The RF gain is useful when you are in close to whoever you are communicating with (turn it down to reduce distortion).

It is compact & has great features like: Automatic Noise Limiter (ANL) cuts out alternator & engine noise, Public Address hookup (PA) allows you to hook up a speaker and yell at your buddies or the bad driver in front of you, and a RF Gain knob

This model forgoes an RF gain knob, which is essential for tuning down to the noise floor for distant stations.

It has nice adjustments in the RF Gain

I reviewed many radios and found this one to stand out in the small cb radio group because of RF gain and PA switch

The price does seem to fluctuate some, but most of the time it is only $10 more than the 510 but offers a public address function and more importantly adjustable receive (RF) gain

The RF Gain being one of the better features because you can turn it up to pull in weaker more distant signals and then adjust the squelch knob to block out the "static noise"

This unit has an RF gain which really helps dial in a signal from afar

The only problem was getting use to the squelch and RF Gain

Works easily and the RF gain is a nice feature

Works great!- RF gain control

The RF gain in particular is a bit rare in a radio like this.

THE FIRST NOB IS RF POWER, THE SECOND RF GAIN, AND THE LAST IS YOUR FINE TOON SQUELCH

Both radios are the same sizeand also have an outlet for an external speaker but the 520 has an RF gain adjustment, PA switch, and Channel 9 switch

For a basic radio, it has good features, i.e. S/RF meter, switchable ANL, RF Gain, and PA.

It feels like they put it together as cheaply as they could

I have an external speaker that I'm going to mount and hook up as it's sometimes hard to hear the unit inside the console.

Everything seems to work as it should.

Radio works as it should