Wednesday, December 30, 2020

Sycamore Tree Removal

Damaged DE
I have a "forest" of trees directly East of my EME antennas.  In the winter when the leaves and sap are gone, it seems not to be a huge problem to my moonbounce operations, but in the spring and summer it provides a "brick wall" that keeps me from hearing all but the very strongest EME signals.   Two of these trees (directly behind the house) are Sycamores.  It turns out that Evelyn is severely affected by the dust these trees develop under their leaves in the summer.  If she steps out on the back porch, she will start exhibiting an allergic reaction in less than a minute!  Thus, these trees HAVE TO GO!

Once we decided to have these two Sycamores removed, we chose RealTree Tree Services (a local tree service) and they were able to schedule the removal for today.  I told them we just wanted to "drop" the trees over the lip of the hill where they sat.  Therefore they did not need to be cut up nor did we need the stumps ground down.  This kept the costs down.

These two trees were directly East of my EME array and provided significant blockage from 70° to 110° in Azimuth. This was the direction of my MoonRise and that's where I need to see the moon to be able to work stations in Europe. In the photo on the Top-Left you can see how close my antennas are to these trees even when the antennas are turned broadside to the trees.  And you get a bit of an ideal of how tall the trees are.  The tree cutters estimated the largest one was 65-feet tall.  The image on the Center-Right shows a better view to indicate the height of the trees.

Over the last 3 years I have been on EME, these trees have grown to the point where they prevent my antennas from pointing in their direction.  I first noticed this early in February of 2020 when my SWR suddenly shot up.  I tracked that problem down to the fact that the trees had reached out and GRABBED the driven element of one antenna and actually pulled it apart.  (See the image on the Top-Right of this Post.)  Click on any image to see it larger.

For multiple reasons I asked my Grandsons (Owen and Grant) to come down today to help out.  I knew they could clean the debris from the yard and could cut any of the trees that fell across the "trail" we used to access the HF tower.  They showed up about 8:15 a.m. and brought their friend, Logan, as well.  Evelyn had made a BIG breakfast for them with ham, eggs, biscuits, fried apples, hash browns, and hot chocolate.  After they ate (and the tree service had not arrived) I had them do a small amount of tree trimming at the mailbox.  Later I had them check our whole house generator and replace the battery in it.

When the tree service arrived, they saw that we had three strong men available so they cancelled their own ground crew.  The one guy that did all the major work then paid my "ground crew" $100 of what he had planned to charge me.  You can see on the Bottom-Left photo my Ground Crew cutting up the large tree.  It fell across the "trail" so they got to work with their chainsaws and cleared the way. Logan is on the left gathering up one of the ropes for the tree service guy.

Click HERE for a 30-second video of the trees coming down.  I was a little slow in starting the video for the large tree falling so it is not included.  That large tree definitely shook the ground when it hit.

There are still a LOT of trees to my East but I'm hoping that by removing these two large trees (which were so close to the antennas that the branches were touching the antenna elements) that my signals toward MoonRise will improve. Maybe it is wishful thinking but I feel like I can see more "sky" than I could before removing these two Sycamores. Time will tell. However, on Thursday morning I can tell there is a great deal more light coming into my bathroom. Those trees were definitely blocking a bunch of sky.

Monday, December 28, 2020

Weatherproof Cable Entry Port

Roxtec EzEntry™ 10/10
When I built my current EME antenna system 3 years ago, I used a PVC box to hold the T/R relay and the LNA close to the antennas (see photo at left.)  Since I was using cables which already had the terminations installed and I did not want to remove those connectors, my only option was to drill a hole large enough for the connector to pass through the wall of the box.  Those holes are marked by Purple arrows in the image.

As I began construction of my new XPOL array, I needed to purchase a new and much larger plastic box to hold the multiple relays (5 this time) and the two new LNA's.  Because I have purchased a pair of matched 1/4 λ cavity LNA's for this system, I need a MUCH bigger box than before.  These LNA's (click HERE to see them) are 17-inches long.

This new system will require FIVE large coaxes plus multiple control wires to enter the box.  In the old system I had THREE large coaxes and needed to drill holes in the box large enough to pass the connectors on the ends of the cables.  I was never able to manage to waterproof those large entry holes well enough to keep water out of the box.  As we all know, water is the enemy of electronic equipment.

Looking for a more elegant solution, I came across the Roxtec EzEntry system.  This solution provides a cable entry seal that can be used to weatherproof pre-terminated cables without the need for removing the terminations.  That is AWESOME! You can use any cables with connectors already installed and be assured the Cable Entry Port is weatherproof and insect-proof.  It is also a system that can be modified to add or remove cables with ease.

Different size cables are easily installed.  To adapt the sealing modules to different cable sizes, simply peel off layers from each half of the blue modules until it fits the cable.  It is important that you leave a  0.1 to 1 mm gap between the halves of the blue module when placed around the cable.  Unused blue modules can stay in the frame for use as "spares" in the future.  During installation all parts are lubricated with the supplied lubricant.  Click HERE for a 5-minute video of the installation process.

Module Installation
Once all the modules and cables have been installed, an integrated compression unit is tightened with a Hex key.  This compresses the modules for sealing, squeezes out the excess lubricant, and the installation is complete.

I was really excited to learn about this product which I believe will greatly improve my ability to keep water away from the relays and LNA's for my new array.  This system is available in many sizes but I decided to go with the Roxtec EzEntry™ 10/10 model.  It allows for up to 10 cables each ranging in size from 0.138-0.650 in (3.5-16.5 mm).  This is more than large enough to accomodate 1/2-inch Heliax which has a diameter of 0.51 inches (12.95 mm.) Overall size of the unit is 2.76 x 6.61 in (70x168 mm) which will easily fit my new box.

I also think it is important to note that you can install the Roxtec EzEntry frame in the box without the blue modules and run the various cable into the box through the frame.  Once everything is connected and positioned, THEN you can install the blue modules to seal the cables.  This makes the process very convenient.

I have found several suppliers of these products online.  The model I have decided to use (Roxtec EzEntry™ 10/10) is available for about $85 including shipping.  I feel that is a super low price to pay in order to weatherproof cables entering my Relay/LNA box.