Troposcatter

[towerdog]

Troposcatter inside and out:

This article says it all and gives explanation to how I was able to talk well beyond the horizon on sideband under power (although some of it might been ducting).

Tropospheric forward scatter, thats how they reliably talk on 10, 11, 2 and .7 meter sideband over hundreds of miles with no skips in coverage.

And I thought tropo was just for the military or an obsolete alternative to microwave links. The article says that may be the reason why so little of this form of propagation is known, because it was classified.

 

[Captain Kilowatt]

Classified?? I wonder when that was written. Hams have known about and used tropospheric scattering and tropospheric ducting both for decades and decades.

 

[davegrantsr]

Troposcatter inside and out:

This article says it all and gives explanation to how I was able to talk well beyond the horizon on sideband under power (although some of it might been ducting).

didn't i say that on your earlier thread?

 

[towerdog]

yes, you suggested tropospheric scattering, but you did not write me a book on the subject.

I am still not convinced its all tropo on upper HF that extends com a moderate range over the horizon, although I am sure it does often play some role.
I think it might actually be more ionoscatter below 50mhz, according to Hansen which I will maybe read up on tomorrow night.

 

[Captain Kilowatt]

This reminds me of something. Way back about 100 years ago I used to talk quite often in the mornings around 7:30 or 8:00 with a lady about 35 miles SSE from me. She used to talk to her husband on his way to work and I would join in after he arrived. We would be using AM and signals would start off at about S-5 and gradually increase to S-8 or better. Not bad for a 35 mile hop on AM with legal power both ways. We did both have dual polarity beams however. After a while as the sun rose higher the signals would start to drop and waver somewhat. Sometimes we would have better signals V-V others it would be better H-H and the really odd times it was better when one of us was V and the other H. After the signals started to waver it was only about another 15 minutes or so when they would drop right out to S2 or less eventually becoming non-existant altogether.

 

[towerdog]

near a body of water, ducting perhaps? i have seen such on the coastal waters of NC, Cubans, lots of'em. As you get near the bridge the radio goes nuts, then you reach the other side and it goes dead.

 

[Captain Kilowatt]

LOL I am in Nova Scotia. I am never very far from water. Actually she was on the coast but it was an all land path between us. Iam on the other side of the province somewhat near the Minas Basin but not right on it. Ducting is far more prevalent on tbe VHF and UHF bands than on the upper edge of HF.