Category Archives: Homebrewing

Articles and other information related to Homebrewing, station building, kit building, and other custom Ham Radio projects.

How did I hang my dipole 50+ feet high in the trees?

Dipole Antenna Tree

I wanted to make an article that would explain to anyone who visits my home or QTH that would answer the question on “How did you get that rope so high in the trees and how did you get that rope over the perfect branch?

I started out with a fishing pole and a 4-inch long stick from the woods.  After a few attempts of getting the stick up and over the tree with the fishing line it finally made it over the tree and back to the ground.  I then reeled in all the fishing line while pulling a string over the tree.  After the string, I used it to pull over 3/8” poly rope.

I came up with the following idea to get a rope over the perfect branch.

Dipole Antenna Tree

The 3/8″ line holds an old branch from the woods in the center. The yellow rope to the left is the “control line” and the right side has a half rotten log as a weight secured with a slip knot as shown below.

Dipole Antenna Tree

In the diagram below the light blue line represents the yellow control line from the photo.  As you lift the whole unit you should consider that the weight of the control line may offset your balance as you go higher.    The magenta line shows the string with a slip knot.  When the half rotten log made it over the desired perfect branch by combinations of pulling the 3/8″ rope at either end (shown black) and/or the control line (shown light blue) I pulled out the slip knot and the half rotten log fell over the perfect branch along with the string (shown magenta).

Dipole Antenna Tree

I replaced the string with rope and then a wire rope loop (shown red). The wire rope will not fade and fall apart from the sun’s UV rays. The yellow circle represents a pulley for the poly rope that holds up the dipole. When the poly rope breaks down from UV, wear and tear it can easily be replaced by lowering the pulley.  I added weight to maintain proper tension on the dipole antenna as shown below.

Dipole Antenna Tree

In theory, the tension will remain the same even in wind storms when the trees swing back and forth. It turns out that an old cast iron rotor from my Toyota was the perfect weight for the application!

73,

Mike AB1YK

 

 

 

Go Kit for Field Day and EMCOM

We’ve been thinking about building a portable Go Kit for VHF/UHF Emergency Communications (EMCOM) and Field Day Applications for a while now. The following is a list of our requirements for a Go Kit –

  • 2m and 70cm operation with FM simplex and repeaters
  • APRS capability and tactical display for portable coordination
  • Digital messaging capability
  • Weather band monitoring capability
  • AC Power with flexible battery backup options

A plan to build our Go Kit came together during our trip to the Dayton Hamvention this year.

EMCOM Go Kit - Kenwood TM-D710GA At Dayton
Kenwood TM-D710GA At Dayton

The heart of any Go Kit is the Transceiver. We’ve been using Kenwood equipment for our APRS iGate for some time now and we have had good results with it. Kenwood’s latest 50W transceiver with APRS is the TM-D710GA. This unit provides full support for APRS tactical applications and now includes a built-in GPS receiver making it ideal for our Go Kit application.

EMCOM Go Kit - AvMap GeoSat 6 APRS Tactical Display
AvMap GeoSat 6 APRS Tactical Display

We have been using the Kenwood TM-D710 along with an AvMap GeoSat APRS display in our APRS iGate setup and the combination works very well. The AvMap display lets one see the location of portable and mobile APRS stations on a map display. This arrangement is perfect for coordinating activities in an EMCOM situation. The AvMap GeoSat 6 APRS display is no longer in production but I was able to locate a nearly new unit on eBay.

EMCOM Go Kit Packaging

 

EMCOM Go Kit - iPortable Enclosure
iPortable Enclosure

We had a chance to look at the iPortable enclosure at Dayton and decided that their Pro 2 4U deep unit would be a good choice for our Go Kit application. The iPortable enclosures are based on a portable rack mount case and include a DC power system, speaker and headphone hookups, a light, and provisions for a cooling fan.

EMCOM Go Kit Construction

 

EMCOM Go Kit - Radio Shelf
Radio Shelf

With all the components in hand, we began the construction of our Go Kit. Reliability is important in any portable system like this so we put some time into securely mounting all of the equipment and neatly arranging the cabling. First came the shelf which holds the Kenwood transceiver and a SignaLink USB sound card. A combination of drilling the shelf to secure gear with large cable ties and #8 stainless hardware was used here.

