Quantar repeater sounds like heterodyning
Posted: Wed Sep 23, 2015 12:56 pm
Hello folks,
Got a Quantar repeater that sounds like there's heterodyning going on on the TX side. Only happens when a subscriber keys the repeater, I don't get the interference when I front panel key the repeater, and there's nothing audible except for noise floor when I unsquelch the receiver.
The Quantar is setup for mixed-mode, and I don't have access to the codeplug for the subscribers, which are XTL and XTS series. I'm 75% certain the subscribers are operating in analog, as there's paging happening, and pagers setup to RX from this repeater.
I disconnected the RX antenna and threw a load onto the receiver, with no change in results. Swapped power supply and receiver and for a few days traffic was passing, but the hang time was still howling.
Suspects are audio processing circuitry on the control board, possibly hear clear / companding going on.
Come to think of it, I need to try turning companding off...
Any thoughts on what would make a Quantar howl like it's heterodyning?
Got a Quantar repeater that sounds like there's heterodyning going on on the TX side. Only happens when a subscriber keys the repeater, I don't get the interference when I front panel key the repeater, and there's nothing audible except for noise floor when I unsquelch the receiver.
The Quantar is setup for mixed-mode, and I don't have access to the codeplug for the subscribers, which are XTL and XTS series. I'm 75% certain the subscribers are operating in analog, as there's paging happening, and pagers setup to RX from this repeater.
I disconnected the RX antenna and threw a load onto the receiver, with no change in results. Swapped power supply and receiver and for a few days traffic was passing, but the hang time was still howling.
Suspects are audio processing circuitry on the control board, possibly hear clear / companding going on.
Come to think of it, I need to try turning companding off...
Any thoughts on what would make a Quantar howl like it's heterodyning?