Comparing the LOG to the small-vertical-loop, aka a Wellbrook, LVP, MFJ broadband preamplified antenna:
Just some quick comparisons that might help on "visualize" what is going on: If one is familiar with the patterns of a small vertical loop already, the log will be nearly the same, even though the wires are flat on the ground.
Both have a similar directional pattern. That is, when seen from above, at skywave angles, it is mostly omni, but in reality is an oval shape. So there is some skywave directionality, but it is not huge. Down low, there are nulls that can aid in reducing noise.
The small vertical loop can easily be rotated to finely tune out a low-angle point noise source. With the log, your only option is to move the feedpoint around, so finely tuning a null is kinda' hard - so you do the best you can.
If one wants, you can envision both the log and the small vertical loop as verticals with no overhead null, and slightly oval patterns rather than a pure circle. Close, but not quite - a little squished.
Both the log and the small vertical loop have size limitations in regards to the classic pattern. Exceed these dimensions, and the classic patterns will distort into something you may not want.
That means the LOG should not exceed a full wavelength in circumference. For the small vertical loop that means not exceeding 1/10th of a wavelength. The example here is that if you go beyond a 15-foot sided square for the log, then frequencies higher than about 14 mhz will start to go squirrely. If you try to use the typical 3-foot diameter small vertical loop as a scanner antenna (disregarding any preamp limitations), then that pattern too will distort.
A log can be easily matched to the lossy ground resistance using a transformer, typically 9:1. Other ratios can still work depending on your needs. The small vertical loop needs a bit of help with a preamp typically. The log doesn't absolutely need a preamp, but depending on your gear, size and frequency of your listening needs, one may be helpful here too.
In the end, if you have a LOG in your backyard, you might close your eyes and envision a stationary small vertical loop just above the ground.
So choose what works for you. Each has their pros and cons, but they are in the same family even though they surely don't look like they are.
Just some quick comparisons that might help on "visualize" what is going on: If one is familiar with the patterns of a small vertical loop already, the log will be nearly the same, even though the wires are flat on the ground.
Both have a similar directional pattern. That is, when seen from above, at skywave angles, it is mostly omni, but in reality is an oval shape. So there is some skywave directionality, but it is not huge. Down low, there are nulls that can aid in reducing noise.
The small vertical loop can easily be rotated to finely tune out a low-angle point noise source. With the log, your only option is to move the feedpoint around, so finely tuning a null is kinda' hard - so you do the best you can.
If one wants, you can envision both the log and the small vertical loop as verticals with no overhead null, and slightly oval patterns rather than a pure circle. Close, but not quite - a little squished.
Both the log and the small vertical loop have size limitations in regards to the classic pattern. Exceed these dimensions, and the classic patterns will distort into something you may not want.
That means the LOG should not exceed a full wavelength in circumference. For the small vertical loop that means not exceeding 1/10th of a wavelength. The example here is that if you go beyond a 15-foot sided square for the log, then frequencies higher than about 14 mhz will start to go squirrely. If you try to use the typical 3-foot diameter small vertical loop as a scanner antenna (disregarding any preamp limitations), then that pattern too will distort.
A log can be easily matched to the lossy ground resistance using a transformer, typically 9:1. Other ratios can still work depending on your needs. The small vertical loop needs a bit of help with a preamp typically. The log doesn't absolutely need a preamp, but depending on your gear, size and frequency of your listening needs, one may be helpful here too.
In the end, if you have a LOG in your backyard, you might close your eyes and envision a stationary small vertical loop just above the ground.
So choose what works for you. Each has their pros and cons, but they are in the same family even though they surely don't look like they are.