I believe that this is also called a tunnel effect, the radio waves are tunneling through a duct formed by temporary ionized layers. Something similar can occur with whales who seem to be able to communicate over distances of thousands of miles also by some sort of an acoustic tunneling effect of so…

People may be somewhat less familiar with radio wave skip or skywaves in this age of FM and cable TV but many people still have experienced it at some time. As far as ducting getting VHF signal at longer then usual ranges might be a bit of a surprise. But it’s not the wtf moment that happens wit…

steamer, tengineer, yaught sailor & more all get the point. Maybe by and by we’ll exchange our call signs (those that have them). today the dark path, following the terminator is a common vhf (and other) pathway for DX. Skip refers to acually utilizing a skip off the ground and again off the tro…

HIHI … trick question. [image] jimrr: reading "through the back side of the loop? With the old loop antenna, heading toward the signal source will give a course indicator deflection toward the source, if the antenna is rotated to the backside the deflection will read away from the source and…

[IMG_5405] By adding the circular sense antenna signal to that of the polar diagram the true direction can be easily found. The resulting diagram is also called the heart shaped diagram.

[image] Dutchie: By adding the circular sense antenna signal to that of the polar diagram the true direction can be easily found. The ARN-7 ADF used on the B-24 incorporated a sense antenna … the Lady Be Good reported that the ADF was not working properly and they requested a DF steer from a …

[image] jimrr: dark path, following the terminator is a common vhf (and other) pathway for DX. Was hoping someone would mention that. As a side note – On a whim I tested for an amateur license a year or two ago. Looking at some sample tests had shown me I should be able to comfortably pass …

[image] jimrr: Nothing unusual Ducting in general is not unusual, occurs about 25% of the time off California and about 50% of the time in Gulf of Oman. But how often does land hundreds of miles away display on the radar on the 24 mile range? I’ve seen it twice in my career. [image] jimr…

There are two possible explanations for this phenomenon. Anomalous propagation Anomalous propagation is an atmospheric condition that bends RADAR beams. This causes objects that would not normally appear on RADAR to show up on the screen. It can occur that the RADAR beam bends downward, striking o…

It’s both I assume. But what are the chances that the phenomena will be understood by the mate on watch the first time it’s seen? Why couldn’t you explain it to the Dutch Weather Bureau? Here’s how it goes: The ship is hundreds of miles from land. It a beautiful clear sunny day. Nothing in sight. …

[image] Kennebec_Captain: Why couldn’t you explain it to the Dutch Weather Bureau? We were on not a very good footing with the Weather Bureau because each mate on a selected ship was rated for the quality of his weather reports. They seemed to know our weather situation better then we did. I…

Atmospheric Ducting

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Atmospheric Ducting

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