Brisbane VHF Group Inc.

Getting that signal generator to go further.

In search of furthering the knowledge base one of our Club members (VK4MJF), had recently visited a local Club members shack, to do some frequency checks on 5.7GHz. His signal generator Wind freak USB (low priced) would only read between 137MHz to 4400MHz had its shortcomings. They evaluated the gear bought for testing, with high quality equipment, a signal generator and a spectrum analyser. Suggesting all items they checked had the ability to work on the band required (5.7GHz), some were eliminated one being a band pass filter unable to be tuned to the required band. Ok now armed with this knowledge VK4MJF was set to return to his work bench and test on, using the local beacon supplied by the Club site at Edans landing (which to date had not been heard). Several other ideas were also discussed, one being a reflector on the tower to reflect the Club beacon signals, 10GHz, 3.4GHz etc. had been reflected leaving the tower virtually dish free. Great idea apparently used in the commercial sector to lengthen there range with a small db loss, also assisting to keep older members safely on the ground. During these discussions a suggestion about using a small schottky diode system( as a X3 Multiplier), would assist his signal generator to increase its ability to give MJF a signal on 5.7GHz. Well what a gem, …… this idea gave him the tools to use this device in lots of other unreachable bands of 10 GHZ to name one, also further. One thing that came to mind Stefan VK4CSD had given a talk on using diodes for 26, 46, 76 and 122GHz at the one of our monthly meetings, sometimes a small idea gives greater scope.

           STOP PRESS ""Beacons under repair" Currently our 2 metre and 6 metre Beacons are to be refurbished" Our Next Meeting.....Wednesday 25th September 2019  Rob's Place Edans Landing. see u there.