2 Meter DX'ing

[kg4uuj]

Hi everyone,

I got my 1st 2 meter DX QSO on a 4 watt HT last night during a thunderstorm. I was in Paducah, Kentucky and made a contact with a man in Battle Creek, Michigan. This is about 500 miles away from where I was. I was using a Baofeng UV-5R with the stock antenna.

I was calling on 146.52 when the man called back to me. He asked for my location and I told him 4th and Broadway. He then asked "in what city?". I assumed he was close by, so I told him that I was in Paducah, Kentucky. With laughter he replied that he was in his home in Battle Creek, Michigan. We chatted for 2-3 minutes before his signal began to fade.

A couple minutes later I heard another operator calling out, so I answered and he was just a couple miles away from me. I don't know what enabled me to make the long distance contact, but apparently it ended just as quick as it had started.

Just had to share....

73's

Mike, KG4UUJ

[ZL1DAS]

Hi, what time of the day was it? The propagation mode was most likely tropospheric ducting. 73. Bernard

[kg4uuj]

It was around 7pm on Saturday, 7/7/12. What is the process that you mentioned?

Mike, KG4UUJ

[ZL1DAS]

Hi Mike... This was TROPOSPHERIC DUCTING: something you have to be there at the right place at the right time. Compare it to winning a lotto ticket....It happens only when inversion layers which are laminar flow patterns: meaning the same laminar pressure and flow are meeting a second set of the same and are piggy-backing  but at dissimilar parameters [I am simplifying] and then are forming a so-called duct in between these layers [imagine the comparison: as a fibre-optic cable does the same at a miniature scale]. The most DX by this mode has been done between EA8 and DL with a QRB of 2900km and they were using low level rigs. If you have a thunderstorm regionally you must have had layers of different air flow parameters meeting these criteria. Final assessment: TROPO DUCTING...   That should get one hooked on 2m DX..  Check out MS and EME if you are interested in more of this stuff...

[ZL1DAS]

There is a good article on Wikipedia: http://en.wikipedia.org/wiki/Tropospheric_ducting  It sheds more light on this. To fully explain it you have to delve into physics and specifically optics, there is a lot of mathematical gobblegedook involved.....

[NG9R]

As Bernard said, it was most likely tropospheric ducting, which usually is a product of weather, usually a temperature inversion, most common in eh summer and fall moths  but can happen year round. There are several methods of long distance VHF propagation and I find them very interesting. This past weekend we had Aurora where the Aurora curtain was strong enough and far enough to the south we could actually reflect VHF signals of of it and work stations well beyond normal range. On 6 meters it can be on SSB and CW on 2 meters it is usually CW only as the distortion caused by the aurora makes it very hard to understand voice signals. Sporadic E, common on 10 meters and 6 meters, can occur even at 2 meters and higher, although ti is pretty rare and usually short lived, at least above 6 meters. There are other modes, many that require special operating techniques, such as meteor scatter and bouncing signals of off large objects high in the air like airplanes and even off of the moon. Mostly used at microwave frequencies, rain scatter is another method of working station well beyond line of site.

[N4RDU]

Mike, another phenomenon that affects 2 meter propagation is Sporadic E Skip. This occurs when the E layer of the ionosphere is refracting radio waves back to earth just as with HF frequencies. This can support 2 Meter DX, but what you encountered was more than likely Tropo Ducting. Just another thing to think about when you turn your 2 meter rig on.