For a few years our group was lucky to have a ham friend that was chief engineer of an AM station that only transmitted during the daytime and then would switch to a different site (many miles away) at night....so, our 160 contest group would operate using his 48' tower as a 160 vertical at night then disconnect well before the AM station would come bk on the air...we had a very potent signal back then...73/K6SDW

Also appreciated the explanation of the ARRL publication library.

Amazing info about antennas, I didn't knew that the top part will behave as a capacitor, thank you!

Very clear explanation of an important antenna principle. Thanks Dave.

Thanks, Dave. 73

This is pretty much what we used to use on 160m. G5RV with the open wire shorted and fed against earth through a tuner. The inductor was in the tuner. G5RV is 102 feet top.

Hey Dave, I’m new to radio and really enjoy all the content you put out. If you ever wanna come to alaska and be an Elmer for a few days, you’d be welcome.

@David Casler Please correct me if I am wrong. An antenna loading employs inductance to lower antenna resonance (by lengthening the electrical length) at the cost of reduced bandwidth. However, when using a capacitance hat and a loading coil, these components may counterbalance the bandwidth changes while establishing the antenna's resonance within the 160m band. In contrast, a capacitance hat raises resonance (by shortening the electrical length, necessitating more wire) and widens the bandwidth. Additionally, incorporating extra radiating elements (like doubling wire with a ladder line and multiple capacitance elements at the top) can decrease the antenna's resistance, thus improving its efficiency.

@traveller-nl

Жыл бұрын

Correct about the coil at the base. It “lengthens” the antenna. So does top loading with a capacity hat. Both work in the same direction. A small improvement would be a coil in the center, but one would need more inductance than when base loading. So, the wire resistance and wire capacitance would diminish the benefits. But it would still be an improvement on antenna efficiency. Talking about efficiency… with some rough calculations, one can expect this quite compromised antenna to have an efficiency just about 10% on good ground. Hence the title, 160m or bust. Due to the too short physical length the radiation angles will be high in the far field plot. That pretty much cancels the benefits of a vertical while even a compromised horizontal (with loading coils) would be more efficient with a likewise radiation pattern. A full wave loop around the house at fence hight might be interesting too with about the same efficiency and pattern, but way less complex than coils, capacity hat and awkwardly long ground radials.

I knew W1 that ran a 3 tower array on 160 to work across the pond. A more practical antenna for a backyard is a square/loop 65 feet per side, yes high angle but efficient, makes up for for the angle.

Your cheated when you searched QST by using his call sign. The ARRL still has not provided a way to do compound searches of QST, other than the old pdf system. Why the League continues to have such poor web technology I don’t understand, or for that matter continue to use a non U.S. based company to host the QST platform. 13:28

This is a stupid antenna. Use the top 100+ feet horizontal wire with big, and I mean big, loading coils with low loss R, you will have a better antenna that might work well. All these dumb magic weirdo antennas don't work well but hams seem to like them anyway.

@ChartreuseKitsune

Жыл бұрын

It's not some new novel gimmick antenna or something like that. It's a rather well proven vintage antenna called a T antenna. They are/were very common on bands lower than 2 MHz where the height of a true vertical becomes extremely impractical. For stations on say the 630 and 2200m bands they're even more common.

@traveller-nl

Жыл бұрын

I wouldn’t call it stupid. Sometimes you gotta make it work with what you got (material/real estate). But I can see what you’re trying to say. A small improvement would be a coil in the center, but one would need more inductance than when base loading. So, the wire resistance and wire capacitance would diminish the benefits. But it would still be an improvement on antenna efficiency. Talking about efficiency… with some rough calculations, one can expect this quite compromised antenna to have an efficiency just about 10% on good ground. Hence the title, 160m or bust. Due to the too short physical length the radiation angles will be high in the far field plot. That pretty much cancels the benefits of a vertical while even a compromised horizontal (with loading coils) would be more efficient with a likewise NVIS radiation pattern at less than a 1/2 wave above ground. A full wave loop around the house at fence hight might be interesting to consider instead with about the same 10% efficiency and pattern, but way less complex than coils, capacity hat and very long ground radials in weird shapes within the property but folding around the house.

Thanks. N0QFT