EMCOM Go Kit - Coax Connector Cables
Coax Connector Cables

Our iPortable case was equipped with both SO-239 and N-connectors on the front panel to allow for antennas and feed lines equipped for either connector type. To make the change over between the connector types easy, we installed separate PL-259 jumper cables for each connector. One simply connects the appropriate jumper to the radio.

EMCOM Go Kit - Display and Power Shelf
Display and Power Shelf

The power and AvMap display shelf were next. The AvMap display mount was dissembled and modified to accept a custom mounting bracket.

EMCOM Go Kit - PWRgate Battery Interface and Charger
PWRgate Battery Interface and Charger

The iPortable enclosure was drilled to mount a West Mountain Radio PWRgate to handle backup battery charging and management. The PWRgate supports instantaneous switching between an AC power supply and a backup battery and can accommodate a wide range of battery types and sizes.

EMCOM Go Kit Backup Battery
Backup Battery

The PWRgate was configured to properly charge our 18AH AGM backup battery. Note the use of a fuse in series with the battery for safety reasons. We used a Powerwerx SPS-30DM adjustable power supply set to 14.5Vdc to operate our Go Kit and to provide the proper charging voltage for our AGM battery.

EMCOM Go Kit Operation

 

EMCOM Go Kt - Diamond X-30 Antenna and Mast
Diamond X-30 Antenna and Mast

The last piece of the setup was the antenna. We wanted something that was portable, easy to set up and would provide good performance. We choose a Diamond X-30A 2m/70cm ground plane antenna and mounted it on a 12′ fiberglass push up mast. The feed line is made from 25′ of LMR-400UF coax. Several bungee cords are used to attach the mast to a fence post or other vertical structure.

EMCOM - Finished Go Kit In Use
Finished Go Kit In Use

The picture above shows the completed Go Kit in operation. We typically set one side of the Kenwood TM-D710GA to operate as an APRS transceiver and Digipeater and the other side to operate on a local repeater or simplex FM. The SignaLink sound card is used with a laptop computer running Fldigi and NBEMS for messaging applications. The iPortable case has a 13.8V lighter socket which connects to a power brick to power our laptop PC.

EMCOM Go Kit Packaged for Transport
Go Kit Packaged for Transport

The Go Kit is quite portable when closed. All of the equipment and cable connections are enclosed and protected by the case’s removable end caps. We’ve tested our Go Kit during our club’s weekly repeater net and it worked great. The first real use of our new Go Kit will be at Field Day this year. It will be located in our public information tent and will be used as a “talk-in” system.

Fred, AB1OC

2017 Field Day Prep – New Tower Test

We decided to put up a third tower as part of our 2017 Field Day operation. The new tower will support a tri-band yagi and wire antenna for use by our Digital and GOTA stations this year. Our Field Day plans call for this tower to be located on the middle-level soccer field at the Hollis-Brookline High School. To overcome terrain limitations, we decided that our new tower should be a 60 ft setup.

The project began with some mechanical design and planning for a new, heavy-duty Falling Derrick System. Mike K1WVO, Dave N1RF and I secured the necessary materials and hardware to make the new Falling Derrick System.

Tower Test - Equipment And Tools On Site
Equipment And Tools On Site

The team in the two pictures above met at our QTH this past weekend to transport all of the equipment for the new tower to the high school for a test setup.

Tower Test - Setting Up The Tilt Base
Setting Up The Tilt Base

The first step in the test was to locate the tower base in the center of our test area and ensure that it was level. Steel stakes were driven and retainers added to secure the base to the ground.

Tower Test - Building The Derrick
Building The Derrick

Next, we assembled the falling derrick and the first section of the tower to the base.

Tower Test - Assembling The Tower
Assembling The Tower

With the Derrick in place, we assembled the remaining sections of our 60 ft tower on the ground.

Tower Test - Driving Guy Anchors
Driving Guy Anchors

WIth the tower, Derrick and base together; we carefully located and drove the steel stakes for guying the tower, the derrick and for anchoring the pulleys associated with the falling derrick system. With this done, we made up and attached two levels of guys between the tower and the anchor stakes.

