interest in electronics since I was a young pup ! At the age of 12,  I built my first Crystal Set
with "liquid solder" out of a tube. My interest in most things RF eventually led to a career with Telstra (formerly
the Post Master General's Department) in 1967 and my Amateur Radio licence in the mid 1980's.  With the
passing of time & my choice to end a 30 year career with Telstra, there has been a change in direction and my
lifestyle is now a lot less stressful. Although not officially retired (I'm still just 56,  I still run my small Business - RF RESALE
and I do the "odd job"  in RF Consultancy & for something quite different Oxy & MIG Welding too when they are offered.

My rapidly growing Business of acquiring and selling surplus Microwave & RF Hardware & Used  Test
Equipment  has been "ramping up" to the point of requiring a Full time focus & dedication to servicing the
needs of a wide range of Business Clients & Amateur Radio enthusiasts.

So there you have it.

Feel free to browse around and please forward ANY comments/criticisms or questions you may have to me at this Email address.
 

AMATEUR RADIO ACTIVITIES.
 

Well now,  there are so many activities on the plate that I will only discuss a few of the most significant.

In the last 5-10 years, the major activities have been in the field of Microwave communications.  This has come about through the close association with my fellow co-conspirators in these activities - shown in the photograph below and taken at the 1997 SERG Hamfest.  Without their enthusiasm & drive,  I doubt there would be anywhere near the renewed interest in the Microwave bands that we have in VK today.

Our "build" activities were initially prompted by the "friendly" rivalry between our group in the Eastern states & those in Western Australia - VK6.  Refer below for a short list.

I guess some of the inspiration came after Wally Howse - VK6KZ in conjunction with Roger Bowman - VK5NY set  a new World Record Distance record for a terrestrial 10 Ghz contact of 1912 km across the Great Australian Bight.  Wally then moved onto his 24 Ghz (narrowband) project and in conjunction with Neil Sandford - VK6BHT (now VK2EI) they initially set and then extended the VK Distance Record to 142.7 Km's for this band in January 1998.  This National Record has since been further extended to some 231 Km's by myself and Russell - VK3ZQB.

Back here in VK3 (& VK5)...  transverters were quickly built - initially for 10 Ghz,  & almost immediately "Distance Records" were extended in several eastern states.  Then followed transverters for 3 & 5 Ghz. Most were based on the popular DB6NT designs.  Qualcomm hardware sourced from Chuck Houghton - WB6IGP was also used for 10 Ghz. Later,  I was fortunate to "find" some 24 Ghz Gunn diode Tx/Rx units at a Melbourne Hamfest.  These were quickly integrated into a couple of conventional 88-108 Mhz FM receivers by David - VK5KK and attached to 400 mm dishes.  More Distance Records were either "set or extended".  This happened initially in VK3 & VK5 and then later via a DX Expedition to VK8, VK4, VK2 & VK1 - where 19 Microwave Distance Records fell over a 3 week period.

In the time since this flurry of building & Records setting/extending, the emphasis has shifted slightly in that we are now seeking those elusive longer distance QSO's that require the benefits of "propagation" to achieve.  This has necessitated the enhancment of our transverter configurations by fitting them with High Power Amplifiers and the use of external amps thus achieving far greater EIRP's (some in the 100's of kilowatts) from our portable systems.  For our Portable activities - most of us typically have 1-2 watts on 10 Ghz,  5-20 watts on 5.7 Ghz,  up to 10 watts on 3.4 Ghz,  5-20 watts on 2.4 Ghz, & up to 20 watts on 1.3 Ghz. Unfortunately.. recent climatic conditions have not been as we would have liked. We simply have not had the propagation opportunities that we need to streeeeeech out this distance records.  

In addition to this, there are also several of us who have  BIG   TWTA's on 10 Ghz. So this means 40-50 Watts..
The plan is to integrate these into high power home QTH stations.

Currently,  I can go portable and generate 20 plus watts from a 10/11 Ghz SSPA. For home QTH I have 55 Watts from a similarly "tweaked"  BIG  NEC TWTA that started it's life on 14 Ghz.

