tvengr
Well Known Member
Before you reload firmware, try resetting the global settings to factory defaults. Turn the scanner off. Turn the scanner on. At the Welcome screen, press 0 and then press 2. That will not erase your programming.
How well does aircraft monitoring work? Unfortunately, I don't have a schematic for the scanner. If it does use diodes for band selection, a high RF level is not going to fry a band selection diode where it is located in the circuit. Some scanners use varactor diodes (variable capacitance controlled by voltage) to adjust RF tuning. It is possible a bad varactor could cause low sensitivity at the low end of the VHF band. The control voltage applied to a varactor is adjusted depending upon the frequency being received which would be a function of the firmware. What firmware version do you have in the scanner? The latest CPU (uP) firmware is v2.1 and the latest DSP firmware is v1.4. It wouldn't hurt to reload the CPU firmware even if it is the latest version. To determine the firmware versions in your scanner: Turn off the scanner. Turn on the scanner. At the welcome screen, press 3.
Does 146.85 use a PL tone? If so, set it to carrier squelch or search and see if you can hear it. Did you reset the global settings to factory default?
With no signal using carrier squelch, you should hear RF noise. If you have quieting, there is interference.With the scanner paused/held on he 2m freq, what do you hear with the squelch open?
The OP's last response was about a month ago. I'm still waiting to hear if there is quieting with no signal on 146.85. There could an image or intermod from a TV channel. TV channels are 6 MHz wide which could wipe out the entire 2 meter amateur band.
The OP's last response was about a month ago. I'm still waiting to hear if there is quieting with no signal on 146.85. There could an image or intermod from a TV channel. TV channels are 6 MHz wide which could wipe out the entire 2 meter amateur band.