[SFDXA] 160 Meters from KH1 summary

[Pete Rimmel N8PR]

Dear Top Banders,
Here is a brief description of the recent Baker Island (KH1/HK7Z) 160-meter 
operation.
Among the numerous limitations the USFWS placed on us, being only allowed on 
the island in June was the most onerous. A long way from ideal from a 
low-band point of view, but we were determined to make it work. The result 
was over 1500 QSO-s on Top Band.

Transmit Antenna and Gear:
The location of the 160 m TX antenna was close to the north-west corner of 
the island, but not as far north and clear of the land as we would have 
liked it. Also, we were not able to place our TX antenna fully in the water, 
due to the pounding surf. (Which did destroy our 80 m antenna the first 
night.) Instead, the 160 m TX antenna stood just at the high tidewater-line, 
with the metal base buried in wet sand. At low tide the antenna base was 30 
feet from the water?s edge, but fortunately the sand below the antenna was 
always saturated with salt-water. Luckily, the tide was mostly up around the 
times we were working NA on TB. We were only allowed a maximum antenna height 
of 43 feet. To meet this requirement, we designed a ?fat? 160 m vertical, 
which had three vertical wires, two of them on spreaders to make the apparent 
diameter of the vertical conductor larger. The antenna also had two 12.5 m 
top-loading wires, which sloped down at 45-degrees. The antenna had 8 
radials of various lengths, with three of them going directly into the 
salt-water. Takeoff to the west and north-west was clear over open water, 
but to the north-east (towards NA) it was over land, with a 20? high sand 
berm directly in the way. The antenna was fed via a remote-controlled 
coupler. I want to point out that even this simple, and far less than ideal, 
arrangement took a tremendous effort to build, as we had to haul the all the 
gear for the CW tent about ? mile from the boat landing, working in 100 
degree heat under the Equatorial sun. Transmitter power was around 800 W (but 
occasionally reduced 400 W to leave more generator power for the other 
bands). The radio was a K3S.

Receive Antenna: After the second night of operation we built a 60 foot long 
DHDL facing north-east. The antenna had a high-performance 
filter/pre-amplifier. After the fourth night we added a second DHDL that 
faced towards Europe.
We were expecting easy conditions for JA (who were closer) and difficult for 
NA. We got the opposite.The band would open to NA soon after our sun-set 
(around 18:00 local time) with very little noise. NA callers were initially 
weak but easy copy. Noise would start rising about two hours after sun-set. 
Fortunately, that was about the time the gray-line was reaching the East 
Coast, which brought up the signals well above the noise. Some East Coast 
signals were quite loud. As the evening progressed, noise continued rising as 
more of the equatorial thunderstorms to our west came under darkness. By the 
time the JA-s would show up (about 5 hours after our sun-set) noise was way 
up, and receiving conditions were becoming difficult. Still, some West Coast 
stations kept coming in strong, well over the noise, and quite able to work 
among the numerous JA callers. Occasionally, we had to listen up for NA above 
1825.00 to avoid the JA QRM, but on the long run that proved to be 
unnecessary. Overall, working NA was a pleasure, while working JA (and SE 
Asia) was a pain due to the noise. By midnight local time the lightning 
crashes on the TX antenna were becoming painful. Later, the DHDLRX antennas 
would help, but even then, many signals were a better copy on the TX antenna. 
Almost every call was different, some would be strong and clear on the TX 
antenna, while others could only be copied on the RX antenna. There was also 
a large variation in RX conditions from night to night. On our second night 
the noise was much higher than on the first night. Also, as we were working 
progressively weaker stations, things were getting harder.
Although we knew that the chances for working western EU were basically nil, 
we made a big effort to work as far west possible. On most mornings the noise 
was just too much to copy anything below S7. A few nights, however, 
conditions were favorable, and we got as far as European Russia. Conditions 
were the best on our last night, when just at sunrise we got as far west as 
Serbia, with numerous Russian and Ukrainian stations also logged. (Remember, 
this was in July!)
After operating 7 straight nights on 160, my ears were ready for a break. We 
switched to FT8 for about 5 hours, using the regular QSO mode (not 
hound-and-fox). With N1DG operating, we made about 120 NA QSO-s in about 5 
hours! Just before midnight, we switched back to CW for the JA-s, who are not 
allowed to operate FT8 in the lower part of the band. The FT8 operation 
revealed three things: There is serious demand for FT8on TB, the mode gets 
through the noise very well and gives modest stations a chance to work 
serious DX on TB, but it is easily dominated by the strong signals.
An interesting lesson from what happened to our 80 meter antenna. Initially, 
it stood on a sturdy metal base in the water. During the first night we had a 
storm and the surf broke up the base (snapping ?? bolts like they were 
matchsticks). The surf knocked the antenna down and soaked the tuner with 
salt-water. The next morning, we rebuilt the antenna further up the beach, 
but without the metal base which originally connected it to the salt-water 
ground. Although we added a good number of radials, performance was poor, 
especially when compared to the 160 m antenna,whose metal base was in 
contact with the salt-water below.

The key lessons learned:
1.  160 m DX is more than possible in June and July.
2. For good results, you must be on the band every night, otherwise you may 
miss that special night when the conditions line up just perfectly.
3. A salt-water ground helps,and where possible, vertical antennas should 
stand in the water. Being up the beach is not the same.
4. RX antennas are needed to work the weaker stations.
5. DXpeditions should have a station dedicated to 160 m (at night) with 
operators who want to work 160.
6. FT8 is now part of Amateur Radio, even on TB.

Happy DX-ing and 73,
George,
KH1/KH7Z (AA7JV)