Our 24 Ghz project is up & running with several State & National Records set & extended. Most of us run the 1 Watt Toshiba PA module for TX coupled to a 600 mm dish. 

There is a general air of expectation because of the growing interest in the construction of microwave transverters up to 24 Ghz in the VK amateur fraternity. 
However... the Gippsland Microwave Conference (GIPPSTECH) which started in 1998 is confirmation of this renewed activity. For more information on this wonderful Conference... check here !
 

Earth-Moon-Earth.  UPDATED 19/4/2005 and updated again  !!!!!!

On the DUBUS Contest weekend of April 15/16, 2005, I achieved my first 10 Ghz EME QSO ("O" Copy) with Jim Vogler - WA7CJO. Jim has a really BIG EME station and is easily heard in CW & even on SSB.  Audio samples of this SSB QSO can be found below. Since then.. I have also worked the Czech Republic Club station... OK1KIR.... "O Copy" !  There was also another station worked in France but due to my poor CW skills I got the Callsign wrong.. what a waste... 

My station in suburban Melbourne comprises the following :

- Siemens 3 metre solid dish with heavy ridging at the rear to maintain structural surface integrity,
- Qualcomm Transverter mounted in the rear hub of the dish,
- RX Pre-amp fitted directly on the RX Waveguide switch is a 2 stage amp using NE325S01 devices,
- Manual AZ/EL Actuator steering control,
- LNR/XICOM TWTA delivering 90 Watts on 10368.1 Mhz mounted behind the Dish feeding WR-75 Waveguide to,
- a homebrew WR-75 Linear to Circular launch Feed connected via 2 off WR-75 Waveguide switches,
- A small CCD camera (wide angle) mounted in front of the dish ahead of Prime Focus and a second camera (fixed zoom) is mounted on the side of the dish. These video feeds can be selected and feed a monochrome monitor in the shack,
- Moon noise detection circuitry coupled to a Boonton Power Meter.

The station is currently "hearing" 13.0 dB of Sun Noise and 1.0 dB of Moon Noise. The detection of Moon Noise is very simple process... I simply use 3 dB split of the 144 Mhz RX IF output and pass it
thru a 30 dB gain block.  This amplifier is disabled during TX sequences for obvious reasons. The Noise floor is in the order of -40 dBm or better which is well within the capabilities of the Boonton Power Meter.
I originally used a 140 Mhz SAW filter with lots of gain but found the effort was NOT needed. The far more simpler approach of amplifying the broadband RX IF is more than adequate !!

NOTE : It's an absolutely sensational sight to see the Power meter ramp up from a zero reference to FULL scale as I sweep the dish over the Sun.

My initial CW Echoes/signals were quite audible but one has to listen carefully....  Here's a "sound grab" that I recorded on my Cell Phone in the very early days of hearing my Echoes... here ! 

With the progressive improvements I've made over time... my Echoes are now much improved & very much louder.
For RX I'm using a stock standard ICOM 271A with no Audio or DSP signal processing...
For TX I'm using an ICOM 275H on low power.
My return echoes are quite loud with some obvious smearing. Signal strength is such that when sending a CW carrier or DAH's... I can see the S meter responding !

Moon Tracking software is by F1EHN. Check his Website here... http://www.f1ehn.org/

I'm VERY grateful to Doug McArthur - VK3UM for his advice and general assistance.

On May, 23, 2006.. VK3XPD worked OK1KIR on 5760.1 Mhz off the Moon. CW Signals from OK1KIR at my end were O Copy and my Report from OK1KIR was M Copy.
This contact was the first EME QSO on 5.760 Ghz between the Czech Republic and Australia. It was also a NEW World Record of some 15930 kilometres.
My TWTA had developed a recent fault & the Power Output was varying quite considerably. This is the reason for the "M" copy from the OK1KIR station...

