Thanks DB ...no arguments here...I want to make sure what antenna I want to use before I throw it up...what are some ways to controll mode currents? Grounding? Rolling up coax? ChokeSome people say one is and others say the other is. There have been some heated "discussions" on this board in the past on this topic, with people calling each other idiots simply because they disagreed with the other person over this topic.
IF you control for the common mode currents that the Imax does not, in and of itself, limit and control, then in most cases it will outperform the Maco at the same mounting height. This is only because the Imax is slightly longer, and thus the maximum radiation point on the antenna is slightly higher, and with antennas, height is might.
That being said, IF you don't control for said currents, then the Maco may well outperform the Imax. It depends on any number of factors including mast length and coax length, some lengths of these components simply attract common mode currents while others naturally resist said currents.
IF you mount both antennas at the same tip height and you notice a difference, then you have a problem with one of the antennas, plane and simple
In many if not most cases, when switching from one of these antennas to the other (or really whenever installing a new base antenna), on old piece of coax, which may or may not have some form of damage, is generally also replaced, if not upgraded completely. This can, in and of itself, skew the results towards whichever antenna is newer, but it is often not factored in if even mentioned with said claims...
The DB
The main thing on fiberglass antennas is the noise...if they didn't have so much hash they probably would be a bit betterrf choke or line isolator, google ugly balun or RF choke should find many sites and instructions how to build the RF choke
The main thing on fiberglass antennas is the noise...if they didn't have so much hash they probably would be a bit better
5 turns on a 100mm former works.
Have a look at this youtube Vid on why fit a balun or choke to eliminate cmc .
It's a very good practical demonstration.
The main thing on fiberglass antennas is the noise...if they didn't have so much hash they probably would be a bit better
Even with the added ground plane kit I don't see how the imax can be as effective on one band as the maco. For a person wanting to work 10,11 and 12 meters it really shines. I've even heard of people using them on 15 and 17.
We know it's very wide banded compared to the maco. Doesn't that mean lower q and less efficiency? Can you really have your cake and eat it too? Look at the coil of wire and caps used for matching in the imax and then compare it to the maco. It seems to me the imax just has a lossy matching network.
I haven't done any antenna modeling or anything scientific but people that have switched from an imax to a maco or something similar seem to have better TX and RX. A couple of cases were with the same coax and same height. When I replaced my imax with a maco I raised the antenna also so the results were skewed.