Why are some frequencies "live" where is nothing

Question

I was ham surfing on the 2 meter FM band on my C Crane 2E Radio and occasionally I come across these frequencys that are "live" but no Audio came through.

The way I know that a frequency is dead is that their is static, when a round table or someone drops out the frequency goes out and static comes in.

Im listening to one it has static hiss in the background with some static the reception bar read about 1/3rd.

So why do these frequencys appear to have a carrier going but nothing is their or am i miss interpreting this as good reception.

It could be lots of things. It could be someone testing, it could be an AM carrier that's far enough away you only hear the carrier but not the sidebands. It could be a non-ham transmission. It could be a signal from a piece of equipment or computer or device around your home or neighborhood. Hard to say. — Duston, Mar 06 '20 at 14:56
Why do you think there is a carrier? Just because the static is louder does not mean there is any signal or carrier. The mode of the receiver may change how the the static is demodulated, even without a real signal. — user10489, Mar 07 '20 at 23:53
This question needs more details. What mode are you on, AM? It sounds to me that you are listening around 7285, where a lot of AM is. — Mike Waters, Mar 08 '20 at 00:28
*There is no 40 meter FM band*. You don't have [one of these radios](https://www.eham.net/forum/view?id=topic=17222;msg=96921), do you? — Mike Waters, Mar 08 '20 at 02:52
They could be spurious signals generated within the radio or without. — vu2nan, Mar 14 '20 at 07:31

score 1 · Answer 1 · answered Mar 16 '20 at 11:32

Probably you are seeing the results of the AGC on your radio adjusting the front end gain of your radio between when there is no signal and when there is a strong signal.

Just because you hear static does not mean that there is a carrier. It just means that your radio is trying very hard to find a signal and has demodulated noise into white noise. If this bothers you, adjust the squelch on your radio, or if you are listening to a repeater that transmits it, enable tone squelch.

Why are some frequencies "live" where is nothing

1 Answers1