XPR8400 Repeater, no distance when trying to use as mountaintop

[lwadsworth]

Hello trbo experts. I have attempted this a few different times and I am at a loss.

I have a command center. In the command center I have a stack of 3 xpr8400's with three duplex channels. I run a Comprod filtering system and a 5.5db gain die pole antenna. And it works great. However today I am caught in a situation where it doesn't reach far enough and I need to take a repeater out and put it on a mountain top. I have a duplexer, generator power and an omni directional antenna. However I get not range with it. 1.8km is as far as I can go from the repeater and it will not repeat any further either.

I have tried two different frequency pairs with corresponding duplexers.

170.775 & 173.775
153.335 & 158.305

I did some googling last night and read that a standard flat duplexer will not filter enough to help. Is that what I am doing wrong, is this an impossible feat? Or is it something super simple that I am missing?

You can email me and I can send pictures of my set ups if anyone would like. LAW429@gmail.com

 

[buddrousa]

#1 What type antenna and gain are you using.
#2 You may have introduced a higher noise level in the receiver or someone else using the same input.
#3 Or you are over shooting your area.
#4 Or a combination of all three.
#5 Are these the same duplexers you used at the other site and did you tune them for the system they are on?

 

[lwadsworth]

Hi there and thanks for the response and interest.

I am using a sinclabs omni for 138-174 MHz which boast 3db of gain.
The frequencies I am using a registered with industry canada for western Canada so I should be good, I hope anyways.
What do you mean by overshooting?
In the trailer I use filters as I am running 3 repeaters. When I disable one I then need to use a duplexer for the field use as these filters ain't moving. I then use the RX filter to bring in from the repeater to the control radio to get the data.
The duplexers are tuned accordingly.

 

[lwadsworth]

Is it possible to put pictures in here?

 

[RKG]

No one has mentioned duplexer tuning.

 

[kayn1n32008]

Hello trbo experts. I have attempted this a few different times and I am at a loss.



I have a command center. In the command center I have a stack of 3 xpr8400's with three duplex channels. I run a Comprod filtering system and a 5.5db gain die pole antenna. And it works great. However today I am caught in a situation where it doesn't reach far enough and I need to take a repeater out and put it on a mountain top. I have a duplexer, generator power and an omni directional antenna. However I get not range with it. 1.8km is as far as I can go from the repeater and it will not repeat any further either.



I have tried two different frequency pairs with corresponding duplexers.



170.775 & 173.775

153.335 & 158.305



I did some googling last night and read that a standard flat duplexer will not filter enough to help. Is that what I am doing wrong, is this an impossible feat? Or is it something super simple that I am missing?



You can email me and I can send pictures of my set ups if anyone would like. LAW429@gmail.com

I am somewhat local to you, and I have sent an email to you.


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[ramal121]

Yea, first thing I'd say is the duplexers are way outta whack to knock you down that much. Do you have the cables hooked up correctly? Jeez never done that before myself. Also if the antenna is too close any mediocre repeater it will desense and limit your range. Using RDAC from the software package can tell a lot.

Need a qualified radio tech to scope it out.

 

[kayn1n32008]

The OP emailed me photos. Not the ideal set up. Ts poertable. Antemma is a 1/2wave about 2.5m above ground. Going to check out, with the OP and get some specs on cabling, duplexer, and feedline. Runnng off a inverter generator... its a temp setup... just on the fly and not ideal situation. Hopefully we can get some positive results for the OP

 

[ramal121]

Bully for kayn1n32008. Report back...

 

[kayn1n32008]

Bully for kayn1n32008. Report back...

I always pay attention to what you write ramal121, your advise is always spot on.

It's defiantly not the ideal set-up. Hopefully we can get it working better than it is. The 1/2wave mobile antenna 2.5m above ground, coupled with unknown feedline, along with unknown jumpers between repeater and duplexer, is likely his biggest hurdle. Not a fan of the generator, but it may be all he has on hand at the moment.


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[kayn1n32008]

Bully for kayn1n32008. Report back...

PM sent


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[kayn1n32008]

Update: looks like it is going to be a combination of single shield jumpers, and antenna feedline. Coupled with low antenna elevation. Working offline with the OP to get him on the right track.


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[kayn1n32008]

Bully for kayn1n32008. Report back...

PM read. Check your email.

 

[kayn1n32008]

Update: well, looks like he is on the right track. lwadsworth is a quick learner! The deployment it was on is done. Got him making some good changes... Seems his local radio shop is fond of RG-58...