FM Reception depending on which way the wind blows?

[MarcB]

Just curious if wind has any affect on which radio station comes in on a particular frequency. Last week on a particularly windy day I was parked in the Forestville Commons Shopping Center in Forestville, CT (part of Bristol) and I had on 107.5 FM. It kept switching back and and forth between 107.5 WFCC (which is a Classical station on Cape Cod) and FRANK-FM, (which is a Classic Hits station up in Maine).

And yesterday I was parked in the parking lot on the side of the TJ MAXX/Vacant Store in the Bristol Plaza. It was a little bit breezey out and I was listening to La Fiesta 98.5 out of Long Island. All of a sudden for 2 minutes it switched to SportsRadio 98.5 The Hub out of Boston. Then it switched back to La Fiesta.

Classical 99.5 WCRB Lowell-Boston was also listenable yesterday.

 

[BRNout]

I'd say it has far more to do with humidity levels in the mid-troposphere than with wind. However, some of the same conditions (moisture, clouds) that cause tropospheric enhancement of reception can also cause wind. And, a northeast or southeast wind in that region often means storminess out to sea which will lead to reception of coastal FM signals. But there is really no direct correlation between wind and reception. You can have a windy, dry day in the wintertime (for example) and there will be no enhancement of over-the-horizon FM signals. On the other hand, a nice foggy and humid (yet windless) day over southern New England will often bring Providence and Cape Cod signals pounding in to central and western CT, western MA and southern NH.

Getting Cape Cod and Boston signals (98.5 is the best for this) in Bristol is a sign of good tropo; however, pulling in Frank from Maine is excellent dx from there!

 

[MarcB]

I guess it's that time of year. There's a mention on the Philly board that 97.5 WPEN-FM was weaker in parts of Philly than it normally is and WALK was walking over WPEN-FM in parts of New Jersey that should be receiving WPEN-FM.

WPEN-FM is licensed to Burlington, New Jersey.

 

[rbrucecarter5]

Just curious if wind has any affect on which radio station comes in on a particular frequency. Last week on a particularly windy day I was parked in the Forestville Commons Shopping Center in Forestville, CT (part of Bristol) and I had on 107.5 FM. It kept switching back and and forth between 107.5 WFCC (which is a Classical station on Cape Cod) and FRANK-FM, (which is a Classic Hits station up in Maine).

I have two ideas what might be going on.

Idea 1 - which seems more plausible given the circumstances you describe: FM patterns in the fringes for multi-bay antennas resemble moire patterns due to micro interactions between the bays, hence the flumph flumph of signal strength when driving in the country at a considerable distance. I contrast that to the only single bay station I ever heard - a diabetic mood swing had a crusty old station owner order a 6 kW transmitter on the air through a single bay to make an ERP of 2.2 kW. While in that configuration - there was no flumph flumph in the fringes. It was like falling off a cliff, the station was there, then gone with little transistion.

Now- applying that to your situation. Two stations, both fringe, both probably with multiple bays, and both generating really complex overlapping Moire patterns of coverage. The wind blows your car antenna, enough to get one station a little better than the other, and the capture ratio takes hold and you switch. I've seen coverage change in inches with a portable, especially when I switch from horizontal to vertical on the whip antenna. But never quite as dramatic as you have described.

Idea 2 - weather front linkage to the wind. I've documented on this board the dry line effect, which bring So Cal stations into West Texas regularly for those under the dry line. Any frontal system will generate wind shift, and also have a reflective characteristic to distant FM. So - you may be hearing the effect of the front, and seeing the wind at the same time.

 

[BRNout]

Just curious if wind has any affect on which radio station comes in on a particular frequency. Last week on a particularly windy day I was parked in the Forestville Commons Shopping Center in Forestville, CT (part of Bristol) and I had on 107.5 FM. It kept switching back and and forth between 107.5 WFCC (which is a Classical station on Cape Cod) and FRANK-FM, (which is a Classic Hits station up in Maine).

I have two ideas what might be going on.

Idea 1 - which seems more plausible given the circumstances you describe: FM patterns in the fringes for multi-bay antennas resemble moire patterns due to micro interactions between the bays, hence the flumph flumph of signal strength when driving in the country at a considerable distance. I contrast that to the only single bay station I ever heard - a diabetic mood swing had a crusty old station owner order a 6 kW transmitter on the air through a single bay to make an ERP of 2.2 kW. While in that configuration - there was no flumph flumph in the fringes. It was like falling off a cliff, the station was there, then gone with little transistion.

Now- applying that to your situation. Two stations, both fringe, both probably with multiple bays, and both generating really complex overlapping Moire patterns of coverage. The wind blows your car antenna, enough to get one station a little better than the other, and the capture ratio takes hold and you switch. I've seen coverage change in inches with a portable, especially when I switch from horizontal to vertical on the whip antenna. But never quite as dramatic as you have described.

Idea 2 - weather front linkage to the wind. I've documented on this board the dry line effect, which bring So Cal stations into West Texas regularly for those under the dry line. Any frontal system will generate wind shift, and also have a reflective characteristic to distant FM. So - you may be hearing the effect of the front, and seeing the wind at the same time.

Bruce, the thing is that I know the area where Marc was (quite well) and most of the stations he describes aren't really fringe. They only come in when there's some tropospheric enhancement. The exception being 98.5 from Long Island (is it still WBON?), which is usually dominant on that frequency. On a cold winter day (for example), you're not going to pick up Cape Cod, Boston or Portland, ME from that location. Even on hilltops that are several hundred feet higher than Forestville, the Boston stations are very weak - and that's if you're in an ideal location with a northeasterly view. I know because I once lived in such a place at an altitude of 900' MSL that faced northeast. Boston signals on open channels were usually available there but at a normal signal strength of 1 or 2 of 10. The signals from Cape Cod and Portland are too distant for normal reception.

Forestville is at a much lower altitude and is subject to a lot of RF from transmitters in nearby Farmington, Avon and Meriden. Line of sight to the east is blocked somewhat by Rattlesnake Mountain in Farmington and to the south and west by higher terrain in Bristol, Southington and Wolcott. So, he was enjoying the benefits of tropo.

Given the climate characteristics of that region, some light tropo is pretty common there and I recall some summers in that area where Providence stations were coming in almost every morning before 10 and evening after 4 or so.

 

[MarcB]

The exception being 98.5 from Long Island (is it still WBON?

Yes. Despite them not being 98.5 The Bone for several years, they are still WBON. They were 98.5 The Bone WBON. Then Business Talk WBZB. Then back to 98.5 The Bone WBON for a few weeks. Then went Spanish La Fiesta. Still WBON. They've been La Fiesta since 06 or 07. I forget.