Forwarding this for Will Jensby, W0EOM, W0EOM@aol.com Congratulations to all involved. ------------------- On Friday, March 1, we completed several QSOs that we believe set a new North American record on 47 GHz and a new world record on 75 GHz. At 12:30pm PST W0EOM completed a QSO from Mt. St. Helena California (CM88QQ) to KF6KVG on Mt. Umunhum (CM97AE) on 47.040 GHz. Signal levels were 20+ db out of the noise. Several minutes later W0EOM and AD6FP both completed QSOs from Mt. St. Helena to KF6KVG on Mt. Umunhum on 75.600 GHz. Once again signal levels were 20+ db out of the noise. The grid to grid distance from CM88QQ to CM97AE is calculated as 176.75 Km. After several false starts in arranging a record attempt Will W0EOM finally got everyone to agree to go out on Friday March 1. Will and Gary AD6FP went to Mt. St. Helena, Bob KF6KVG went to Mt. Umunhum and Lars AA6IW was in Los Altos Hills. Previous tests indicated we might have difficulty with paths longer than 160 Km on 75 GHz so Lars was positioned 156 Km from the Mt. St. Helena end. Arriving at Mt. St. Helena Will and Gary found the traditional operating spot in disarray. High winds the previous evening had caused a tower to fall partially destroying the wooden deck that is usually used by the local microwave crowd. The winds were also still pretty high, estimated at 35 to 40 mph. After some exploration we were able to find a sheltered spot out of the wind and set up the radios. A quick try of the 10 GHz radio resulted in nothing heard from the local beacon or Lars high power transmitter so we concluded the transverter had failed. We were hoping to use the 10 GHz signals to determine bearings to Mt. Umunum so when the radio failed things were looking dismal. Luckily Will was able to find the signal from Bob on 47 GHz with a bit of panning of the dish. Once peaked up on 47 GHz we had a good optical target to use to sight the 75 GHz dishes. The 47 GHz signal levels were sufficient to allow Bob to complete the exchange using NBFM rather than CW. After aligning the 75 GHz dishes on the same heading as the 47 GHz dish the 75 GHz signal from Bob was quickly located on the Mt. St. Helena end. To our surprise the 75 GHz signal level was as good as the 47 GHz level. The two 75 GHz contacts were quickly completed from both W0EOM and AD6FP to KF6KVG. The 75 GHz signal from Mt. Umunhum peaked 23 db out of the noise with 6-8 db fades. After working Bob on 75 GHz Will and Gary repositioned their dishes and worked Lars AA6IW on 75 GHz at 156 Km distance (this would have previously been a 1 km increase in the 75 GHz world record). Signal levels from Lars on the 156 km path were comparable but slightly less than the levels from Bob on a 176 km path. The equipment used at each station is as follows: W0EOM 47 GHz: 60 mw xmit power, 2' cassegrain dish, 4db NF rcv. 76 GHz: 8 mw xmit power, 18" cassegrain dish, 15 db NF rcv. KF6KVG 47 GHz: >20 dbm xmit power, 2' prime focus dish, 4db NF rcv. 76 GHz: 10 mw xmit power, 1' prime focus dish, 15 db NF rcv. AD6FP 76 GHz: 4 mw xmit power, 3' cassegrain dish, 15 db NF rcv. AA6IW 76 GHz: 4 mw xmit power, 18" cassegrain dish, 15 db NF rcv. All the radios use LOs that are locked to either precision OCXOs or Rubidiums. Weather conditions were very favorable for mm-wave propagation: 18% to 26% rel. humidity along the path. 40 to 65 degree F temperatures On the way down Mt. St. Helena we could easily see the snow capped peaks of the Sierras over 150 miles away. The unusually low humdity as well as the clear atmospheric conditions were major factors in making QSOs on this record path. - Will W0EOM - Bob KF6KVG - Gary AD6FP