I have also found that monitoring broadband Moon Noise on the 5.7 Ghz segment is becoming a bit difficult. My station was "hearing" about 12.0 dB of Sun Noise and almost 1.0 dB of Moon Noise. The technique I use for detecting Moon Noise on 10 Ghz was a very simple process... I simply use a 3 dB split of the 144 Mhz RX IF output and pass it thru a 30 dB gain block & feed a Power Meter.  Unfortunately this same monitoring technique is not as useful on 5.7 Ghz when compared to the very quite 10 Ghz Band... My residence is in suburban Melbourne and I've found there are many WiFi and other Data signals (terrestrial noise) within in the 300 odd Mhz Band segment of the 5700-6000 Mhz ISM Band we share. So.. as these bursts of data occur.. my Pre-Amp/IF stages sees them and it sends my Power to FULL Scale.. I'm unable to easily see the 1 dB of Moon Noise without experiencing the effects of these WiFi data bursts.. So this method of detecting Moon Noise is not all that practical for this city based EME station..  I'm therefore more reliant on the "visual" Moon however, on cloudy nights it makes it very tough to find & "hold" the Moon on the Dish !!

I'm currently off air at present while I rebuild my station.
Soon I will be bigger, better and louder.. the current LNR/Xicom TWTA will deliver about 90 watts on 10 Ghz and although the same TWTA delivers about 100 Watts on 5760 Mhz... I have recently acquired another C Band TWTA that will deliver >150 Watts.. They are single Phase units made by NEC so they are ideally suited to the 240 Volt domestic power supply.
I have actually acquired MULTIPLE of these TWTA.... If anyone is interested in purchasing one ot these units.. please Email me direct...

Cheers.

Alan - VK3XPD
 

Here are a few DIGIPIX of my early station.... it has since been modified and looks somewhat different these days.

emedishrear
emedishrear1
emedishfeed
emedishfeedccd
emeampswitch
emetransverterswitch
emecontroller
 

Here are a few Audio files of my first EME QSO with Jim - WA7CJO.
A word of caution for Dial-up Internet visitors.. these files are circa 1 Mbs EACH !

eme1 - WA7CJO calling CQ
eme2 - VK3XPD calling WA7CJO - my CW is a bit rough !!!
eme3 - WA7CJO to VK3XPD - O copy
eme4 - VK3XPD to WA7CJO - O copy, OR acknowledgement
eme5 - WA7CJO to VK3XPD - RRR acknowledgement
eme6 - WA7CJO to VK3XPD - RRR with 73's
eme7 - VK3XPD to WA7CJO - RRR and 73's

eme8 - WA7CJO to VK3XPD to WA7CJO - SSB and my CW RRR's due no Microphone plugged in.
eme9 - WA7CJO to VK3XPD - SSB response
eme12 - VK3XPD toWA7CJO to VK3XPD - SSB Call and Acknowledgement/signal report.

My co-conspirators !

In the photo below from left to right are :

Russell - VK3ZQB, the "Pirranha" from Port Fairy,
Colin - VK5DK, the "DK factor" or more recently "Mr Offset" from Mt Gambier,
Trevor - VK5NC, the "Nasty Cough" from Mt Gambier,
David, VK5KK, no nickname that "we" know of,  from Salisbury, Adelaide.
 
 

A few other notables with 3, 5, 10, 24 Ghz and "maybe"  47 Ghz Transverters !

VK3EK (nee VK3DEM) - Rob Ashlin, Bairnsdale,
VK3KAI - Peter Freeman, Churchill,
VK3WRE - Ralph Edgar, Traralgon,
VK5NY - Roger Bowman, McLaren Vale,
VK6WG - Wally Green from Albany,
VK6KZ - Wally Howse, Perth,
VK6HK - Don Graham, Perth,
VK6ZWZ - Alan Woods, Perth,
VK6ZAY - Al Edgar, Perth,
VK6AO - Cec Andrews, Perth,
VK6BHT (VK2EI) - Neil Sandford, recently moved to Port Macquarrie, NSW.
VK6TRG - Terry Grammer, Perth.