Contest Station W8JI

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W8JI Station

Transmitting Antennas

Also see:

Rohn 65G

new 45G tower page

Rotating Tower page

Lightning

Station Grounds and grounding

Contesting and Boatanchor Room

Antenna System and my house station

Typical 160M setup

A ground will NOT.....

• A ground normally will not help reception. The exception is an antenna system design problem or installation problem causing the antenna system to be sensitive to common mode feedline currents
• A ground will not reduce the chances of lightning strikes

Cable Entrance and routing

There are a few islands like this where cables and conduits arriving from different directions collect.

The 4-inch diameter pipes provide easy access when new cables are installed. The pipes have drain holes at low spots, and have gravel under the pipe at those spots for drainage.

I try to segregate receiving and control cables in one pipe, and transmitting cables in the other pipe. All transmitting cables are 50 ohm, all receiving cables 75 ohm. All of the large hardline cables are 50 ohm in this picture.

Notice some cables go under the pipes and are directly buried.

The red/green taped cable with the yellow stripe is a flooded aluminum jacket "50-ohm power cable". The flooding between the jacket and the shield is a very thick sticky coating. It seals the cable in case of damage. It has a very large solid copper center, and is .625 inches OD on the shield. It is suitable for direct burial.

Other cables, like the red/white and red/yellow marked cables, are traditional heliax. Solid copper jacket heliax can be directly buried. I use the color codes to keep track of cables.

The silver cables are control cables. There are 44 shielded conductors in each control cable.

The smallest cables are receiving antenna cables.

The two black cables entering the hose clamped PVC are telephone cables.

All of my fittings are either large DIN plugs, or UHF type fittings. I only have N connectors on UHF cables. This is because a standard UHF male or female (PL-259 or SO-239) has a much higher current and voltage breakdown than a type-N connector. As a consequence of that, they are much more reliable and more immune to damage.

The two large white pipes at the bottom run under the driveway to another collection point in a recessed hole.

Click here to see a cable and wiring map at the bottom of this page.

Manhole

Across the driveway, the white pipes dump into a manhole. Rock in the bottom promotes drainage. This view is actually after more than 1 inch of rain from a severe thunderstorm!

Note the large corrugated pipe. This pipe runs to a 318-foot tall tower 350 feet away, and to the house.

There are Heliax and other cables under the pipes, although they are barely visible in the picture.

The house serves as a collection point for receiving antennas and cables from my 220 foot tower.

When covered the manhole looks like this:

Cover in place hides wiring and keeps out water. There are other cables arriving at the new building.

This feed goes to the north end of the property. The heliax and several direct burial telephone, control, and 75-ohm cables are buried outside and below the conduit. The conduit allows for easy future expansions and protects the directly buried cables. There is a vertical access point every 100 feet. The little vertical PVC pipe marks an F-11 receiving cable that goes 3000 feet to an antenna system that allows receiving while transmitters are running.

We have upgraded some towers. First step is removing the insulated base 200-foot tall 160 meter Rohn 25G vertical and replacing it with a bigger Rohn 45G  tower.

This is in preparation for mounting fixed Yagi's on Europe and Africa. These Yagi's will have a clear shot away from all other antennas towards Europe and Africa.

This is the first 150 feet of the new tower.

The old 25G is shown still standing. The horizontal line passing across the tower is a rope from an 80 meter dipole. The dipole is about 160 feet above ground. The grey cabinet at the tower base hold matching and phasing components for my 8-direction four square for 160 meters. This entire field is a mat of copper wire, having 100 two hundred foot long radials from the tower and 50 or 60 1/4 wave radials from each four square element.

For more installation pictures, see "lifting Rohn 25G and 45G towers".

This is phase I.

Phase II is installing a second 318-foot tower in the background behind the trees.

Tower Layout at W8JI

Typical 160 Meter Multi-op Contest Setup

On Top

From left to right:

Transmit antenna switches for assist or partner

Monitor for assist or partner

Monitor for run

Run transmit antenna selection

Rotating tower control

Power meter

On main desk level

Left radio FT1000MKV. This radio can transmit, but is interlocked with main radio. We normally do not use it to transmit.

Assist radio receiving antenna and audio selector

Receiving antenna direction control

K3 sub-receiver antenna selector

Elecraft K3

K3 main receiver antenna and audio selector

The receiving antenna boxes can pick up to six different receiving antenna groups or systems. Most groups or systems can pick eight directions. It also has a stereo headphone jack, and any receiver's audio can be placed on either ear. We do NOT use the headphone jacks on radios. The radio speaker lines all feed a transformer-isolated audio buss. This way any headset can listen to any receiver in any ear.

The multiplier station is interlocked. It cannot transmit while the run station is on. It can either use its own transmitting antennas, or it can share the transmitting antennas of the run station.

It has an identical receive antenna box. Six antenna groups or systems are available. As with the run station, the mult operator can hear the audio of any receiver in the room in either ear.

The radio here is a modified FT1000MP MKV.

The multiplier station has control of the receive directions for his receiving antennas.

The floor vents blow cool filtered air up behind and below the desks. This helps keep operators and equipment cool.

These are the ops in the CQWW 160 CW contest. From left to right:

Hershey, he cleans any spilled snacks up.

John K4BAI

Dan K1TO

Jim VE7ZO

Our station was the first USA to ever score over a million points in 160 contests, and consistently places first or second place USA positions. We have set several all time record scores, including 40-meter single band records. This is despite our inland Georgia location and ~1,000 mile longer path to Europe than the NE USA stations. We do remarkably well with red clay instead of salt water, although I'd rather live by the ocean.

2007 CQWW 160 METER SINGLE OP

Callsign Used: W4AN

Operator: N5OT

Those of us who knew Bill Fisher knew he was an honest competitor, he never used packet and followed the rules and spirit of every contest. When Bill won, you knew he won by pushing hard and playing fair.  

