Our HAM Station

///////////////////////////////////////////
Summertime Station and Antenna Projects At AB1OC/AB1QB

Posted: 14 Aug 2016 07:25 PM PDT
https://stationproject.wordpress.com...at-ab1ocab1qb/


Summer is the time of year that many of us work on our antennas and improve
our stations. AnitaÂ*AB1QBÂ*and I did both of these things at our QTH this
summer.
Removing Lower SteppIR Yagi From Tower

OurÂ*SteppIR DB36 YagisÂ*were due for some maintenance so we took them off
our tower.Â*A special thanks to all the members of the Nashua Area Radio
Club who helped us remove, recondition and reinstall our antennas!Â*Matt
Strelow,Â*KC1XXÂ*ofÂ*XX TowersÂ*and Andrew Toth provided equipment and know how
to safely removeÂ*our two largeÂ*SteppIR DB36 YagisÂ*with help from the rest
of us.
Lowering Antenna With Electric Winch

TheÂ*SteppIR DB36 YagisÂ*weigh almost 200 lbs each and Matt made good use of
his electric winch to lower them.
Antenna Coming Down The Tram Line

The picture above shows the lower antenna coming off the tower. We used a
Tram Line system to lower both antennas to the ground so that we could
rebuild them.
SteppIR DB36 Antenna On The Ground

TheÂ*SteppIR DB36 YagisÂ*are quite large. They have 36 ftÂ*booms and the
driven elements are almost 50 ft from tip to tip! They completely fill up
our back yard when they are both off the tower.
Element Pole Sun Damage

The rebuild process began with a careful inspection of both antennas. They
were both in good overall condition with some sun damage to the paint on
the fiberglass element poles.
Disassembled SteppIR DB36

WeÂ*removed all the element tubes and sweeps from both antennas for
rebuilding. The picture above shows the disassembled upper antenna.
Reconditioned Stepper Motors Installed

All four Stepper motors on both antenna were replaced. These motors move
metal tapes inside hollow element tubes to adjust the length of
eachÂ*antennasÂ*4 movable elements. TheseÂ*adjustments areÂ*done automatically
by controllers in our shack which receive frequency information from the
radios which areÂ*connected to each antenna.
Reconditioned Element Sweep Poles

All of the element housing poles were cleaned, prepped and painted with a
UV resistant clear coatÂ*to protect them from further sun damage. The poles
cleaned up like new.
New Element Sweeps Ready For Installation

The assembly of all the new element sweep tubes (shown above) was done
next. Each antenna has six sweeps.
Element Pole Preparation

The end of each element pole must be prepped with a tape system which
ensures that the poles are seated properly, sealed to and firmly attached
to the sweeps. This process and the associated assembly and tightening of
the element couplers was the most time-consuming step in the rebuild
process as it had to be repeated a total of 24 times.
Rebuilt Element Assembly

Heres a picture of one of the rebuilt element tube assemblies. The ropes
support the element tubes and keep them aligned when the antenna is up in
the air. These elements are attached to the antenna motorsÂ*with couplers
and clamps.
SteppIR DB36 Yagi Rebuild Complete

The picture above shows the lower antenna with all the element tubes
reattached. There is quite a bit of additional prep work associated with
adjusting all the supports and taping all the exposed areas of the antennas
which are susceptible to sun damage. Also, all the electrical wiring on the
antenna must be checked to ensure goodÂ*electricalÂ*connections and
goodÂ*overall condition of the wiring.
Ground Test Setup

The final step in rebuilding the antennas is to test their operation on the
ground. This ground test is done to ensure that all the motors are working
correctly and that the element tapes move smoothly inside the rebuilt
element tubes.
Ground Test Results

Another important part of the antenna Ground Test is to confirm that the
antennas have a consistent resonant frequencyÂ*and SWR on all bands. The
resonant frequencies and SWR levels are far from those that would be
measured when the antennas are on the tower atÂ*operating height. The idea
here is to confirm that a resonance exists and that its frequency and SWR
readingsÂ*are repeatable as the antenna is adjusted to different bands.


With both antennas rebuilt, its was time for Matt and Andrew to return and,
with help from folks from our club, reinstall the rebuilt antennas on our
tower. The video above shows this process. It is quite something to see!
The installation took about 3 1/2 hours.
Updated SteppIR Controllers

The last step in theÂ*SteppIR DB36Â*rebuild process was to install the latest
firmware in the associatedÂ*SDA100 Antenna Controllers. There areÂ*some
integration issues between the updated SteppIR Firmware and ourÂ*microHAM
systemÂ*but we areÂ*gettingÂ*those worked out with help from the folks at both
SteppIR and microHAM.
Icom IC-7851 With Display Monitor
I recently had a major birthday milestone and Anita surprised me with a new
radio anÂ*Icom IC-7851. This radio is an upgrade/replacement for ourÂ*Icom
IC-7800. While the two radios are quite similar in their operation and
interfaces, I did not want to install the IC-7851 until the SteppIR
antennasÂ*were reinstalled and all of their upgrades were working properly
with our current radios. With the antennas done, it was the finallyÂ*time to
install the new radio!
Icom C-7851 Transceiver

TheÂ*Icom IC-7851Â*has several important performance upgrades. The most
impactful one is aÂ*new low phase noise oscillator which significantly
improves RMDR performance compared to the IC-7800. The IC-7851 is in
theÂ*top-tier of Transceivers in Sherwood Engineerings tests. The receivers
in the IC-7851 are very quiet, have excellent Dynamic Range and perform
greatÂ*in whenÂ*close-in interference is present.
Icom IC-7851 Display Monitor

TheÂ*IcomÂ*IC-7851Â*has a higher resolution and faster display. It also
supports higher resolution external monitors so we installed am
upgradedÂ*display monitor along with the newÂ*radio. The IC-7851 has aÂ*number
of new networking featuresÂ*and supports stand-alone remote operation over a
LAN and the Internet. We are planning to use these capabilities to addÂ*a
secondÂ*remote operating gateway toÂ*our station. More on this in a future
article.

The combination of the rebuilt antennas and the new IC-7851 Transceiver has
our station performing better than ever. The antennas are working as well
or better than when they were new and the IC-7851 has significantly better
receive performance compared toÂ*its predecessor and is a pleasure to use.

We will be hosting theÂ*ARRL Rookie Roundup RTTY contestÂ*for our club
members who have received their firstÂ*licenseÂ*in theÂ*last 3 years next
weekend and were going to use the new radio and rebuilt antennas for the
contest.

This project wasÂ*completed in a little over two weeks and was a lot of
work.Â*I could not have done the project without the help of the manyÂ*folks
in the Nashua Area RadioÂ*Club.Â*Again, a big Thank You to all the folks in
our club who helped me with this project! I hope that many of you will be
able to findÂ*some timeÂ*to operate from our upgraded station.

73,

Fred,Â*AB1OC
Filed under: Antennas and Feedlines, Shack Design and Construction, Tower
Construction and Maintenance Tagged: Antennas and Feedlines, Remote
Operating, Shack Design and Construction, Tower Construction and
Maintenance, Yagi