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Newbie KG-1000G Plus user


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Posted

Y'all take it easy on me. lol. I've read most of the stickies pertaining to why most new GMRS users immediately want to jump into having a repeater. Guess that's me. Good or bad. Can someone explain to me why I'm not showing the TX icon on my TX transceiver but showing the RX icon on my RX transceiver? Thanks WRXU693

14 answers to this question

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Posted
26 minutes ago, JamesBrox said:

Y'all take it easy on me. lol. I've read most of the stickies pertaining to why most new GMRS users immediately want to jump into having a repeater. Guess that's me. Good or bad. Can someone explain to me why I'm not showing the TX icon on my TX transceiver but showing the RX icon on my RX transceiver? Thanks WRXU693

Maybe because it’s not transmitting until it actually receives something with the right tone?

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Posted

On the input tone, as @Sshannon suggested, you may try setting the speaker to "on" on the receiving radio, so you can at least hear if it's receiving the audio.

From there, the other thoughts that come to mind are the connection cable between the radios, and the configuration on the radios themselves...are they set properly for their place in the setup, especially the tx radio.

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Posted

Or, spend $800 to $1000 and get a purpose built repeater with a decent receiver front end that won't desense, and cooling fans to boot.

Public Service announcement: your "50 watts" won't perform any better than a properly configured 10 watt repeater when you are talking back in with 5 watt portables. Especially if you're talking through a cheap compact duplexer that's probably rated at 65 or 70 dB isolation (and that's when it's properly tuned).

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Posted

"Public Service announcement: your "50 watts" won't perform any better than a properly configured 10 watt repeater when you are talking back in with 5 watt portables. Especially if you're talking through a cheap compact duplexer that's probably rated at 65 or 70 dB isolation (and that's when it's properly tuned)."

 

That's like the number 1 thing I try to get people to understand when they get into radio. Power out of the repeater has nothing to do with talk in range (if desense is out of the picture). 

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Posted
11 hours ago, Radioguy7268 said:

Or, spend $800 to $1000 and get a purpose built repeater with a decent receiver front end that won't desense, and cooling fans to boot.

You get what you pay for. Some find out the hard way why something is so cheap.

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Posted

Yeah, but the desense issue is huge with a compact duplexer. Even when properly tuned, if you over-power the transmit side, you are still introducing a weak but competing signal on the receive side that WILL reduce the talk-back range of your portables. Worst of all, your own equipment is what's producing the interference, and you probably paid more money to get all that interference!

 

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Posted
21 minutes ago, quarterwave said:

Especially if you're talking through a cheap compact duplexer that's probably rated at 65 or 70 dB isolation (and that's when it's properly tuned)."

That's more important than you think. Remember one of the functions of a duplexer is to "isolate" the RX and TX sections since they are both using the same antenna. A receiver can only tolerate a small level of signal before the AGC, automatic gain control, in the radio reduces the internal signal level to keep it within the operating range of the electronics. The gain can be reduced to the point were a weak signal is reduced to a level where the FM detector can't work. That's desense in action. As strange as it sounds some repeater owners discovered that REDUCING transmitter power improved the receiver sensitivity!

Why is that? Well consider the duplexer has a FIXED attenuation. Those cheap Chinese duplexers don't have a lot to begin with anyway. So if the transmitter power is increased the signal level feed into the receiver's front end increases too.  As I mentioned if it gets too high then the AGC kicks in big time and your receiver goes deaf. That's why higher power repeaters use duplexers with 100db or more isolation. They have to use it to keep the signal level into the receiver below the point were desense occurs.

Finally if the repeater is installed at a site with a bunch of other high power transmitters, which are in close proximity, all that power is trying to get into your repeater's receiver too. The duplexer has to keep all that crap out as well.

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Posted

Oh, one other important point that very seldom gets mentioned is the quality of the coax cable. I'm NOT talking about signal loss in the cable. Coax cables are not perfect and will leak a little RF along their length. When your TX and RX cables are in close proximity signal leakage from the TX side coax can get into the repeater's receiver section AFTER the duplexer. That sort of defeats the whole purpose of using one.

Smart repeater builders will use multiply shielded coax cable for this exact reason. Yeah, it might be more expensive, but it's the difference between a great performing system verses a poor one.

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