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Question on Repeater and Oscillation


prophead

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I am sure there are alot of folks on this site that know alot more about wireless networks than I do, so hopefully those experts can give me a bit of advice....

 

I have an useable (barely) 800 signal in my house but the 1900 signal simply does not work inside. This creates a bit of a problem if you're on a call outside on 1900 and enter the house.

 

I had an old zBoost YX500 PCS I decided to install to boost the 1900 signal to prevent the call from dropping when entering the house. The external antenna is a 13DB Directional antenna (YX-023).

 

The instructions say to prevent Oscillation (and therefore reduced performance) there should be a minimum of 15' of VERTICAL speration between the external and internal antenna.

 

The issue I have is that if I place the antenna with the 15' of vertical seperation I will have a tree between the antenna and the tower producing the strongest signal.

 

I've thought about placing the antenna on the tree trunk but that would be on the same plane as my internal antenna athough the horizontal seperation will be about 45' with an interior wall and an exterior wall (with a window) between the two antenna's.

 

If Oscillation is happening the repeater will simply reduce output kind of defeating the purpose.

 

So the questions for the experts....

 

How good is a direction antenna at preventing Oscillation? Am I better off mounting my antenna lower where there is a risk of Oscillation or higher where that risk is reduced but a tree (bare now, but a very dense leaf canopy in the summer) is between the strongest tower and my antenna?

 

 

 

 

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I am sure there are alot of folks on this site that know alot more about wireless networks than I do, so hopefully those experts can give me a bit of advice....

 

I have an useable (barely) 800 signal in my house but the 1900 signal simply does not work inside. This creates a bit of a problem if you're on a call outside on 1900 and enter the house.

 

I had an old zBoost YX500 PCS I decided to install to boost the 1900 signal to prevent the call from dropping when entering the house. The external antenna is a 13DB Directional antenna (YX-023).

 

The instructions say to prevent Oscillation (and therefore reduced performance) there should be a minimum of 15' of VERTICAL speration between the external and internal antenna.

 

The issue I have is that if I place the antenna with the 15' of vertical seperation I will have a tree between the antenna and the tower producing the strongest signal.

 

I've thought about placing the antenna on the tree trunk but that would be on the same plane as my internal antenna athough the horizontal seperation will be about 45' with an interior wall and an exterior wall (with a window) between the two antenna's.

 

If Oscillation is happening the repeater will simply reduce output kind of defeating the purpose.

 

So the questions for the experts....

 

How good is a direction antenna at preventing Oscillation? Am I better off mounting my antenna lower where there is a risk of Oscillation or higher where that risk is reduced but a tree (bare now, but a very dense leaf canopy in the summer) is between the strongest tower and my antenna?

You normally want the antenna to be as high as possible. it will grab a better signal.  But you may have a unique situation.

Just slightly more than 15 feet separation will help.  Directional antennas help.    Try to NOT go so many feet away that the loss in the Coax kills the weak signal.  Try going 20 or 25 feet away if possible. Vertical separation is normally better than horizontal separation.

 

Place the directional antenna so it is closer to the cell site than your repeater.  You want the transmitted signal to go towards the cell site but not over the repeater in the living area.

In normal conditions, when you have a 1900 signal that is marginal, any 800 signal from the same tower will be satisfactory.  But the calls do drop when the 1900 signal fails as you walk inside.

 

Those old zBoost repeaters are not the total answer.  They can help a little, but do not expect to see all issues disappear. You never get the advertised range in your living area.  When you walk into the house, if it stays connected, get near the repeater so you stay connected.

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If the inside antenna is also directional as long as they are both outside of each other radiation area they should not oscillate. A simple example would be a outside antenna and an inside antenna on the same pole with at least 3 feet of separation one pointed in one direction and the other 180 degrees in the opposite direction, they should not oscillate as they wouldn't radiate on each other to oscillate.

 

With an onmidirection antenna everything on the plane parallel to the base of the antenna and opposite to where the antenna protrudes would free of radiation from the omnidirectional antenna as long as the directional outside antenna is pointed away from the radiated area.

 

My understanding on antennas and radiation is limited but that is what I have found in my experience. If you can find a radiation map for each antenna it should help you with placement somewhat. Please anyone correct me if I am wrong.

Edited by miguell2
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I just ran a custom PRL that prioritized 1x800 until Sprint fixed the call drop issue by allowing for soft handoffs between 1x1900 & 1x800. Hopefully they will soon make the necessary upgrades at your local MSC to permit such handoffs in your area as well. Macro-to-WiFi handoff (like T-Mobile can do) would also be useful.

 

I've unfortunately no idea if it is possible to write a custom PRL to a flip phone, but it may be cheaper to get a cheap smartphone and flash one to it than buying another repeater.

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I've unfortunately no idea if it is possible to write a custom PRL to a flip phone, but it may be cheaper to get a cheap smartphone and flash one to it than buying another repeater.

 

It is possible....I have done it....the only problem is the 800 signal, while great outside is also a little weak inside. This is a house with aluminum siding. :(

 

An 800 MHZ repeater that supports the SMR band would be ideal.

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