Second Tower

Son Blake helped out by digging the hole for a second tower as a Father’s Day gift.  Thank you, Blake!

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This second tower is intended to be the support for one end of a 40 meter dipole. The other end will attach to the other tower.  The towers are aligned so the dipole will aim toward Europe.  This tower might also support a 6 meter yagi some day.

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Is It Working?

Here is a PSKReporter screen snap showing the spots from other stations hearing me on the new 20 meter yagi antenna.  I’m running 10 watts on JT65.  This was taken at 7pm local time.  The beam is pointed toward Europe.   Yup, it’s working.

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Tower!

Wish I could shout it.  The tower is up!  Unbelievable thanks to KC0RF, John Neilson for his extremely hard work.  First look shows the Hygain 203BA yagi on top of the 60 ft. Universal Towers aluminum tower.  First qso was with R3OZ, European Russia with 10 watts and got a report of -11 db on JT65. That was followed up by another European Russian station calling me, R3HH. It’s working!

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The balun we chose is a current mode balun consisting of 5 turns of coax through a stack of 4 ferrite cores.  The cores are 43 mix 2.0 inches, taped together.  The coax is splayed with as much distance between turns as possible to reduce capacitance.  Refer to the ARRL Antenna Book 23rd Edition chapter on Transmission Lines, Table 20.7.  This balun will provide 5000 ohms impedance at 14 MHz on the outside of the coax shield.  It looks like this before mounting at the yagi feedpoint.

John, KC0RF, finalizing the balun.

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An advantage of this type of balun is that it can handle full legal power because only the common mode current on the outside of the coax is passing through the cores.  The main rf current is inside the coax and not passing through the cores.   It will not heat up like other types of baluns.  This balun has the approval of one of my favorite  rf experts and engineer Bill, N0CU.

What a bird sees…..

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Although the tower is supposed to be self-supporting we still attached Phillystran guy cables.  This enables sleeping better at night.

Repainting To Control Summer Heat

Temperatures of 104 degrees Fahrenheit were common inside the shed when outside temps were still only 85.  This had to be improved.  Step one was to cut two 6″ circular vents into one gable and add a solar powered fan.  No noticeable improvement.  Step two was to cut in a second vent in the opposite gable.  Same result.  Third step was to cut in a 8″ X 16″ vent midway up the north wall.  Same result.  Fourth step was to paint the shed white.  This helped.  Inside and outside temps since have been nearly the same.  The cute barn red shed is now almost ugly white.  But it’s cool inside.

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Why the concern? We were worried more about the batteries than the equipment.  The electronic equipment was still within specified operating range at 104.  Sources say batteries, on the other hand, can exhibit thermal runaway (catch fire) at 122 degrees.  Summer’s highest temperatures hadn’t even arrived yet.

Web-based Coax Switch

Another box checked on the station upgrade list.  The web-based coax switch enables selecting one of 5 antennas remotely over the Internet.  It is a Remote Rig Model 1289 Antenna Switch.

In this picture we have three antennas installed and room for two more.

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