There is an audible click once per second when receiving analog FM audio that is just below full quieting. It is not as noticeable on very strong signals, nor on very weak ones. It is worst on 2M FM and can also be heard on weak signals in the FM broadcast band. Less noticeable on 440 but can sometimes be heard a bit.
When the time display is enabled, the click is synchronized with the colon blinking on and off in the time display.
If you place another radio next to the AnyTone and turn down the AnyTone's audio, the click can be heard in the other radio's received audio in the same conditions.
Some owners have reported that turning off the time display fixes the problem, but I found no difference in my radio when I tried this.
A longer click - or more of a chop sound - can be heard when navigating through the radio menus under the same conditions.
It seems clear what is happening: the radio's CPU is emitting some EMI/RFI when it runs. Like most battery powered devices, the CPU spends most of its time in a low power sleep state. But it wakes up in response to any interrupt: any button press, knob rotation, or on a timer that fires once per second.
The ultimate fix for this will have to be a hardware revision. But it seems likely that a partial fix could be accomplished in firmware.
Does the CPU really need to wake up every second? No one cares if the ":" in the time display blinks, so there is no reason to wake up the CPU just for that. Are there other display updates that require an update every second?
It seems that a simple fix could be to just not wake up the CPU so often. For example, a click once every five seconds would be much less annoying than a click every second.
Hardware 1.10, firmware 2.27
There is an audible click once per second when receiving analog FM audio that is just below full quieting. It is not as noticeable on very strong signals, nor on very weak ones. It is worst on 2M FM and can also be heard on weak signals in the FM broadcast band. Less noticeable on 440 but can sometimes be heard a bit.
When the time display is enabled, the click is synchronized with the colon blinking on and off in the time display.
If you place another radio next to the AnyTone and turn down the AnyTone's audio, the click can be heard in the other radio's received audio in the same conditions.
Some owners have reported that turning off the time display fixes the problem, but I found no difference in my radio when I tried this.
A longer click - or more of a chop sound - can be heard when navigating through the radio menus under the same conditions.
It seems clear what is happening: the radio's CPU is emitting some EMI/RFI when it runs. Like most battery powered devices, the CPU spends most of its time in a low power sleep state. But it wakes up in response to any interrupt: any button press, knob rotation, or on a timer that fires once per second.
The ultimate fix for this will have to be a hardware revision. But it seems likely that a partial fix could be accomplished in firmware.
Does the CPU really need to wake up every second? No one cares if the ":" in the time display blinks, so there is no reason to wake up the CPU just for that. Are there other display updates that require an update every second?
It seems that a simple fix could be to just not wake up the CPU so often. For example, a click once every five seconds would be much less annoying than a click every second.