I believe the lower section is shorter to take into account the velocity factor of the radiowave in the coax. 9 turns in the resonant choke is chosen for a frequency of about 135Mhz - just below the band of use (it is an inductor).
It turns out a vertical dipole for 144 MHz and a dipole for 433 MHz. However, there are doubts that the aluminum foil should be closed around the circumference?! If it is not closed, then it will not have a shielding property.
This was the easiest to follow instruction video I have found for this antenna yet. Was able to build it with extra stuff laying around on a lazy Sunday. Lost nothing, gained a well working antenna and some knowledge. Thank you sir
I made one of these a few years ago It tunes well and works well mounted above the roof line on my house. The only downside is that the pipe wall is thin and it does flex in the wind. This causes the SWR to move during operation.
Maybe it would be an idea to put a cane or dowel rod in the centre to give the pipe a bit more rigidity? I don't think it would alter the operation of the antenna.
Why wouldn't you just use the center conductor of the RG58 antenna cable measured out o the proper length instead of soldering a piece of 14 ga wire in? it would seem to me one less joint to possibly fail. Just curious.
There is no way that it 1" pipe. It looks like 2". The paper you got the plans from says 1" (25mm) but 1" is about the length of the end of your pointer finger and that pipe looks to be double that. I really hope you did use 2" and got those results because I just happen to have a 4' long 2" pvc pipe I want to use to make this since I just got an old Kenwood TR-7800 in mint condition I want to use it on. Plus I could use it on my dual band HT as well.
Thank you for making this video, Mike. I saw your comment on an Easy German video about being an officer and now wanting to learn German. I am also learning German, but not purely out of interest. You see, I am in high school in India and want to go to Germany. I don't know why I'm writing this here, but anyway, good luck (Viel Glück)!
great idea Mike, i live in compromised location with no outdoor antennas permitted and i was thinking of making 450 ladder line slim jims, but this look like a good idea also for me situation. 73s
I thought I was the only one to ever find that type of spray nozzle. The other three I have are the regular twist kind. Cool, and nice video. GL & HH & have fun
