K3LR의 무시무시한 안테나와 무선국

[HL2UOK]

Amateur Radio Superstation - K3LR

I recently had an opportunity to visit the station of Tim Duffy, K3LR of West Middlesex, PA. Tim has been a ham since 1972 and in 1987 he bought an 11 acre, 1860's farm property and immediately started setting up his dream station. Today, 27 years later, it has become that and much more. Simply stated, the K3LR station is one of the number one Multi/Multi contest DX stations on the planet. Tim engineered and built the entire station and its massive 11 acre antenna farm of 13 towers, including its Yagi's, directional arrays, and switching systems that give it capabilities that are seldom seen in the amateur world.



The photo above shows a partial picture of the layout. The operating positions are in the basement of the old farm house (the white building) and nearly every antenna is fed with 1 5/8 inch hardline in uninterrupted runs that span as much as 1500 feet from the antennas to the shack. Why hard line? Although very expensive new, most of the line Tim used was obtained used as surplus from cellular or two way antenna companies at a fraction of its original cost. The towers are also from cellular and broadcast surplus sales.

One of Tim's crown jewels is the 20 meter stacked Yagi array. Situated on one of the tall towers, it includes 4 full sized, custom designed 20 meter Yagi's that Tim built himself. Spaced exactly one wavelength apart on the tower, they can be operated either individually or in various phased combinations. Each antenna has its own separate ring rotator. When all 4 are fed in phase and pointed towards Europe, signal reports are 5/9+ on a bad day . With a total of 24 elements in phase, the array sounds like a 1500 watt linear, even when running only 100 watts.

Tim has multiple Yagi's on all bands from 40 through 6 meters however most of his favorite and challenging operating is done on the lower bands with vertical arrays.



Looking up from the ground you get an idea of just how much is going on up there. this could be the 40 meter tower, or perhaps the 20, I couldn't keep track of them all.



This is the base of one of the towers showing all of the switching and control circuits.


This picture shows how the scale of the tower distorts your perspective. At the very top is a full sized, 102 foot, 80 meter dipole. Below that is a 20 meter monoband Yagi. It's worth noting that all of the antennas are monobanders and that there are multiple choices for every band. SWR is never a problem as each antenna is specifically tuned to provide less than 1.2:1 across the design operating band.


At first glance, this looks like a tower that is under construction. What it is, however, is a full sized 160M vertical Yagi antenna. The center tower is the radiator (driven element) and it is surrounded by 4 vertical "T" wires that can be switched in and out to provide reflectors and directors in 4 directions.


This picture was altered to highlight the vertical T-wires of the 160 meter vertical Yagi. Note the shorting relay boxes at the base of each wire, used to direct the beam.


Base of the 160M vertical. Note the clear insulators below the supports, and the 1 5/8 Hardline feed. The radial system is also quite massive and uses over 20,000 feet of tinned copper wire that is soldered to the main connector ring, shown above.



This is a 20 meter directional receiving array. Tim has arrays like this for all bands, 80-10 meters. Each antenna consists of a 1/4 wave vertical, spaced 1/4 wave apart.

Let's have a look inside the shack. First, however, you should know what a multi/multi station is used for. A multi/multi station is a Multi-operator / Multi-radio contest station. In the large DX contests, these large stations are in a separate category. Four times per year, Tim invites a dozen or so of the best contest operators from around the world to join him in his shack to work the contests and have fun. The K3LR station has an impressive track record of success, having won (#1 in the USA) an impressive number of DX contests in the multi multi category, especially since 2004. Tim has hosted over 100 different contest operators during the 22 years they have competed in Multi Multi.


This is an excerpt from a chart showing just how winning K3LR has been in the ARRL SSB contest.


Tim, in the shack showing the operating positions. Each operating position works just a single band.



Tim, K3LR and Fred, AA7BQ standing before a few of K3LR's grand prize trophies.



Two of the many single band 1500 watt amplifiers that are used at K3LR using a single 8877 tube. No band switch, just pure legal power on a given band.



Another pair of amps, as well as a matrix switch used to configure the receiving antennas. Above to the right is where some of the hardline enters the shack.


A typical operating position. Note the four rotators for a stack of antennas. Every position has either an IC-7800 or an IC-7700 radio. In all, there are about 10 IC-7800's in the shack, including a hot spare. While heavily recognized by ICOM, there is no corporate sponsorship whatsoever. Tim buys nearly all of his gear used, at bargain prices.



Tim at the 20 meter position. We fired it up and were able to work a station in Sweden right away. The operator on the other end refused to believe that we were "barefoot", running 100 watts. You can't understate the power of a 24 element array!

There are also some great videos including a drone fly-over that is impressive. Check out:



K3LR Icom video
http://www.youtube.com/watch?v=wlXu7Q3h8RI
http://www.youtube.com/watch?v=jo2mCNJdvdk

K3LR Fly By videos
http://www.youtube.com/watch?v=OMzdTQzJjSc
http://www.youtube.com/watch?v=kimSQsEKqGE

K3LR QRP QSO
http://www.youtube.com/watch?v=6Tk4kz5OeIE



More photos in larger formats are available on my Google+ page here

Also, for the detailed (accurate) specs of the station and it's history, see http://www.k3lr.com

[나곡해수욕장(6K5VLI)]

It is gorgeous....!

[윤민식]

무슨일을 하는지 안테나가 하도많아 모르겠군요.