Can you hear "farther" in the winter?

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kc8qln

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I live in a older larger subdivision with HUGE trees much taller than my house & antenna.

Generally speaking, when all the leaves fall, do you hear father?

In even more general terms, does foliage reduce the ability to receive signals?

Thanks
 

n4voxgill

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[Generally speaking, when all the leaves fall, do you hear father?
It depends on how close he is to you.

In even more general terms, does foliage reduce the ability to receive signals?

Yes they can
 

loumaag

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kc8qln said:
In even more general terms, does foliage reduce the ability to receive signals?
Yes, in general. More specifically some things are more affected than others and it depends on where you are. UHF is not so popular with the PS folks in the area north of Lake Pontchartrain in SE Louisiana. There are lots (I mean lots) of Southern Pine up there, ever notice how long those pine needles are? :lol:
 

kb2vxa

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Hi QLN and all,

The simple answer is "yes", seasonal changes are well documented by hams who operate VHF and UHF and I'm one of them.

Foliage absorbs and scatters such signals as do building materials which is why an outdoor antenna works better than the same one indoors. The problem gets worse as the frequency goes up, I'm sure you've seen the commercials where the cable companies say satellite sucks. They're right in one regard, unless the dish has a clear shot at the bird anything in the way obscures the signal and that includes heavy weather, the weather radar operates on this principle.

"There are lots (I mean lots) of Southern Pine up there, ever notice how long those pine needles are?"

Lou, if you took the time to measure them you'd probably find them to be resonant on UHF. That may be a tongue in cheek remark but I'm probably right.
 
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N_Jay

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kb2vxa said:
. . . .

"There are lots (I mean lots) of Southern Pine up there, ever notice how long those pine needles are?"

Lou, if you took the time to measure them you'd probably find them to be resonant on UHF. That may be a tongue in cheek remark but I'm probably right.

That's the rumor, but I doubt it matters.

What does matter is the amount of water in each needle to absorb energy.

Higher frequencies are absorbed more. No magic about wavelength and needle length.
 

fineshot1

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I also doubt very much if foliage matters much at most of the frequencies we monitor via our scanners. I dont remember where I read it but I once read a doc on " RF Foliage Absorbtion " and it stated that this is barely measurable until you reach about 3 or 4Ghz. I use the 1.2ghz band alot and have never noticed any difference between winter & summer time propagation. The only thing I ever noticed that effected propagation at 1.2ghz was thick fog or mist in the air and even then there had to be lots of it......
 
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N_Jay

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fineshot1 said:
I also doubt very much if foliage matters much at most of the frequencies we monitor via our scanners. I dont remember where I read it but I once read a doc on " RF Foliage Absorbtion " and it stated that this is barely measurable until you reach about 3 or 4Ghz. I use the 1.2ghz band alot and have never noticed any difference between winter & summer time propagation. The only thing I ever noticed that effected propagation at 1.2ghz was thick fog or mist in the air and even then there had to be lots of it......

Foliage does affect propagation. There are even standard values to use to adjust coverage studies between seasons.
 

mancow

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It makes a huge difference when working with weak signals.

You can really tell the difference when working with body wires out in the County. In the winter you can get quite a bit of distance away and hide. In the humid summer months with heavy foliage it doesn't take much vegetation to really attenuate the signal.
 

fineshot1

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N_Jay - The question is " how much " , not does foliage effect propagation. Yes - it does effect propagation, but at the frequencies and signal levels most of us use whether with an indoor or outdoor antenna it is doubtfull that anyone in that situation is going to be able to measure the difference. Now if you want to do a scientific analysis using all kinds of nice measuement gear yes you will be able to measure the effect but its going to be a small amount.

mancow - We are generally not talking about week signal here. Most of the general scanner users are listening to local or semi-local signals. Some scanner users trying to listen to signals far off use yagis or preamps or combos of the two.
 
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N_Jay

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fineshot1 said:
N_Jay - The question is " how much " , not does foliage effect propagation. Yes - it does effect propagation, but at the frequencies and signal levels most of us use whether with an indoor or outdoor antenna it is doubtfull that anyone in that situation is going to be able to measure the difference. Now if you want to do a scientific analysis using all kinds of nice measuement gear yes you will be able to measure the effect but its going to be a small amount.

mancow - We are generally not talking about week signal here. Most of the general scanner users are listening to local or semi-local signals. Some scanner users trying to listen to signals far off use yagis or preamps or combos of the two.

How much depends on how much foliage and how much margin you have.

Saying it is a little or a lot is meaningless.

It is enough to have to be considered when developing coverage acceptance tests for systems.
 

loumaag

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Okay, I have been away from this for a bit so I will just throw this out there.

No, I was not being "tongue-in-cheek". After trying UHF in the St. Tammany and Tangipahoa parish areas, it was found that it had very little coverage. Since VHF worked as did 800 MHz, the blame was laid on pine needles. With needles running from 5 to 9 inches, and when on the tree full of pine sap, I think one might consider that they may indeed make pretty good RF attractors.

So I guess a sap filled 6 1/8 inch pine needle would make at least a passable absorber, now lets see, multiply that by ... oh a couple of billion or so and you see UHF doesn't cut it. Now I don't know about where you live fineshot, but in that area, they don't use UHF because of it.
 

fineshot1

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Lets see if I can get all these quotes right - if not sorry about that.

kc8qln said:
In even more general terms, does foliage reduce the ability to receive
signals?

Please reread the above question - I never challenged the concept that
foliage does not reduce the ability of one to receive signals, only the
matter of whether a scanner listeners ability to notice the difference
between normal winter & summer propagation(excluding ehancements).

