KC4/ W1MRQ

 

Directive Systems is proud to have had some small part in providing Ernie Grey, W1MRQ, the required horsepower to achieve EME success from the harsh winter environment of Antarctica. The 2005 system consisted of a quad array of Directive Systems short DPM144-5LVA rear mount yagis. Ernie's size constraints at the McMurdo Base in Antarctica dictated what type of antenna was feasible. Another factor was the intense weather that blows through there on occasion. Just imagine winds so strong that they can rip out a massive garage door and fill a room with windblown snow in a matter of seconds. These doors are not the ones you buy down at the mall either! The temperatures are so cold, that LMR-400 will snap like a candy cane if flexed. The antenna had to be rugged enough to withstand these forces at work. Antarctica is not known for warm soft breezes.

Here is a picture of W1MRQ installing the 144 MHz quad array on a tower leg of the ham station Rohn 55 short tower. This was accomplished in late Summer of 2005, soon after Ernie arrived on station.

Ernie is credited with the idea of pulling this whole thing off. He has been an operator on 1296 for the K1WHS contest effort, and, over the last few years, has provided much help while building his own station capabilities on many bands up thru 10 GHz. His formal trade is as a machinist, and his handiwork shows that influence. When Ernie stated his goal to activate Antarctica on 144 MHz EME, we all jumped on the idea and put together a manageable system for Ernie to bring to the "ice". Helpers included K1CA, N2CEI, WA1T, K1DY, and K1WHS. Our hats are off to Ernie, W1MRQ, for putting it all together and making it work to provide a healthy dose of excitement to the band this DX season. (Its always DX season, right?)

 

The 2006 array shown being assembled indoors in the heavy equipment shop (see photo above) before they attempted it outdoors. (BTW, you can get a good look at the door that was ripped out during a winter storm in 2004.) Ernie, W1MRQ, is the handsome guy in the photo. These antennas have a very wide aperture, and the completed stacking system is quite large when considering the small windloading and boomlength of the individual yagis.

Ernie & Co. assembling the framework and power divider (2005)

What is that stuff that is supporting the antenna frame? It must be a special Antarctica rated lubricant! Above is a shot of Ernie & Co. assembling the whole system prior to hauling it outdoors. A four way power divider and special phase matched LMR-400 cables interconnect the four yagis into the system. A short run of 7/8" Heliax(tm) routes the signal into the ham shack when all is completed.

 

Here is a shot of the more or less completed 2005 array bolted to the tower, and Ernie posing amidst all of those finely tuned elements. I am not sure, but I think the young sport on the right is getting ready to test and see if his tongue will stick to the tower leg. Note the beautiful mountain range in the background. McMurdo Station is also located close to Mt. Erebrus, (12,444 FT, 3794 M) one of the higher mountains in Antarctica and an active volcano as well. The highest mountain there is the Vinson Massif in the Ellsworth Range at 16,863 ft. Maybe Ernie will do a grid expedition there in the future, and provide the needed grid to all of the grid hunters on 144 MHz. (NOT!) This array has been replaced by the system shown below.

The new array for the 2006 DX season! 4 X DS144-6RS yagis stacked for best gain. It gets installed on the "Stairway to Heaven". Note there is a real elevation mechanism as well as an azimuth rotor installed. An interesting assembly technique is required in Antarctica. The LMR-400 phasing lines must be heated up quite a bit and then quickly brought outside and installed one at a time, and secured in place. Failure to follow those directions will result in the cable cracking and breaking in the extreme cold. The temperatures in this picture were mild, about -25 degrees F.

Ernie, W1MRQ, outstanding in his field. Great job, Ernie! The new antenna will provide at least 2 dB more forward gain. The question of ground gain is always a sticky problem in Antarctica. Being on an ice flow is not the same as being on solid ground. Some areas around the antenna are largely ice. Ground gain effects may be difficult to predict, but the location of the antenna at the height that it is, insures a pretty good lobe at a convenient elevation angle for eme success.The 2005 season was a success. 2006 promises to be even better!

The KC4/W1MRQ Ham Station

The complete 144 EME station located in the ham shack at McMurdo Base. The rig consists of an FT-847 on 144.118 MHz, with a West Mountain Radio Rig Blaster contributed by K1CA. The PA is a new TE Systems 200 watt amplifier. As we mentioned before, the antennas are Directive Systems DS144-6RS antennas and phasing harnesses. So far Ernie has had many successes with small eme stations. The JT65 mode is working very well, and we believe that Ernie has not had this much excitement in a long time. According to Ernie, the array picks up the larger EME stations without JT65! Smaller stations with two yagis are workable via the digital route, and most failures are attributed to oversleeping or schedule mixups or changes. Stay tuned for more news from the bottom of the world. In the meantime, we are installing velcro on the ceiling here so Ernie will have a good place to adhere to and feel at home when he returns to the USA next September.

As of late April, 2006, Ernie is back in KC4 at McMurdo Sound, armed with a new array of DS144-6RS yagis installed, and a new frame and cabling for even better performance in 2006. The antennas are slightly longer (8 ft) and are built for gain and pattern at 144 MHz. We estimate an additional 2 dB of system gain with the new antennas. The original plan for QRO this year did not happen. There was just too much construction time involved and no time for testing the new 8874 amplifier, so rather than bring an unknown, W1MRQ settled on a 200 watt solid state PA. Ernie hopes that the added gain and small power increase wil help his contact totals by a wide margin. 2 dB antenna gain translates to 4 dB on the EME circuit! He should be hard at work upgrading the system as his time on the ice permits. We are all looking forward to more good things happening from the bottom of the world! As the weather moderates here in the Northern climes, remember that it is getting worse in Antarctica. (Just right for antenna work!)