800MHz high gain range

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Evnldr

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Is there some chart that shows how high and what db gain is needed for what distance?

I'm looking for a distance of about 35 miles looking at a directional if needed.

Currently using a RS discone and I'm about 10 miles or so.. A station 10 miles I'm getting 2 bars
Its about 15ft high.

I was looking a directional 9db gain antenna

Thanks.

Something like this maybe Wilson Electronics Yagi Model Y8900EL
 
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robertcansler

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what type terrian are u in ???
Do you know approx the power the service is using. just because the radios will put out 8 watts they may be set lower as not to inter with someone else. all of this can affect what you are looking for


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Evnldr

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Not sure, It's Philadelphia County. and im like 35 miles away. not sure the terrain maybe some hills..
Its from Newark DE to Philadelphia County PA. I have looked tor a terrain map.
 

mmckenna

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800MHz is very line of site.

It will penetrate buildings well, but hills won't happen.
Knowing the height of the transmitting antenna will play into the line of site calculations, also, your antenna location will, too.

Then you can look at things like feed line loss, etc. Once you have that, you can figure what your antenna gain needs to be.


Or, just try it and see if it works. 35 miles isn't an issue on it's own. I've been 60 miles from my system with a clear line of sight. This was a mobile install with a quarter wave antenna on top of a truck.
 

Audiodave1

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Hello neighbor,
Are you looking to pick up Philly's 800 system?
If so, that will be a stretch based on my previous experiences from the I95/202 area with up to 13dB of YAGI.

Dave
 

mmckenna

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You think a Y8900EL OR A 301111 would work much better than a discone?

Absolutely, yes.

Discone antennas have zero gain. A Yagi directional antenna for 800MHz can easily have 9dB gain or more. That's a pretty big difference.

However, if the signal isn't there, no amount of antenna gain is going to magically make it appear. You've got to have something to work with.
 

Jimru

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You think a Y8900EL OR A 301111 would work much better than a discone?



Discones are not gain antennas. The two things they have going for them are a wide range of frequencies bands received and they are omnidirectional, but no gain.
 

robertcansler

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I dont thinknyour going to find what you are looking for in a single chart. to many varianles on the technical side. power of xmitter terrian trunkef non yrunked urban area metronarea etc. put your antenna as highbas u can use low loss coax. i am lucky my antenna is approx 78 ft in the air on a telephone pole I am 472 feet above sea level. i hear all of south carolina palmeto system
most of southern north carolins parts of georgia of course being on a dairy farm is perfect. no obstacles


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N8IAA

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Yea, I was looking for a chart to see how far 800mhz travels

Something to remember, Phase II signals are much lower power than Phase I, which is lower than the old analog trunking.
So, even with a gain antenna, your chance of hearing that distant signal is not good.
HTH,
Larry
 

teufler

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800 RANGE

ON MY mOTOROLA 2 WAY RADIO CALCULATOR, SAY YOU ARE 35 MILES, AND THEY ARE RUNNING 100 WATTS, YOU HAVE A 9DB GAIN ANTENNA, YOU HAVE TO HAVE 300FT OF A TOWER OR ELEVATION OVER THE OTHER STATION. I AM 35 MILES TO DOWNTOWN ST LOUIS AND THEY ARE HARD TO PICK. NIGHTTIME HELPS BUT DAYS ARE FAR A FEW BETWEEN.
 

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kayn1n32008

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What folks are not including here are the many variables to each system. No 2 systems are the same.

Some variables that will be encountered:

Antenna height above ground
Transmission line loss
Power output
Effective radiated power
Antenna gain
Antenna pattern
Local terrain

Saying Phase 2 transmits with less power than phase 1 and phase 1 transmits with less power than analogue is plain wrong to assume. The only way to know is to look at at actual licensed power output.
 

kayn1n32008

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Something to remember, Phase II signals are much lower power than Phase I, which is lower than the old analog trunking.

So, even with a gain antenna, your chance of hearing that distant signal is not good.

HTH,

Larry



Uh nope. All dependant on individual licenses. A blanket statement like that is not accurate.
 

ko6jw_2

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Use Google Earth. Use the ruler tool to draw a line from your location to the desired site(s). Make an elevation profile. You will see the path to the transmitter. If there are a lot of hills or obstructions you are probably out of luck.
 
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