Brisbane VHF Group Inc.

Chasing 3.4GHz by VK4AFL/VK4FLR

As 1/3/2023 will be etched in the memories of a few grateful radio operators as one of the best. Here are those memories.

Trevor(VK4AFL) writes “Hello Frank – Without a doubt todays microwave contacts given the distance were the best I have ever experienced! I initially thought the rising temperature might have killed propagation before it did but eventually it was like a switch being turned off.  This was a good learning experience apart from anything else & I am now extremely confident about making  further SSB contacts [certainly Q65] under poorer conditions than we had today. There are many more challenges e.g. a winter contact, Kent etc.  John’s reception report was also very noteworthy. If however this is the one & only spectacular 3.4 Ghz contact I will ever have  details of todays effort will be inscribed on my tombstone. Very hot [30 degrees] calm with a blue sky here & 58% rh.

Frank(VK4FLR) writes”Hello Trevor , Well what a morning & day !! , what can I say ? Q65 is redundant now as 3.4 ghz band produced some  amazing signals this morning  at times with SSB up to 5/9+25db  & still going at 8am , alignment of my dish to 153 degrees made a big difference I think !!  so we have equalled the Australian record & done it on SSB, as well as Q65. Actually blown it out of the water !!  with multiple contacts this morning …I am still in shock can hardly believe what has happened , breaking some new ground here ?? 23cm was still S9++ on ssb at 8am as well  & 9cm up to 5/9+20db   there was no AC on the path at 8am & even this morning they didn’t seem to have much affect so it seems like tropo /ducting only. The sounding chart at Yeppoon shows a low inversion at 5,000ft & at BNE shows a similar one down low with a couple of minor inversions higher up , will be interesting  to see the charts they do for to-day. Temp was down to 22C with 73% RH wind was calm at 6am but currently 10knots s/e max to 30C no rain. Conditions at 9am still holding 5/9 on 23 & 9cm you were   S6 to  S9 on 9cm when you reduced power level to 10w I think you said , I checked my transverter , just a matter of unscrewing a coax feed to the amp & patching to the coax relay to go to 2/3w output ,, can try that next opening ?? Sked at 10am , 23cm just 5/2 on peaks tropo has finally shut down with the ground heated thermals , nothing heard on 9cm , see what happens to-morrow , I certainly didn’t expect it to hold up for that long amazing experience  sets the benchmark for the future re 9cm ??? whats the next challenge ???  ….go mobile & extend the record ???   go further up the bands ??, but in reality  I think I need to consolidate & complete the 9cm setup now that’s its proven itself…. 

9cm Q65 readout for the record 

203830 7 0.1 915 : VK4FLR VK4AFL QG62 q

203900 4 0.2 908 : VK4FLR VK4AFL QG62 q3

203930 7 0.2 908 : VK4FLR VK4AFL QG62 q3

204000 5 0.1 908 : VK4FLR VK4AFL R+02 q3

204030 5 0.2 908 : VK4FLR VK4AFL 73  q3


 BREAKING NEWS "NEXT M A D"is 26th May/ Many VK2/4 have given interest NSW/ NTH QLD. See u all there. Next Meeting 26th June2024  Chermside Library Confirmed/Teams  Donate your CANS/Bottles. Please contact Jason for TEAMS entry Information .