Independent NB/ANL operation on CB/10 Meter radios

[FredTx63]

I've never been a big fan of what the Automatic Noise Limiter (ANL) does to receive audio on most CB & 10 meter radios. To me, it seems like it just whacks a lot of high frequencies giving you the illusion of lower noise at the expense of fidelity. Unfortunately, the NB/ANL setup on most CB & 10 meter radios is configured where to have the NB on, you also have to have the ANL on. Has anyone ever modified a radio like so you can control NB independent of ANL or are they basically the same circuit on most radios? Example: Cobra 29 LTD Classic.

 

[sp5it]

Just use 2 switches instead of one with two sections.

 

[nomadradio]

The NB will be on when the switch controlling it is closed. The Noise Blanker is an active circuit that requires power. The switch simply removes the NB circuit's power to disable it.

The ANL is the exact opposite. The ANL switch will short across a diode on the radio's circuit board to turn the ANL off. Opening the switch to remove the short is what makes the ANL active. Totally the reverse of the Noise Blanker.

73