A while back I posted a photo diary of the 40/80 meter coil loaded dipole that I built. It's actually fed with 450 ohm ladder line, so I guess it's technically a "doublet". The original thread of the build is here: http://www.worldwidedx.com/amateur-radio-antennas/30736-coil-loaded-dipole-build-photo-diary.html. Since the original build, I went back and replaced the main 40 meter wire segment with some lighter weight and more flexible wire to make the portable installation easier. I also cleaned up the wire connections by putting on terminal lugs.
I needed a way to get the doublet up in the air without having to rely on trees, which aren't very easy to find in the desert and some RV campgrounds. Looking around the garage, I found a fruit picker that I no longer have a use for that has a sturdy telescoping 12' fiberglass mast that I decided to repurpose.
The fruit basket was just held on by a hose clamp, so that came right off.
Next, I purchased a item that is made locally in Southern California called the Flagpole Buddy. This is a simple in concept but smartly designed attachment made to install on an RV ladder. It's intended to be used to support tall telescoping flagpoles and it comes in 1.5 inch and 2" diameter sizes.
I purchased the 2" diameter size because I intend to purchase a longer telescoping mast at some point.
Here is a picture of the flagpole buddy installed with the 12' mast installed.
I wanted more height, so I found an old fiberglass Hawaiian Sling fishing spear that I wasn't using any longer. It's about 4' long and unscrews in half for storage. The tip is detachable and there was already a hole drilled in one end for the rope. A couple of U bolts made a quick attachment to the fiberglass mast.
We took the RV out to visit my sister's family for Thanksgiving so up went the antenna. Here's a couple of shots of the doublet attached to the mast, about 22 feet in the air:
Remember, the main wires are cut for 40 meters, with loading coils and a tag end for 80 meters. The end was just tied off to a nearby fence with the ends about 6 feet off the ground.
The ladder line just loops down the side of the RV, attached to a small 1:1 current balun and then to a short length of coax to get the feedline inside attached to the LDG AT897 tuner that is mounted on the Yaesu FT-897D. I originally had the balun attached directly to the back of the tuner with the 450 ohm ladder line run directly inside, but I didn't like the way the balun was stressing the SO-239 an the back of the tuner so I attached the coax.
With this setup I'm able to easily tune up 40 & 80 meters (of course), as well as all of the higher HF bands. I was able to check into the Southern California Navy MARS net from Arizona on 75 meters with no problems. In fact, conditions were very favorable, so I was checked in as Loud, Clear. With just 100 watts I was able to chat far into the night on 3.840 with all of the other stations that were present from NV, AZ, CA, and UT
Simple, effective, cheap, and fun
I needed a way to get the doublet up in the air without having to rely on trees, which aren't very easy to find in the desert and some RV campgrounds. Looking around the garage, I found a fruit picker that I no longer have a use for that has a sturdy telescoping 12' fiberglass mast that I decided to repurpose.
The fruit basket was just held on by a hose clamp, so that came right off.
Next, I purchased a item that is made locally in Southern California called the Flagpole Buddy. This is a simple in concept but smartly designed attachment made to install on an RV ladder. It's intended to be used to support tall telescoping flagpoles and it comes in 1.5 inch and 2" diameter sizes.
I purchased the 2" diameter size because I intend to purchase a longer telescoping mast at some point.
Here is a picture of the flagpole buddy installed with the 12' mast installed.
I wanted more height, so I found an old fiberglass Hawaiian Sling fishing spear that I wasn't using any longer. It's about 4' long and unscrews in half for storage. The tip is detachable and there was already a hole drilled in one end for the rope. A couple of U bolts made a quick attachment to the fiberglass mast.
We took the RV out to visit my sister's family for Thanksgiving so up went the antenna. Here's a couple of shots of the doublet attached to the mast, about 22 feet in the air:
Remember, the main wires are cut for 40 meters, with loading coils and a tag end for 80 meters. The end was just tied off to a nearby fence with the ends about 6 feet off the ground.
The ladder line just loops down the side of the RV, attached to a small 1:1 current balun and then to a short length of coax to get the feedline inside attached to the LDG AT897 tuner that is mounted on the Yaesu FT-897D. I originally had the balun attached directly to the back of the tuner with the 450 ohm ladder line run directly inside, but I didn't like the way the balun was stressing the SO-239 an the back of the tuner so I attached the coax.
With this setup I'm able to easily tune up 40 & 80 meters (of course), as well as all of the higher HF bands. I was able to check into the Southern California Navy MARS net from Arizona on 75 meters with no problems. In fact, conditions were very favorable, so I was checked in as Loud, Clear. With just 100 watts I was able to chat far into the night on 3.840 with all of the other stations that were present from NV, AZ, CA, and UT
Simple, effective, cheap, and fun
