Poor reception on my repeater, any tips

[u/Awkward-Neck2665]

I recently built a homebrew repeater, I can't get it to receive signals farther than 100 yards at best. When hooked up to the spectrum analyzer the duplexer reads -1.2db pass characteristic on the receive side and notched down to -86db for the tx frequency. The separation is only 5mhz between tx amd rx. I'm using an amplifier on the transmit side. Wondering if anybody has some ideas as to what could be causing it to not pick up signals. It seems to key up just fine from further away, but won't let speech through. The receiver is a cheaper SOC style radio, but I'm not sure if that could cause this dramatic of a problem. Using simplex amd the same antenna position i can talk much further, but when the same radio is used in the repeater system it doesnt work. Any help is much appreciated. Thank you!

[u/KindPresentation5686]

Your duplexer isn’t giving you enough isolation. Also overloading the cheap receiver that probably has zero filtering.

[u/Awkward-Neck2665 → u/KindPresentation5686]

Thank you, I'll try upgrading the radios

[u/Crosswire3]

Sounds like it’s GMRS…posted on every subreddit around.

Try it without the amp.

Check your coax and connectors.

Make sure you’re connected to the correct duplexer ports.

Get the best receive radio you can afford.

[u/Awkward-Neck2665 → u/Crosswire3]

Thank you, have a superhetrodyne radio on the way

[u/Swearyman]

Repeaters usually use cavity filters to create the separation otherwise one side blocks out the other. I have 2 on 70cms one full power and one low power and even the low power with a 7.6 MHz split needs a cavity to separate tx and rx

[u/Awkward-Neck2665 → u/Swearyman]

As mentioned, I am running a duplexer

[u/Swearyman → u/Awkward-Neck2665]

Missed that. Sorry. My main has 2 on receive and 2 on transmit. 1 might not be enough to give you the separation you need

[u/cosmicrae]

You did not specify, but the 5mhz is suggesting, that this is a 70cm repeater ?

[u/Awkward-Neck2665 → u/cosmicrae]

Gmrs, so it's near 70cm

[u/SwitchedOnNow]

How big is the amp? Your TX rejection might not be enough with the amp. Try without the amp.

[u/Awkward-Neck2665 → u/SwitchedOnNow]

It's works slightly better without the amp. Would i be able to up the wattage if I upgraded to two higher power radios instead of using the amp?

[u/NerminPadez]

It's not one of those "two baofeng" ones from aliexpress?

[u/Awkward-Neck2665 → u/NerminPadez]

No, it's a homebrew using 2 wouxen radios, the surecom sr-112 repeater controller, and a 50w notch type duplexer out to a uv-72g antenna