QRV on 23cm

I got the 23cm transverter from SG LAB last year, but did not find the time yet to get it to work, that is, it produces a 2W signal on a spectrum analyser and you can control it with a handheld radio, the next thing are the antenna and the mast.


In Friederichshafen I found a biquad antenna for the 23cm band, the maker provided unfortunately no mounting options, so I constructed a frame from PVC tubing to support it, drilled a few holes in the reflector (you can easily do this, it does not really hurt the SWR) and attach it with tie-wraps to the PVC frame. A single bracket mounts it to the mast, currently I apply Plasti-Dip (TM) everywhere where I suspect water can enter the cable or the antenna, it is by far the easiest method to make things somewhat weatherproof.


The mast can’t support a rotor (probably), one lightweight antenna and a long-wire for HF can do the job, if that needs to be changed then I probably need to move the antenna to the roof on a shorter steel mast etc.


The transverter itself is rather simple to operate, put it in VOX mode, set the jumpers for the correct repeater shift and off you go. Both input and output LEDs should turn green, the input LED indicates the input power and the output LED the reflected power from the antenna. If the second LED is not correct then start debugging the cable, connectors and antenna with a VNA. You can oftentimes tune the SWR (assuming that the second LED is orange but you want to have it green) by adding a short cable segment. Otherwise find a directional coupler and divert the reflected power to a dummy load.

Future for amateur use

For many years there is the claim of 1278.750 MHz for the E6 precise positioning service of Galileo. For this they need a wide bandwidth but it is a spread spectrum technique. So it remains to be seen what happens when Galileo (the European GPS) goes into full operational mode, and how the amateur band can be maintained. Also it is good to watch announcements on temporal frequency restrictions for higher frequency bands. Occasionally there are events in Rotterdam during which you can not use certain frequency segments above 1 GHz.

Last update: 15-Aug-2019 15:10