Tuesday, 30 June 2015


I notice that the long distance records for terrestrial QSO's on 2.3 and 3.4GHz were recently broken. The records were set by veteran VHFer N6NB, Wayne Overbeck and W6IT, Greg Campbell. N6NB was operating portable in Hawaii while W6IT was operating Wayne's home station near Orange, California. Both contacts were on SSB. In Overbeck's own words as posted on the Tropo Ducting Reports reflector:

I'd like to post something about my trip to Hawaii for the current tropo duct. This trip has really turned out well so far.

Last week the Hepburn forecast suggested that a duct might form in a few days. So I bought an airline ticket and packed a station for
all bands from 144 MHz through 10 GHz in two large suitcases plus a roll-aboard and a backpack (total weight: 150 pounds). When I got here, I rented a small SUV and built a station in/on it. I made several trips to Home Depot for parts to build a rotating roof platform.

When the duct began on Tuesday, I drove all over Mauna Loa while listening to my own 222.030 MHz beacon in Orange County, Calif. It was a thrill just to hear it 2,500 miles away. By Thursday, the duct seemed to be at its best. Greg, W6IT, activated my hilltop station near Orange, CA and we worked Thursday night on six bands, including 2304 and 3456 MHz, both for new world DX records. I heard Greg well on two more bands, 902 and 5.7 GHz, but so far local QRN in Orange County has prevented him from hearing me on those
two additional bands. Let's hope the duct continues for a little longer so we can try again and also work more stations on the west coast.

I intend to write at least a conference paper and create a PowerPoint show about what I've seen and heard in Hawaii. I've noticed that the KH6HME beacon site, as good as it is, sometimes seems to be above the cloud layer that forms the top of the duct. Thursday night it was about 2,000 feet above the cloud tops. Seeing that, I drove down to 5,200' elevation to work Greg on all those bands. (The beacon site is about 8,200 feet above sea level.) My 222 beacon was definitely louder at lower elevations than at the beacon
site at that time. Friday night I operated at 7,300', which was near the cloud tops and where my beacon seemed loudest then. The size and elevation of the duct seems to vary a lot, perhaps explaining the way the KH6HME beacons vary in relative signal strength, with 432 being a louder at certain times while the 144 beacon is louder at other times. There are some very interesting natural phenomena at work here.

If anyone would like to watch a video of the record-setting 2304 QSO with W6IT, it's online on my website:
www.n6nb.com/2304rcrd.mp4 Thanks to Greg, W6IT, for his able operating on the other end of these QSOs.

73, Wayne, N6NB/KH6

With the present extremely hot stable weather on the west coast, chatter on the PNWVHF reflector suggested that operators on the coast as far up as Washington state should be watchful of any possible DX opportunities should a suitable ducting pattern form between KH6 and the coast.

The difficult and rare path between Washington state and Hawaii has been worked in the past ... lastly in 1995, when some alert '7's' found themselves in KH6HME's logbook. Paul, K7CW and Merle, W7YOZ described an exciting day from Washington state:

I'll never forget that event. On June 30, 1995, KH6HME was worked by two guys in the Aberdeen, Washington area on 2m. The next day, July 1, I drove my pickup down to the area and went to a place suggested by one of the guys (this place now has the Langley Hill weather radar installation). I had a partial contact with KH6HME, but he got my call wrong and I couldn't easily reposition my antenna as it was fixed on the vehicle, and we couldn't complete. I sat back and listened to the other guys make contact with Paul. Dejected, I drove back home. Next day, July 2, though, I got my reward. Six meters opened to Japan in a nighttime sporadic E opening. I had my first QSO with a JA. It was with a JA6 in the far southwest of Japan. And I subsequently had 150 more QSOs with JA stations during that opening. I worked all 10 JA call districts, qualifying for the AJD award. My rig was running 80 watts and my antenna was a home brew 5-element yagi about 15 feet above the ground. This was a huge opening and there have been very few like it since.

So, after the big 2m tropo event, switch to 6m for another biggie.

73, Paul K7CW

Indeed an unforgettable time. W7FI first worked KH6HME, then phoned me and I got out of bed and heard WM7A (K7NQ) working him and then I worked him followed by N7MWV after I called and got him out of bed. K7CAI had a partial but was at the edge of the duct and Paul could never quite get Ozzie's quirky phonetics " K7 Cowboys And Indians" - a lesson for me to always use standard phonetics. KH6HME was S7 and over with his 60 Watts at my Kirkland, WA QTH for nearly an hour - long enough for me to call KK7B in MI and got him out of bed to listen over the phone. Paul's QSL along with that of WA4CQG in AL who I worked on 2 Meter double hop E's on another unforgettable evening in 1988 occupy a prime spot in my Ham Shack

Then the JA's on 6 the following evening was almost too much to believe. 

Merle W7YOZ

Although the KH6HME VHF/ UHF beacons are still in operation, sadly, there appears to be no VHFers able to visit the beacon site and work the mainland, should an opening occur. Fred, KH7Y, the most recent beacon caretaker, has since moved back to California, leaving a giant hole in the VHF scene on the big island. I wonder if there is a replacement capable of activating the station?

Even without any operators at the far end, it would be exciting to just hear the VHF beacon(s) in this region. The 2m beacon, now on 144.277MHz, has even been heard here in BC, by Mike, VE7SKA, listening from his hilltop location on SaltSpring Island. Unfortunately no two-way contact was established at the time. Tropo of any kind is a rare event east of Vancouver Island's west coast because of the mountainous terrain.

One of the best ways to follow the formation of favorable conditions is to watch the tropo prediction maps on Bill Hepburn's website as well as the visible west coast weather patterns available here.

An interesting summary of the 1995 openings, as well as the associated weather pattern pictures, makes for fascinating reading on the PNWVHF Society's website, A Brief History of the KH6 Duct Into The Pacific Northwest.

1 comment:

Anonymous said...

ah yes I remember that evening in 1995 quite well - I got a partial contact with KH6HME on 144 but he couldn't get my call correct so i bailed out to give someone with more power/antennas a chance. And yes.. the 144 beacon has been heard here at CN88 several times. I've also heard this a number of times out at Tofino & had some VERY weak FM broadcast signals only when the yagi was pointed at KH6 - however no IDs of even enough audio to determine what I was hearing. However, the frequencies with signal all matched 100 kW FM signals from various KH6 mountain tops

Bill Hepburn's tropo maps for this coming weekend also show a possibility of tropo enhancement towards Alaska & I will be monitoring FM broadcast for activity from that direction. System here: Magnum Dynalab FT 101E FM broadcast monitor 76-108 mHz, stacked 10 el FM yagis @ 28' & 40', Magnum Sleuth 30dB receive pre-amp/30 db attenuator/tunable bandpass.

73 Mike VE7SKA