5/16″ SMA Spanner Mods
Doug, VK4OE, shows us some handy modifications to a 5/16″ combination spanner to make it more user friendly when dealing with SMA connectors in tight spaces.
… Read more...Microwaves
3.3 GHz FPV Cloverleaf Antenna
I was curious about how much bigger a 3.3 GHz cloverleaf antenna would be, compared to a 5.8 GHz antenna, to see if it was a viable alternative for FPV downlinks on 250 class mini quad.
So, I converted a broken 5.8 GHz Aomway to 3.3 GHz, as half the work was already done!… Read more...
2.4 GHz Shoot Out Site Recce
The idea of 2.4 GHz “shoot out” was raised with the VK4 microwavers present at the last 5.7 GHz shoot out.
Both myself and VK4EA did a site recce at the Murrenbong Scout Camp last weekend, and are happy to report there is no wifi crud to be heard, nor are the power lines any problems.… Read more...
PE1RKI 150W 23cm Power Amplifier
Looking for a 1296 MHz (23cm) Power Amplifier?
After discounting a W6PQL based kit, a PE1RKI 23cm 150W Power Amplifier was decided upon.
Like the W6PQL design, the PE1RKI (Bert Modderman) amp uses a pair of XRF-286 transistors, but comes fully assembled and tested AND worked out cheaper (Dec 2012) than stuffing around building your own.… Read more...
W.I.A VHF/UHF Field Day Results
Results for the WIA VHF/UHF Field Day Summer 2014 contest have just been released.
I was amused (it doesn’t take much) to note that the Contest Manager did not quote the number of logs received, as in recent years.
To satisfy my curiosity, the official summary published as PDF on the WIA web site, was used to determine this.… Read more...
S/E QLD Microwave Activity Day, Jul 2013
Finally!
Presenting the VK4 Microwave Activity Day video for July 2013.
Thank you to all those who shot some video – without the efforts of these people – there would be absolutely NOTHING to watch!
A special acknowledgement to Peter, VK4EA, for giving us a great look at his station.… Read more...
Microwave Antenna Mounting Schemes
Depending on the size and wind load of your antenna system, you may be able to get away with using tripods and mounting schemes intended for consumer grade video and still photography. 
At right, you’ll see an example of 2.4 GHz gridpack (1000 x 600mm) mounted on top of a Manfrotto Quick release plate, on a heavy duty Benro ball head and Benro camera tripod.… Read more...
3.4 GHz Power Amp upgrade
The dual-band 2.4/3.4 GHz transverter system currently runs a Toshiba UM2784B Power Amplifier on 3.4 GHz, nominally 8 watts output, as seen on the right, mounted on a slab of copper with a heatsink. This unit is being removed.
A larger and more powerful Toshiba UM2683B 3.4 GHz PA module was recently obtained, and to make room for this inside, the ThunderBolt GPSDO must be re-located out into it’s own box.… Read more...
DL2AM 10 GHz Power Amp
The DL2AM 10 GHz 10 Watt Power Amplifier arrived recently, and was “unboxed” today.
(Click on the pictures, to see them full-size)
Manufactured by Philipp Prinz, DL2AM, this requires;
- 12-15VDC
- 4.4A
- 125mW Drive (+21dBm)
My Kuhne 10 GHz G3 transverter provides a nominal 250mW output (+24dBm), so a 3dB in-line SMA attentuator will be required between the Kuhne and this power amplifier.… Read more...
S/E QLD 10 GHz Activity Day, Oct 2013
Brisbane 10 GHz Activity Day, October 27, 2013
Iain, VK5ZD, is operating portable from the Gold Coast, whilst other stations are operating S/E QLD.
A fun MAD (Microwave Activity Day) on 10 GHz!
… Read more...
Tech Talk: A Passion for Microwaves
Tech Talk at the Redcliffe & Districts Radio Club, September 16, 2013, “A passion for microwaves”, by Doug Friend, VK4OE.
Doug discusses some microwave history, and takes a look at how easy it is to get active on the microwave bands.… Read more...
Toshiba 3.5 GHz 20W PA
Looking for some power on the 3400 MHz ham band?
Toshiba UM2683B 3.5 GHz power amplifiers are available on eBay from AECI South, that become a plug & play solution for 3.4 GHz.
Buy it now price ~ AUD$200 (+/- exchange rate) + postage (approx.… Read more...
Video: Windfreak SynthNV
We take a look at sweeping an M2 23CM35 yagi for 1296 MHz using a Windfreak SynthNV USB powered and programmed RF Signal Generator / RF Power Detector from Windfreak Technologies LLC.
… Read more...
VK3XDK PLL – for dual-band
I was looking into using a single VK3XDK PLL Synthesizer for both my 2.4GHz and 3.4GHz transverter systems.
ie; sharing the one PLL for both bands, with appropriate switching.
To expand on the general concept…
The trick is to use the Si4133’s “RF2” VCO to generate the 1484MHz, whilst the “RF1” VCO generates the 1970MHz.… Read more...
VK3XDK PLL – fitting an Si4133D
One thing that became apparent when using a single XDK PLL board in a dual-band 2.4/3.4 GHz transverter system, is that the PLL’s limitation on producing even MHz only, necessitates using different IFs.
For 2403, (1970 LO), a 433 MHz IF is required.… Read more...
VK4GHZ Shop
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Eltek FLATPACK2 Volts Setter
$60.00 AUD
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Eltek FLATPACK2 24/48V Touchscreen Controller Kit
$145.00 AUD
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Genuine OEM Belt Clip for Anytone AT-D878UV & AT-D868UV - 3 Pack
$21.00 AUD
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YK04 Remote Control Kit
$30.00 AUD
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