27-09-2016, 11:21 AM
Excellent report and info from Glenn N6GN via the 2m WSPR google groups page, regarding a tropo opening from Hawaii to mainland USA back at the start of July 2016 -
As many of you may have noticed, the last week has been an active one in regards to the Hawaii to Mainland tropo path. Although this condition seems to occur yearly, sometimes more than once, we have only recently had WSPR stations on both end ready and waiting to show the advantage of the mode compared to CW, SSB and FM that have been used previously.
The very first contact across the path was on 2m in 1957 between W6NLZ in Palos Verdes, CA and KH6UK on Oahu. Since then the path has been spanned on VHF through microwave amateur bands. To help alert everyone to activity, CW beacons on numerous bands have been added on the slopes of Mauna Loa, on the Big Island, at about 8200' ASL. As the duct that occurs generally is stronger and detected earlier at higher elevations, this has been very useful in alerting North American amateurs that something interesting is going on. The call associated with this site is KH6HME.
As we have found for WSPR activity on 2m and above, the Hepburn Tropospheric Forecast pages are very useful.
About a week ago the predictions started looking promising for an opening and this time KH6IMB in Volcan, HI at about 3700' feet was ready with 2m WSPR as were several here in California. If you have been watching the 2m data base lately you may have noticed this first spot
2016-06-30 19:10 N3IZN 144.490549 -27 0 DM13ji 100 KH6IMB BK29jk 4061 257
Unlike some of the wrong-band reports we see in the WSPR database, this one was real and the first one across the path this year. It was followed by many others, including two spots between Chris, N3IZN like this one
2016-07-01 06:44 KH6IMB 144.490491 -8 1 BK29jk 2 N3IZN DM13ji 4061 60
and one-way spots with Gary, WA6MEM, such as this
2016-07-01 03:34 WA6MEM 18.106121 -16 -1 DM03ts 50 KH6IMB BK29jk 3966 256
In this last spot there *is* a band error, it was actually on 2m, Wil, KH6IMB's, WSPR band was out of synch with his radio for a few hours and reported the wrong band.
Although the CW beacons from KH6HME were copiable on several bands for several days here in Northern California, and at N6GN, no WSPR spots resulted even though WA6M who is on a ridge with ocean horizon was transmitting. This time the best duct was south of us.
I asked Wil, KH6IMB, for a .wav file of one of the stronger spots to examine for any signs of spectral spreading. I'm interested in this because I have started on a WSPR/JT65/JT9 beacon project that may replace the CW beacon currently operating at KH6HME on 70cm. More on this as it gets closer to completion.
Attached is a screen shot (No screen shot or wav file attached here sorry). I'm also attaching a .wav file that you can decode with WSPR/WSJT-X and/or listen to on an audio device. If you listen you'll hear what a nice strong CW QSO this could have supported. Of course, the nice thing about WSPR is that it can decode down almost a factor of 1000 lower so can provide a spot well before there's any sign of other modes.
Glenn N6GN
As many of you may have noticed, the last week has been an active one in regards to the Hawaii to Mainland tropo path. Although this condition seems to occur yearly, sometimes more than once, we have only recently had WSPR stations on both end ready and waiting to show the advantage of the mode compared to CW, SSB and FM that have been used previously.
The very first contact across the path was on 2m in 1957 between W6NLZ in Palos Verdes, CA and KH6UK on Oahu. Since then the path has been spanned on VHF through microwave amateur bands. To help alert everyone to activity, CW beacons on numerous bands have been added on the slopes of Mauna Loa, on the Big Island, at about 8200' ASL. As the duct that occurs generally is stronger and detected earlier at higher elevations, this has been very useful in alerting North American amateurs that something interesting is going on. The call associated with this site is KH6HME.
As we have found for WSPR activity on 2m and above, the Hepburn Tropospheric Forecast pages are very useful.
About a week ago the predictions started looking promising for an opening and this time KH6IMB in Volcan, HI at about 3700' feet was ready with 2m WSPR as were several here in California. If you have been watching the 2m data base lately you may have noticed this first spot
2016-06-30 19:10 N3IZN 144.490549 -27 0 DM13ji 100 KH6IMB BK29jk 4061 257
Unlike some of the wrong-band reports we see in the WSPR database, this one was real and the first one across the path this year. It was followed by many others, including two spots between Chris, N3IZN like this one
2016-07-01 06:44 KH6IMB 144.490491 -8 1 BK29jk 2 N3IZN DM13ji 4061 60
and one-way spots with Gary, WA6MEM, such as this
2016-07-01 03:34 WA6MEM 18.106121 -16 -1 DM03ts 50 KH6IMB BK29jk 3966 256
In this last spot there *is* a band error, it was actually on 2m, Wil, KH6IMB's, WSPR band was out of synch with his radio for a few hours and reported the wrong band.
Although the CW beacons from KH6HME were copiable on several bands for several days here in Northern California, and at N6GN, no WSPR spots resulted even though WA6M who is on a ridge with ocean horizon was transmitting. This time the best duct was south of us.
I asked Wil, KH6IMB, for a .wav file of one of the stronger spots to examine for any signs of spectral spreading. I'm interested in this because I have started on a WSPR/JT65/JT9 beacon project that may replace the CW beacon currently operating at KH6HME on 70cm. More on this as it gets closer to completion.
Attached is a screen shot (No screen shot or wav file attached here sorry). I'm also attaching a .wav file that you can decode with WSPR/WSJT-X and/or listen to on an audio device. If you listen you'll hear what a nice strong CW QSO this could have supported. Of course, the nice thing about WSPR is that it can decode down almost a factor of 1000 lower so can provide a spot well before there's any sign of other modes.
Glenn N6GN