Sunday, February 9, 2014

Another linked dipole (Heavy Duty)

Sometime ago I ordered the wrong size gold connectors from Hobby King and ended up with 4mm vice the 2mm that I wanted. I did reorder but decided to keep the 4mm connectors as I figured they may come in handy one day. Today was the day!

After using my light weight SOTA linked dipole that covers 15, 20, 30 and 40 meters, read about it here, I decided to make a heavy duty (HD) version of the same dipole. In practice I would rather use an End Fed on a summit vice a dipole however, the HD linked dipole would come in handy at a base camp and I wanted to have an antenna capable of more than a couple of watts.

I used 18 gage wire (vice 26 gage teflon coated wire), 4 mm (vice 2 mm) connectors and a BNC connector for the center. Here are the measurements I used. Your measurements/requirements will vary depending on the portion of the band you want it resonate, mine is cut for the CW QRP portion of each band.

Linked Dipole measurements
This of course is not a hard build but it can be time consuming. Eventually I got into a rhythm and everything went together without incident.

The supplies

Center connector
 I am in the habit of adding fingernail polish to the screw and nut in order to hold them together. You could use Loctite as well but mine is stashed away in a tool bag somewhere.

The ends of the 20 meter section

With the connectors

The 30 meter section with connectors

20 and 30 meter section tied together

and connected.....

Progress thus far (I keep the antenna wrapped up as I go as it is easier to work with this way)
The video below demonstrates how I wrap my antennas. I am using an end fed zepp in the video but it works well with dipoles. This way I do not need to use anything to wrap the wires with and the antenna deploys with getting tangled. It works very well.

CAUTION: It does take practice!!!!!!

I had plenty of help during this build!

SOTA kitty helps by holding one end of the 40 meter section

The 15 meter stub with loop for support rope (also the end section of the dipole)

Completed antenna
It is helpful to use a different color of wire for each section. Ideally I would rather use bright colors but I did not have any on hand. Of course you can make it using the same color wire but for ease of section/band identification it may be helpful to use bright color shrink wrap.

This antenna is not anything new but it is easy, inexpensive and fun to make. It is heavier than anything else I use but much lighter than a G5RV and easier to deploy. Moreover, no tuner is required!

Too cold today to test it (18 degrees as I write this) but I will get down to the park and give it a go next week sometime.