All posts by Michael Struzik

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

 

 

 

Add CTCSS PL Tones to Your Old VHF Rig

Last week I gladly accepted a free Azden 2m FM transceiver model number PCS-4000 that was offered to me.  You have to love the old free stuff!  The only capability this 25W rig was missing is the ability to transmit CTCSS PL tones or sub audible tones to activate a repeater.

I found the manual and schematics online and found that this rig was built to accept a tone generator as an add-on. See below.

PL Tone Mod Circuit

Below is a photo showing the jumper locations for the tone input.  I soldered some leads with a home brew disconnect to easily remove the cover in the future.PL Tone Mods

Below is a photo showing an added 1/8″ mono jack for the input tone.

PL Tone Mods

For an input tone, I used an Android cell phone with a frequency generator App to generate the PL tone.

PL Tone Generator

I can experiment with other ways to generate the tone such as an Arduino with RC filters etc.  I can also try to insert a 700 Hz tone with my Arduino keyer for MCW.

Below is a photo of the rig set up for a local repeater.

Completed Mod to add PL Tones

So now to quote Pete Juliano “Bob’s your uncle”!!!

73,

Mike, AB1YK

My SSB BitX-40 build from VU2ESE

Below is a photo of my BitX-40 kit from Ashhar Farhan VU2ESE in India with my very own custom designed case.  The kits are available from http://www.hfsigs.com/

The top cover shown is powder coated steel mesh.

BitX-40 Enclosure

The sheet metal housing was designed in a solid modeling software package called Onshape. This web based software is free to use if your designs are to be available to anyone who signs into an account.  This design is “in the cloud” and considered “open hardware”, available to anyone who would like to use it.  Below is a screen capture of my Linux desktop running Onshape within a web browser.

BitX-40 Enclosure CAD Design

With access to a CNC punch press and a 90-ton brake press, a coworker of mine helped out with a bit of “government work”!

I left out some of the detail in the housing to let others enjoy the use of a drill and allow for some creativity with a customized placement of components.

BitX-40 Enclosure with Board

Some of the wires are not needed but may be useful in future “hacks”. The image below shows some of the wires removed from the “Molex” connector.  A small sharp object can be used to push in on the barb to remove the contact for a future project.

BitX-40 Cables and Connectors

See http://bitxhacks.blogspot.com/

I used my sketch to drive the LCD screen and the SI5351 chip using the Adafruit library.  The checkered block moves left and right between the arrows to indicate when I am at or near the end of travel with the tuning potentiometer.

BitX-40 Frequency Stationary
Stationary

When I move the block all the way to the right with the potentiometer it turns into an arrow and automatically increases the frequency. To make it stop just turn the potentiometer to the left.

BitX-40 Frequency rising
Frequency rising

I like the ability to scan the band without having to turn a knob!

Below is an image showing 12v and 24v voltage regulators and electrical tape on the housing tabs.  12v is for the majority of the wiring and I used 24v for the IRF510 PA.  The black tape looks nice behind the black mesh cover.  while testing I measured about 4W RF output with 12v feeding the PA and 16W RF at 24v.

BitX-40 Enclosure

The bottom has extruded “feet” along with stick on feet to keep the rig from sliding.

BitX-40 Enclosure

I used an SO-239 connector for the antenna.  I saved the BNC connector from the kit for test gear.  The red terminal post is connected to 32v from a repurposed HP printer power supply.  The barrel jack is connected to 16v from the same supply.

For more information on the case, you may contact me through my QRZ page.

73,

Mike (AB1YK)

Home Brew Your Own Arduino UNO

The first question you may ask is, Why would I want to build my own Arduino UNO?  Economically speaking it does not add up in your favor after you acquire the parts and consider the time it takes to put it all together.  This is especially true when you consider that a Nano “clone” could be purchased for around $3!  You might have a permanent use application that makes building one your best option?  Maybe you just like to learn and do stuff just because you can!

The unit below is built on a prototype shield that has become the main board.  For my keyer application, I have no need of USB communications and I can keep the wiring down to only what is needed.  The 5v regulator will soon have a small heatsink as it gets warmer than I would like.

Homebrew Arduino UNO

Below is the other side of this board.  I used #4-40 screws as “legs”.

Homebrew Arduino UNO

Instructions for building one yourself on a solderless breadboard can be found at https://www.arduino.cc/en/Main/Standalone

Instructions on burning the bootloader with another Arduino can be found at

https://www.arduino.cc/en/Tutorial/ArduinoToBreadboard

and

https://www.arduino.cc/en/Tutorial/ArduinoISP

If you run into trouble like I did by getting the “wrong” ATmega328 micro controller you can get work around instructions at http://www.crash-bang.com/resource/bootload-atmega328/

73,

Mike AB1YK