Tower Test - Completed Heavy Duty Derrick System Ready To Lift
Completed Heavy Duty Derrick System Ready To Lift

The tower is lifted by two wire cables which run between the derrick and the tower. We made these cables up to length during our test session. Multiple cables are used to ensure that the tower is fully supported during the lift.

Tower Test - Completed Derrick System - A View of the Tower
Completed Derrick System – A View of the Tower

Here’s another view of the tower and Derrick prior to the lift. We supported the tower on a ladder to make the initial lifting easier. The ladder will also be needed on Field Day to allow our tri-band yagi to be installed on the tower prior to standing it up.

Tower Test - Capstan Winch Used To Lift Tower
Capstan Winch Used To Lift Tower

There is a considerable amount of rope that needs to be pulled through several pulleys to lift the Tower/Derrick system. The pulleys provide mechanical advantage and slow the lift rate to a safe level. We used a heavy-duty gasoline powered capstan winch to pull the considerable length of rope required to lift our tower into the full upright position

Tower Test - Lifting The Tower
Lifting The Tower

With our crew fully briefed on the process and safety procedures, it was time to lift our tower. The picture above shows the lift in progress. Our setup ensures that no one needs to be in the tower’s fall zone during the lift.

Tower Test - The Tower Is Up!
The Tower Is Up!

Here’s a picture of the tower after it was up and fully guyed. Our new heavy-duty Derrick system worked very well and lifting the tower was completed smoothly and safely with very modest effort.

The Nashua Area Radio Club Tower Test Team
The Nashua Area Radio Club Tower Test Team

After a few pictures, we took the tower down and disassembled it. We had quite a few members turn out to help us with our new tower test. Thank you to everyone who pitched in to make our third tower project a success! We are looking forward to using it during Field Day 2017!

Notice: falling derrick tower systems can be dangerous if they are not engineered, built and used properly by a well-trained team. The tower system described here is unique and is not a standard falling derrick system. Significant steps and material choices were taken to ensure the safe use of the system described here to put up our tower Time was spent to train the team who used the Derrick system to use it correctly and safely. We do not recommend the system here to others as the engineering, materials, and training required for its safe construction and use may not be readily available.

Fred, AB1OC

Hashtags: #ARRLFD

QRPGuys Iambic Paddle Build

I’ve been practicing a lot of CW lately and had ordered a QRP guys iambic paddle from their website qrpguys.com awhile back. I went to the CW class on Saturday morning, which got me in the CW mood. After knocking some items off the honey-do list I was getting a little bored on Saturday night so I headed down to the shack and dug out the iambic key kit I had ordered.

I’ve never done any kit building or anything slightly engineer-y until joining the club. I don’t always understand why things work and building kits (even simple ones help me along). This kit didn’t look too hard, although it has a 4 out of 5-star difficulty rating on their website, so I jumped right in!

I made sure I started by sorting out all the parts in an orderly fashion.Iambic Paddle Build  I learned this much from working countless hours after Christmas and birthdays on Star Wars lego kits that are made for children, but built by adults after the kids get frustrated 15 minutes after starting!

I then got to the fun part of soldering. This was different than what I’ve done in the past as I started with soldering all the mechanical parts together by applying a small amount of solder and then checking to make sure everything lined up before putting a lot of solder on. Iambic Paddle BuildI enjoyed this as it was a large area to solder and it didn’t matter so much if my soldering skills aren’t very good! There were only a few electrical components to solder and that part was rather easy, even for my limited skills!

The toughest part of the whole build was assembling the paddles. You can see from the picture there are four nuts (and lock washers) that are to be assembled on the inside of the paddles with very limited space. TIambic Paddle Buildweezers were an absolute necessity – and earplugs for any youth that may be hanging around. After many – and I do mean many – attempts of dropping and picking up nuts and washers I finally got the washers and nuts in place and fastened.

Iambic Paddle Build

I was thrilled to have succeeded and ran out to the car, where my radio is hooked up at the moment and gave it a quick test run. Below is my not-so-professional video which shows my not-so-professional CW skills.

The paddles work well. The black pads do stick together a little when you push on both paddles at the same time, but I am very happy with my tiny QRP paddles! I am thinking of cutting slots in the sides and attaching a velcro band to attach to my leg to keep the paddle in place in the hopes that I could operate it with one hand. Let me know what you think or if you’ve built this kit before.

73,

Jamey (KC1ENX)