Repeater help..

[Drake1731]

Hello. So I have a duplex repeater setup, and I have an issue. So I have 2 Wouxun KG-UV920Ps with the repeater cable. I have them both connected correctly, everything it setup, etc. Then I have 2 Baofeng 888's acting as a small duplex system as well. The Baofengs have a small repeater controller connect to each of the accessory ports. I try out the repeater, on UHF 400-470. And not a lot of luck. For both. I can go further with no repeater than with one. The KG-UV920Ps were set to 10 watts for testing purposes, and the baofengs, to my knowledge at 5 watts. The KG-UV920Ps have the same antenna, and are setup correctly, but it doesnt make since to me that talk around goes further than a repeater.. Any help? If you need anymore information, I'd be glad to provide it.

 

[MTS2000des]

Hello. So I have a duplex repeater setup,

Are you using an in-band (UHF TX and RX?) No duplexer, separate antennas? Are they far enough apart to avoid desensing each other? For any duplexed system to work well, adequate TX/RX isolation is a must. Otherwise you're transmit is wiping out your receive.

Transmitting at the same time one is receiving, especially in the same RF sub band, requires filtering for such a system to work. What kind of filtering are you using in your setup?

 

[Drake1731]

Are you using an in-band (UHF TX and RX?) No duplexer, separate antennas? Are they far enough apart to avoid desensing each other? For any duplexed system to work well, adequate TX/RX isolation is a must. Otherwise you're transmit is wiping out your receive.

Transmitting at the same time one is receiving, especially in the same RF sub band, requires filtering for such a system to work. What kind of filtering are you using in your setup?

I'm using UHF TX and RX, no duplexer, and seperate antennas. The KG-UV920P repeaters antennas are not even close to being far apart, I should know better. The other repeater with the baofengs are a pretty good distance apart. I have no filters. Sounds like my system has a load of flaws. Thanks MTS. Also, can you help me program my trunking radio? LOL just kidding.. ("NO I will not help program your trunking radio.")

 

[MTS2000des]

I'm using UHF TX and RX, no duplexer, and seperate antennas. The KG-UV920P repeaters antennas are not even close to being far apart, I should know better.

There's your problem. If you aren't using a duplexer, and run separate TX and RX antennas, spacing is critical. It's also recommended they be mounted at different elevation to avoid interaction. Also, keep in mind your mobiles are TXing with many times more power than the portables.

I am not sure how great the selectivity is on the Chinese mobiles, but my guess is based upon my experience with the portables, it isn't anywhere near what a high quality LMR radio would have, so keep this in mind.

If you want a good quality repeater in-band, a good quality duplexer, feedline, and antenna are the only way to fly.

I would recommend using a cross band (V/U) setup. Does the UV-920P not have this feature? you have dual band portable radios. This would mean using only a single dual band antenna, one feedline, and pretty much eliminate TX/RX interaction issues due to the frequency spacing involved.

Also, can you help me program my trunking radio? LOL just kidding.. ("NO I will not help program your trunking radio.")

You would be surprised how many people ask stuff like that.
The only ones who get that wish granted are the ones who show up at my office in a uniform with a letter in hand from their superior or an email in my work inbox.

 

[cmdrwill]

And Baofeng and some waxon adios have a lot of noise on the transmitter, and are not suitable as repeater transmitters.Even with proper filtering they are bad.