Recent content by trees

My plan is to use relatively large wire with few turns. I could use either a ferrite rod, or toroid. Polyolefin heatshrink will hold the inductor to the fiberglass. The ferrite should give me high Q. The magnetic flux is providing the inductance, yes? The inductor is simply to cancel the...

I'll also add that the toroid will be the only wound wire on the antenna. Antenna will not be helical.

Considering using wound ferrite core incorporated into fiberglass whip. If the toroid were large enough I could wrap thermaleze wire and center the toroid on the fiberglass shaft. Has anyone tried this?

I was wondering about the permeability of the plating. I acquired some plated pipe, and am considering using as is. Also thinking about stripping the plating off...but, if the rf permeates the nickel and travels on the copper underneath, then it would be a good material and removing the plating...

Nickel plated copper pipe, good, efficient conductor for making an antenna? Or, is nickel too lossy. The current will travel on the outer surface, skin effect, yes?

Installed and tuned up the antennas I altered with heavy copper stranded wire. Been using them for a few weeks now, and they perform better than any antenna I've ever used.

I have a question concerning phased verticals and feed point impedance shifting. I understand that a single vertical will/can change impedance when mutually coupled with a second independently tuned vertical when combined/phased. My question is this, can the system reactance after mutual...

Photo of the Francis base. (I think this is/was a 4.5 foot Hot Rod.

Hi. The antenna in photo 1 is a Francis antenna, but it's neither the WD, or Amazer. Those Antenna's were very long, I believe. (Just a little shorter than 1/4?) I also think that they used a form of capacitive loading, and the length, combined with capacitive loading, helped the efficiency and...

As far as Francis antennas go, they look to be pretty much the same today, as those of old. I had never broken one open to look inside... I made sure to wear eye protection and heavy gloves/clothing. Fiberglass is nasty stuff when it's splintering apart.

I'm not sure as to the actual age of the antenna, but I don't think its vintage. I think it's probably two, maybe three years old. I don't know that there's much difference between then, and now. The construction seemed solid, the inner core was well formed, and the wire turns were even and...

Inside a Francis antenna.... Interesting, I believe that's enameled wire. And, it's wound with two wires sharing a common feed point, but electrically isolated from each other. I wonder if this was the inspiration for the Van Ordt quad wrap? I know it inspired me to make my own version.

If you're going to phase the antennas you will need a phasing harness. You will need to determine your desired phase angle, and cut the coax to the correct length. (Forced current approach) Yes, coax length will matter.

If you had a small rotisserie motor, and a roller jig, you could refinish the blank with some flexcoat. The Francis antennas will give you fiberglass splinters in your hands when the original epoxy coating weathers off... Not fun.

I might be wrong, but I think the objective with helically wound wire whips is to achieve the proper inductance to cancel the capacitive reactance introduced by shortening the antenna? Additional, closely spaced wire wound inductors, electrically isolated from each other should capacitively...