Do more radials on a 160m vertical bring more improvements than shown by simulation? Most simulations show that going above 32 radials on 160m brings minimal improvement, say 1 db to 2 max. Even for
Ignacy, There's a lot of published information that addresses your question. Some material is rooted in commercial applications and even more in the amateur literature where modeling is compared with
I think Paul wants to know the "real" situation, not theory. He want to know if the theory is 100% in accordance with real big stations with many radials on the antennas 73, Jorge CX6VM/CW5W -- 73, J
Jorge, N6LF's material is based largely on measured results in support of theory. Paul, W9AC --Original Message-- From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Jorge Diez - CX6VM Se
What is the simulated radiation resistance with only 32 radials? Resistance above 37 ohms reduce the efficiency. I needed >90 radials on my 160m and 80m verticals to bring it below 40 ohms. 73 Peter,
OK thanks Paul how can you measure that a radial system is still good over the years? Maybe the cable is degraded, or is cutted in some points if animals are around. Is any easy way to determine that
"On the other hand, some really loud stations n 160m, say 5-10 db above the crowd, use a massive amount of radials. This is for inland stations, far away from salt water." Curious minds would like to
I think you would have to look at the details re the really loud stations. They probably do have good radial systems and also have particularly good ground/water/soil for fairly long distances around
Do like the (LF/MF) broadcasters (or at least what they used to do) ... measure field strength at several few points when the antenna/radial system is new, then measure at the same points every year
The Potomac Instruments FIM-41 is capable of directly-read field strength measurements and has a spec'd measurement range up to 5 MHz. Would like to have one myself. Measured field strength graphs t
You could measure the current in each radial with a clamp on RF ammeter. Especially useful if the original currents were measured. This might separate damaged from ok radials although for my 8 radial
Author: Mpridesti via TowerTalk <towertalk@contesting.com>
Date: Fri, 2 Dec 2022 12:47:11 -0500
In addition to what Ed, N1UR suggests, I also measure the resistance between the center conductor and the shield of the coax in the high meg ohm scale of the meter. Of course you want an open circuit
Over the years, I've learned that those who think there's a difference between "real" and theory don't know enough about one or the other. The contribution of adding more radials is most important if
A good ham friend of mine in Southern California has been a broadcast engineer for most of his life. He has worked at several stations over the years, and by the FCC, he has to measure the field stre
YES! The earth is a big resistor. Soil quality affects transmitter field strength two ways. First, loss in the soil very close to the antenna make the antenna less efficient. Radials reduce this comp
Author: Kelly Taylor via TowerTalk <towertalk@contesting.com>
Date: Fri, 2 Dec 2022 12:29:15 -0600
I suspect the main reason some folks disparage theory is the failure to take into account differences between the theoretical installation and their own. Maybe Sevick put his short vertical in an ope
At Dayton/Xenia antenna forum this year 2022, N9NB had a pretty interesting talk on low band verticals. The key take-away from that was that you could reasonably determine your actual ground loss ba
how can you measure that a radial system is still good over the years? Maybe the cable is degraded, or is cutted in some points if animals are around. Is any easy way to determine that the radial sys
On the other hand, some really loud stations n 160m, say 5-10 db above the crowd, use a massive amount of radials. This is for inland stations, far away from salt water. I think this describes my sta
On the other hand, some really loud stations n 160m, say 5-10 db above the crowd, use a massive amount of radials. This is for inland stations, far away from salt water. I think this describes my sta