Thanks to Amateur Radio Weekly, I came across a recent contact on the 10 GHz band that took place between the states of Tennessee and Virginia in the United States.
The video shows a successful contact on FM between N4OFA in grid EM86RS and K4LY in grid EM85WB. The distance was about 190kms or 120-miles which on FM over an obstructed path is impressive.
I looked at the path profile and it seems that the most likely mode of propagation was knife edge diffraction over the mountains in between.
It was curious to note the QSB (fading) on the signal as well. Reason? Vegetation moving? Some aircraft scatter?
In the video description, Mike N4OFA writes... "This is a video that amazed both of us, signals were very strong, I found Doug's beacon where he was portable near his house. A quick touch up with my wonderful tripod and he was hitting S9 with quick QSB. What kind of propagation is this? Doug's FM signal sometimes hits S9 on my little FT817nd. Note: no elevation on the dish at all, no rain cells between us. We did not try CW as there was no need since we could carry on a conversation even on FM."
See video below...
1 comment:
Just found this Feb. 6, 2026. I'm K4LY in EM85, SC, not VA. The path to N4OFA/p goes directly over Mount Mitchell, NC, the highest mountain east of the Mississippi, and the summit of Mount Mitchell is about half way and LOS from both ends of the path. We have been successful with this 105 mile path virtually 100% of the time, using ~30 db gain dishes at both ends. Using a 11.7 dB gain omnidirectional slot antenna at my end is also usually successful. I suspect diffraction explains the always present signals. However, there is almost always QSB, and on some days signals peak 20 dB stronger than on other days, so other types of propagation are involved. I have also operated portable and worked N4OFA/p over slightly longer paths from EM84, EM94, and EM95 when Mouth Mitchell was not LOS from my end. The EM84 and EM94 contacts were with rain scatter from my car using the slot antenna with very strong signals. My contact from EM85 was from 17 miles east of my home QTH using the dish. Another frequent contact is with W4DEX to my east over a non-LOS 100 mile path. We both operate from our home stations on hilltops. We find 2.3. 5G, and 10G propagation to be similar. The slightly longer path to N4OFA/p over the Appalachian mountains is usually stronger than the usual S2-S3 path to W4DEX, but W4DEX and I have experienced S9 enhancement a number of times.
Post a Comment