Warmer weather carrying Cape signals further

[raccoonradio]

There's a name for it but I forget what it is, but as we get warmer weather, signals from the Cape
are traveling up to the North Shore, more so than before at least. Scanning the dial here in Beverly
I found I was getting WXTK 95.1, WCOD 106.1 and yes even WKPE 103.9 and WOCN 104.7 (the latter
two despite being so close to WBCN and WBOQ respectively). The 105.1 from Prov. (WWLI?) was also
coming in (WBOQ's stick is in Gloucester, I think, maybe 10 miles from me--I was over near
the Montserrat train station, etc.)
But yes despite being not all that far away, 103.9 and 104.7 were coming in fairly well... the warmer
weather can float up signals from the Cape, R.I., and even Conn. (I have picked up WTIC-FM from
Hartford or "KC 101" from New Haven on occasion)

 

[DanStrassberg]

There's a name for it but I forget what it is,

IIRC, the phenomenon is called tropospheric ducting.

 

[argytunes]

That's a great idea for a radio contest or promotion:

During the next month...submit the call letters of the radio station that'll benefit the most from tropospheric ducting?

The winner receives an all-expense paid vacation to Mattapan and back!! ;D

argytunes

 

[raccoonradio]

I was almost gonna say the word "ducting"...yes that is definitely the term now that I remember it. thanks!

 

[webcastboy]

I've noticed that with the warmer weather, suddenly WBRS and WICN come in a lot better at my place in Brighton.

There's a site with daily forecasts for the likelihood of tropospheric ducting carrying signals. These maps are not terribly good at predicting the actual ducting of signals (which can travel for 100's, even 1000's of miles) since it's such an unpredictable phenomena. But I check the maps daily and see if I'm in a hot zone that day. If so, I'll periodically scan the dial and see if I catch a distant station.

http://www.dxinfocentre.com/tropo.html

Once, a couple of summers ago, I had a 90.3 from Wisconsin completely override WZBC even though I was only 15 miles from WZBC and had a hi-gain antenna aimed at Chestnut Hill. Got to listen to the farm report for about an hour, then over a mere 30 second span it just faded out and WZBC faded back in. Nifty effect.

 

[raccoonradio]

Years ago a friend of mine picked up what was then WBCS 96.9 while in Wisconsin; "Wisconsin's Best
Country Station", you might say

During warm weather:

--picked up FM talk station from Philly (WWDB 96.5) while in Lynn
--when WMWM used to sign on at noon (I was doing a show; this was before we had a comp. to keep
us on air), I remember pulling into the SSC parking lot just before noon and finding a signal on 91.7...from Florida.
WPCC 91.7, Pensacola Christian College
--while in Western MA, an NPR station from N.C. was coming in.
And in Beverly I picked up an NPR station from Carbondale, IL.

 

[BostonRandy]

When I did afternoons at WCIB (101.9/Cool 102) - Falmouth/Hyannis, it was not uncommon to get calls from listeners as far south as Virginia Beach during a good wave of tropospheric ducting.

By the way, the Cape is a great spot for tropo & e-skip from April through October. One incredible e-skip on a Saturday in July 2003 obliterated Boston, Providence & Hartford signals to the Cape as I logged more than 170 stations from 20 states and Canadian provinces.

 

[Eli Polonsky]

I've noticed that with the warmer weather, suddenly WBRS and WICN come in a lot better at my place in Brighton.

Can an only 25 watt (ERP) signal such as WBRS be strong enough to be caught and amplified by "ducting", and could the results of a "ducting" effect be heard in such a short a distance as from Waltham to Brighton, which are less than ten miles apart?

I'd think it's possible for WICN, but I recall that, some years ago, WBRS used to be plagued by some sort of problem with their antenna or transmission line, perhaps leaky co-ax or connectors, that allowed moisture, condensation and ice to enter during damp and cold weather causing a spike in their reflected power and decrease in their forward power until a consistent spell of warm, dry weather dried their antenna system out. If this problem has recurred, (or was never repaired properly), that may be the effect you're hearing increasing their signal during warm, dry weather.

Also some years ago, I recall that WMFO at Tufts U. had the opposite problem with their antenna. Whenver there was a heavy rainstorm, big snowstorm, or a lot of icing, their output power would drastically increase rather than decrease, and they could be heard all over the west suburbs which are normally in the null of their directional pattern! I can't guess what could've been going on with their antenna to have caused that, but they have recently replaced their antenna and that's no longer happening, and it's somewhat of an improvement overall. I've heard that it's actually putting out their authorized 125 watts ERP in their prime easterly direction (in all weather conditions) for the first time in years.

 

[jlehmann]

I've noticed that with the warmer weather, suddenly WBRS and WICN come in a lot better at my place in Brighton.

There's a site with daily forecasts for the likelihood of tropospheric ducting carrying signals. These maps are not terribly good at predicting the actual ducting of signals (which can travel for 100's, even 1000's of miles) since it's such an unpredictable phenomena. But I check the maps daily and see if I'm in a hot zone that day. If so, I'll periodically scan the dial and see if I catch a distant station.

http://www.dxinfocentre.com/tropo.html

Once, a couple of summers ago, I had a 90.3 from Wisconsin completely override WZBC even though I was only 15 miles from WZBC and had a hi-gain antenna aimed at Chestnut Hill. Got to listen to the farm report for about an hour, then over a mere 30 second span it just faded out and WZBC faded back in. Nifty effect.

It's actually E Skip that would've brought in a station from Wisconsin. ES is usually when stations over 500 miles come in, and it usually won't last longer than a couple of hours. ES will also start in the bottem part of the band and work it's way up as it gets stronger. Sometimes it will just stay in the non-comms during a weak opening. Tropo is usually less than 500 miles, and will be strongest from afternoon overnight into the morning. It usually doesn't creep up out of nowhere like E Skip does.

This map here is a great indicator of when tropo is going on, because it uses the ham radio APRS system, which puts coordinates out over 144.39 MHz along with other information.

http://www.mountainlake.k12.mn.us/ham/aprs/path.cgi?map=na

You can find out more info about all of this on the WTFDA (Worldwide TV/FM DX Association) website: http://www.wtfda.org/