VK5ZD Microwave Stuff

This 3.4GHz transverter uses a W1GHZ design shown here. The transverter board can be seen in the centre of the chassis with the four pipecap filters. The veroboard at the right-rear has the interface to the 144MHz I.F. radio, T/R switching and 8v regulator for the transverter. Right front is a Minikits local oscillator. The crystal is inside the foam with a QH40A heater from Kuhne (surplus from my 10GHz transverter after I bought the MKU-XO1-PLL). The output frequency from this board is 542.6667MHz. Centre front is the power supply for the local oscillator. To keep things as stable as possible, I decided to provide a regulated 12v supply.Since this unit runs from a 12v battery, I need to boost the voltage up so it can be regulated back to 12v. This is done using a half watt audio amplifier kit from Jaycar called 'The Champ'. The circuit was altered to be a square wave oscillator with the output being rectified and added to the nominal 12v battery supply. This gives around 17v which then goes to a LM317 regulator. To the left of the transverter board is a commercial 4 watt power amplifier which is connected to the antenna changeover relay via an isolator. On the left of the chassis is the power supply for the PA which requires a -2v bias supply and +7v at 2.5A.

This 10GHz transverter is built around the VK3XDK kit. On the right in the picture is a phased locked oscillator with an output frequency of 2,484MHz. This is referenced to a 10MHz OCXO in the centre of the chassis. The two boards supplied with the kit are mounted vertically, with the multiplier board being closest to the oscillator. I added a plate with RF absorbing foam between the two boards. I doubt that this was actually necessary but I figured it couldn't do any harm. Right front is a commercial Avantek 200mW amplifier. The strange looking device just above it is my attempt at a home brew attenuator. Centre front is the antenna changeover relay. Left front is a switch mode supply used to produce 28v for the relay and a regulated 12v for the PA. Left rear is the I.F. radio interface and T/R switching, all controlled by a PICAXE-08M chip.

This is a commercial 5.8GHz data link that has been converted to a transverter. The unit was made by a company called ioWave. Originally, it used a full duplex system with Tx and Rx frequencies 60MHz apart. The transmit site used a single mixer to convert the incoming signal on 110MHz up to the output in the 5.8GHz band. The receive side used dual conversion with a first I.F. of 170MHz and a second I.F. of 70MHz. Both local oscillators used VCOs phased locked to an internal 10MHz TCXO.

To convert it to a transverter, the processor was removed and replaced with a PICAXE-08M chip which does the T/R switching and programs the PLL for an I.F. of 144MHz. The second receive mixer was removed and the original 70MHz filter replaced with a home brew version for 144MHz.

Not visible in the photos (underneath the PCB) is a 28v power supply and antenna changeover relay.

WBFM system for 10GHz and 24GHz. An old LNB is used for the 10GHz receiver with the output being fed to a Uniden scanning receiver (not shown). The transmitter takes a signal on 425MHz from my FT-60 H/T. This is fed to a Minikits 3.4GHz multiplier which does a x8 to produce 3,400MHz. This then goes to a W1GHZ '10GHz Personal Beacon' board which outputs 10mW on 10.2GHz. The 24GHz system uses a conventional gunnplexer arrangement. The unit has a switching arrangement to connect the scanning receiver to either the LNB or gunnplexer outputs. For such a simple system it has produced surprisingly good results.