Bill Fisher W4AN set the old CQWW 160 single-op record at W8JI in 2004. His score was 753,867 points with 1495 QSO's in 56 US/Canada sections and 67 countries. That record was lost by a slim margin in 2006 when N8T achieved 776,424 points from 1464 contacts in 60 US/Canada sections with 72 counties.

In memory of Bill, we decided to bring the single op CQ160 record back to Georgia and W4AN.

The ARRL 160 was selected as a learning session to prepare for the CQWW160. Unfortunately a heavy work load and construction delays prevented the new contest station from being ready on schedule for the ARRL 160 contest. Bad weather prevented N5OT from operating the ARRL 160 at the old W8JI station, so Mark missed the warm-up contest.

The result was I (W8JI) pecked away at the keyboard, mostly with a paddle. Lacking a proficient contest op, I still pushed W4AN to 444,528 points with 1544 QSO's and 126 multipliers. This was the highest score in the 2006 ARRL 160 CW contest. The well-deserved 508,804 point all time record of K9DX with 1742 QSO's and 131 multipliers still stands and remains a goal for others. My own personal feeling is the K9DX record is outstanding, and I hope John holds that record for many more years. No one deserves a record more than K9DX.  

We were still moving equipment into the new room and wiring at the start of the 2007 CQ WW160 contest on Friday. N5OT had no amplifier during much of the opening time and experienced several malfunctions as the new station was debugged. The best receivers, a pair of stereo diversity phase locked R4C's with double balanced diode solid state mixers, were not available until the second night. One of the worse failures occurred when a loose clamp on the 200-foot omni vertical transmitting antenna caused a catastrophic and non-repairable failure in the 18-year old RCS-8V feeding all 160 meter antennas. This knocked W4AN off the air at a critical hour. When the antennas were restored, another failure forced barefoot operation through Sunday morning peak hours. 

Despite the unusual and severe hardships, Mark's skillful operating saved the day. Mark piloted the W4AN callsign to 840,486 points with 1706 QSO's in 58 sections and 69 countries. This was enough to put the record back where it belongs...under W4AN's call.

CQWW 160 CW 2007 Station

Building entrance and ground. There are many more cables there now!

Cable entrance. Every wire and cable enters via a common connection point.

Small cables are F-6 CommScope 75-ohm receiving antenna cables.

Large cable is the only transmitting feedline connected at this time.

The  row of vertically oriented white terminal blocks are control lines.

 +

Entrance panel is bonded to the electrical entrance. Early picture above. Later picture below has antenna switches.

The switches above can be quickly patched in for special radio setups in the room. Three transmitting antenna cables come down from the room above. Sixteen trunk cables exit to various towers or antenna locations.

Transmitting Antenna Matrix

The transmitting antenna system is being revised to the following system:

W8JI Antenna Matrix 9/12/09

Receiving Antenna Switching Matrix

The entire receiving antenna switching matrix was assembled just hours before the first 160 meter contest from the new barn. This switching matrix allows any of four receivers (outputs on top) to connect to any of six antenna groups in any combination. Most antenna groups can select multiple directions at the same time.

 That still wasn't enough. We added a seventh antenna feed for a dipole located about 3000 feet away! This was the primary duplex receive antenna. It was positioned broadside to the transmitting array.

One 75-ohm  coaxial cable plus a CAT-5 and four CAT-3 cables go to each receiver position.

FT-1000MP MK-V (2) W8JI mods        R4C (2) W8JI mods stereo diversity        MFJ-DSP 784B stereo connected (2)

Homebrew antenna switches at right (3)        Homebrew antenna selectors at each rig (4)

Bird (1)

The SO2R setup included the DX Doubler, allowing two radios to be used. Mark could receive while transmitting thanks to over 1/2 mile of transmitting to receiving antenna separation.

Mark had the choice of almost 40 different receiving antennas. The three switch boxes switched a 350 foot diameter eight-circle array of verticals. The middle switch selected one of eight directions consisting of two phased Beverages with 350-foot broadside separation (three broadside on Europe) in each direction (17 Beverages in the array), and 14 Beverages (most in broadside pairs) in the front array. In addition Mark had four verticals spaced 85 foot end-fire and 350-feet broadside on Europe.      

The operator can put any antenna on any radio in any direction, and select the audio feed from any receiver or multiple receivers in stereo, including full stereo from diversity reception R4C's.

N5OT Mark B. operating

Mark had sporadic faults causing the amplifier to drop off. He operated the first few hours barefoot, then had periodic failures through the contest until a catastrophic Sunday morning caused him to operate barefoot with a patched antenna. It turns out a loose tower leg clamp was behind the failures. It eventually failed totally early Sunday morning causing this failure at the 160 meter vertical antenna feed.:

When the omni-directional tower feed system clamp failed, the antenna port went open. The high open-circuit voltages caused the antenna relay to carbon track and burn, as well as lesser damage to three other ports. No more of this stuff. I'm going to change to the larger DX Engineering relay box using very large wide contact spacing  extreme duty relays.  

N5OT not operating.

W8XR    Mark A.

We had Mark A and Mark B, what could be better? Mark A drove down from Toledo, Ohio to show us his Flex Radio SDR-1000. Mark was a tremendous asset. Mark A helped with wiring and other technical issues during off-the-air periods. Mark A is nothing short of a genius!

We hoped the SDR-1000 band display would, as another operator claimed, give Mark B the advantage of "seeing pileups" when new stations or multipliers arrived on the band. Unfortunately we learned it could not do that, the wide-spaced dynamic range not able to handle the transmitter's signal despite being connected to a low dipole thousands of feet away.

since 1/30/2007