I thought it was about time to show some of my workshop activities over the last six months. However before doing so, I think it would be appropriate to discuss why I have developed the equipment in the form I have! While I have “done it my way”, I am sure you are aware there are many ways to become active on the Amateur Radio Microwave Bands.
Initially I was going to develop my microwave activity from my home QTH however I decided that, while this would be a relatively easy task, it would not assist in any way to promote the microwave bands, within the wider Amateur Radio Community within Brisbane, which is located in the southeast corner of Queensland, Australia. My home station allows me to be QRV from 160m to 13cm and while this has been a good spread of frequencies in which to enjoy our hobby I wanted to take up the portable gauntlet and actively pursue the microwave bands from a range of portable locations. It was this decision that has tempered the development of my equipment.
Setting the Specifications
To begin with I want to develop a series of Transverters that all shared a common format. This would ensure that all of the basic components used would be able to be purchased in bulk meaning that it would force me NOT to use some obscure and not readily available object from the junk box such as connectors, meters, switches and power connectors from older equipment and or obsolete projects. I further decided to arrange the layout of external controls and connectors in a common format or a mirror thereof. In addition I decided to use common type of connectors for the power to each of the Transverters. I also standardized on the drive level for each transverter thereby over coming a potential problem by overdriving the transverter. The final decision was to feed the PTT voltage for the transverter to the centre conductor of the common IF coax to the transverter. This ensures that every time the transverter is used the IF coax is validated and of cause there is one less control cable to be provided.
With these requirements clearly set, there were four (4) other specifications that had to be established. The first requirement that was clearly etched in my mind as a direct result of operating porable over many years, was the need for the supply voltage for all of the transverters to be the same! Why, well any of you who have worked portable will know just how difficult it becomes to generate higher voltages easily and to maintain this higher voltage for long periods of time while working in some out of the way portable location. The second was the drive level for the transverters which I was determined to have set at 5 watts; Why? Because my IF Transceivers are Yaesu FT817’s with a maximum of 5 watts output thereby overcoming the fear of overdriving and destroying the transverter. Requirement number three clearly focused on the antenna and feed line and how they would be combined to each transverter. In reality the solution was obvious and was based on how would the equipment be moved and setup quickly! Since my method of transportation for all the equipment is an SUV, ther was a need for every thing to fit in or on the vehicle! The choice, tripods would be used to support the antennas with the transverter attached to the antennas.
The fifth issue was to look at how to increase the power output of any or all of the transverters should the need arise!
The following images show the finished transverters covering 1.3, 2.4, 3.4, 5.7 and 10Ghz.
In future postings I will describe what components were used.