Thursday 15 October 2020

47 and 76GHz DATV Expedition to IO91GI


Having previously proved out the 47 and 76GHz equipment on narrowband modes it was time to try them on DATV. Advance planning with G8GTZ and G4LDR came up with some paths to try in and around IO91GI on October 14 so an expedition was planned

I left Malvern at 0815 aiming for Combe Gibbet IO91GI25 to meet Noel. G4LDR was going to the Stockbridge site IO91GC68.  My journey took longer than expected due to road works and I arrived at 1030. 47 GHz narrowband signals were very loud on NBFM both ways and a two way DATV QSO was easily had. Moving to 76GHz. I eventually had a two way qso with Neil (after finding a field solution to the transverter sticking on transmit with no IF radio attached) and Noel received G4LDR/P but could not be received by Neil. As time was flying by and the road would have tractors on it at 1400 (the local land manager told us) we decided to go to the next site


Combe Gibbet 47 and 76 GHz


Combe Gibbet 76GHz 


G4LDR 47GHz received at Combe Gibbet


47 and 76GHz at Combe mast alongside G8GTZ 76GHz

G4LDR 76 GHz received at Combe Gibbet


Neil went to the Butser site IO90MX13 while we moved across the ridge to the Radio mast site IO91GI61. Narrowband signals were loud both ways on 47 GHz and a two way DATV qso was had thereby extending the UK 47 GHz DATV record to 51.8km.  76 GHz narrowband signals were good both ways on both mine and Noel's systems, but at this point the damp weather arrived, not good news for 76 GHz propagation. The optical path to G4LDR/P disappeared in the mist along with any hope of any DATV qsos.. It then started to rain so the attempt was abandoned at 1650. Due to rain and roadworks I got back to malvern at 1900.


G4LDR 47GHz received at the Combe Mast