N_Jay said:
There are even standard values to use to adjust coverage studies between seasons.

Thank you N_Jay for pointing that out. Yes there are standard values used to
make those adjustments between seasons. Its been many years since I used
these but as I recall they were very small amounts. Some of those adjustment
tables were developed for the early wireless carriers in the early days of analog
cellular in the 800Mhz bands when cell sites were spaced very far apart and they
needed to squeeze every mile/kilometer of coverage they could. I have not worked
in that industry in a few years but I am sure not much has changed as far as the
propagation modeling.

N_Jay said:
How much depends on how much foliage and how much margin you have.

Saying it is a little or a lot is meaningless.

It is enough to have to be considered when developing coverage acceptance tests for systems.

I disagree about it being meaningless when you consider the original question.
kc8qln is wondering if he will notice a difference between winter & summer
propagation while monitoring mostly ( i assume ) local comms in his area.
I expressed my doubts if he would considering the seasonal adjustment is
relatively small. Most listeners have difficulty noticing a 3db drop in signal
if they are monitoring local signals which are usually strong. The adjustment
values are usually much smaller than 3db locally.

loumaag said:
Since VHF worked as did 800 MHz, the blame was laid on pine needles.
With needles running from 5 to 9 inches, and when on the tree full of
pine sap, I think one might consider that they may indeed make pretty
good RF attractors.

So I guess a sap filled 6 1/8 inch pine needle would make at least a
passable absorber, now lets see, multiply that by ... oh a couple of
billion or so and you see UHF doesn't cut it. Now I don't know about
where you live fineshot, but in that area, they don't use UHF because
of it.

I also live in a pine rich area( NJ Pine Barrens ) and much of the propagation
around here depends on how well the system gets engineered. Our system is
mostly UHF and works well. In fact on some of the scanner threads its been
refered to as " a flame thrower " due to the fact that lots of listeners have been
able to copy the trunk sys & paging via there scanners from a few counties away.
You did not mention any of the engineering aspects of the systems in your area
so I cannot comment on them.
 

AVL

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i too live in a area where their are alot of trees i use an outdoor attenna and until i get rid of my trees the foilage will block scatter my signals but i do receive alot of my out of town freqs in warmer weather
 

loumaag

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fineshot1 said:
I also live in a pine rich area( NJ Pine Barrens ) and much of the propagation around here depends on how well the system gets engineered. Our system is
mostly UHF and works well. In fact on some of the scanner threads its been
refered to as " a flame thrower " due to the fact that lots of listeners have been
able to copy the trunk sys & paging via there scanners from a few counties away.
You did not mention any of the engineering aspects of the systems in your area
so I cannot comment on them.
Sorry for the delay in addressing your reply, I either didn't get a notification or missed it, but saw it based on the most recent post.

It is not "my" area. I live in Houston at the moment, and I was not privy to the engineering data available at the time, but I can assure you, since the UHF equipment was being donated, if they could have made it work, they would have. This was along the North Shore of Lake Pontchartrain in SE Louisiana more than a decade ago. I have also lived in the NE (1970's) and traveled in NJ extensively; the Pine Barrens is aptly named when compared to that area of LA.
 

kb2vxa

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Hi again,

No Lou, 'twas ME who was being tongue-in-cheek, tongue isn't all that fills a HAMster's pouches you know. (Most of the time it's the nuts and it's NOT what you're thinking!)

"That's the rumor, but I doubt it matters."
That's why mine was a qualified statement, you overlooked the "maybe".

"What does matter is the amount of water in each needle to absorb energy."
It matters to a microwave oven too which leads me to the FCC's RF exposure rules.

"Higher frequencies are absorbed more."
I already said that, read on.

"No magic about wavelength and needle length."
Not magic, science. That's the basis of the exposure frequency vs. power and distance from the antenna formula, different body parts resonate at different frequencies. Since they average out to around 300MHz that's where the most stringent limits lie.

Oh Fartshot, (;->) since the Pine Barrens were a vast shallow bay in prehistoric times and today they're low rolling sand dunes, otherwise flat land ANY transmitter in SOC may be considered a flame thrower. I wonder if the bog iron deposits and all those shallow recreational lakes and cranberry bogs have anything to do with it, hmmm. (;->) I'll bet signals are hot over the Pygmie Pines around Warren Grove, heck, I'm taller than they are. Speaking of Warren Grove, keep your eyes on those F-16s, they're known to start forest fires in Bass River with off target practice bombs and strafe schools in Stafford.

No guys, I'm NOT kidding! Frankly I'd like to hang the jerk who blew out my windows with a freakin' MOAB and so would the cop who jumped out of his skin way over on Polypod out in Eagleswood. Yup, we have the NJANG they used as a model for the movie The Gang That Couldn't Shoot Straight, Tim Conway and Don Knotts must have been pilots.

One final and somewhat humerous note on southern Ocean County, oxycoccus is the Latin genus for cranberry. It may sound like a drug but it's a school in Stafford Twp. (not the one they strafed). I can just picture Thanksgiving turkey and oxycoccus sauce, WOOEE! That'll raise the question of what's in the stuffing but you'll just have to find the answer in the next issue of Weird New Jersey.
 
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k9rzz

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kc8qln said:
Generally speaking, when all the leaves fall, do you hear father?

In even more general terms, does foliage reduce the ability to receive signals?

Thanks

To answer the direct question though, "Do you hear further in winter?" I would say NO. You may have less losses due to trees, but the VHF and UHF band conditions are flatter with respect to tropo enhancement.

Generally speaking, unless you have an opening, you will hear further in summer than in winter. Winter time is pretty boring, DX-wise.

John K9RZZ
 
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