I finally decided to build the 6m ‘Flowerpot’ coaxial vertical antenna to monitor the 6m WSPR beacon as well as other 6 meter frequencies. The flower pot antenna is easy to construct with minimal parts, costs and setup. Once again there is a abundance of information on the Internet regarding this antenna. I will therefor not go into full detail on how I constructed my version of this antenna.
Here is a few links to visit if you interested in building this antenna:
1. Flower Pot Antenna Calculator
2. Half-Wave Flower Pot Antenna - VK2ZOI
3. Flowerpot Antenna for 6 meters - VKIDL
4. Video: Build an EASY 6 Meter (50 MHz) Vertical Antenna (Using just RG-58!)
5. VK4PK_My_6m_Flowerpot_Antenna-v1.0.pdf
6. VK4PK - My 6 Meter Flowerpot Antenna
The dimensions for the antenna was calculated using the free Flowerpot Antenna measurements of Hayden VK7HH available HERE. I set my frequency to 50.1 MHz. The resulting calculation is shown in the image below but differs from the measurements of VK7HH.
I used the measurements as provided by Hayden VK5HH.
With all the information now on paper, I was ready to move onto the next phase and that was to gather all the materials I was going to need.
Materials that I used:
Antenna Dimensions:
My final dimensions is listed below:
Working Frequency: 50.1 Mhz
Upper Radiator : 1376 mm
Lower Radiator: 1346 mm
Coil: 14 Turns
Building the antenna and the construction changes I made:
1. Get rid of the 25mm PVC pipe in which the antenna is housed. The PVC is flimsy and wobbly. A glass fiber rod / pole / housing will solve the issue.
2. Look at the images of how I construct my coil and how it is fitted.
3. I did not use a fishing line to secure the top radiator. (See image.)
4. To save on coax I constructed the top radiator out of 3mm insulated electrical wire. The bottom radiator and coil consist of coax cable. Length = 1385 mm I removed the insulation at both ends to tie the top ( split the strands into half en make a little loop. I then used a sucker sweat plastic stick to secure the loop to the outer PVC. See image ) and solder the bottom end to the bottom radiator element. Seal with heat shrink tubing and marine silicone and then with self amalgamating tape.
5. The 300mm x 25 mm wooden broom stick or dowel was placed inside the PVC pipe at the bottom of the antenna to provide rigidness to clamp the antenna to a mast.
6. The coil consisted of 15 turns of coax (40mm former). This must still be rectified. I used a 50mm former and therefor the coil turns should have been 14 turns. The coax feeds trough both the 50 mm coil and the 25mm PVC pipe. (See images)
7. The 25mm PVC pipe protrudes through the two 50mm end caps. I drilled a 25mm hole through each of the end caps.
8. I used 6mm and 8mm Heat Shrink Tubing after soldering the insulated 3mm copper wire to the bottom radiator and then sealed further with self amalgamating tape and silicone.
Changes that I still want to make before the antenna is installed:
1. Replace the flimsy and wobbly 25mm PVC with something more rigid.
2. Play around with the top radiator. Instead of using insulated wire rather use a stainless steel whip or an ex army clip together antenna. Another option would be to use a rugged "tape measure" tactical antenna.
3. The aim here is to build the antenna as cheap as possible Adding onE of the radiators as mentioned in 2 will increase the cost dramatically. However it is for you to decide how much you want to spend on the antenna.
