I've got a high opinion of this radio. It's the last of the 'decent-sized portables' left on the market. As of 2013. And with the little LED tuning indicator, which will either pulse or changes color in accordance with signal strength, it reminds me of the 'traditional style' SWL'íng radio like I started with back in the 1970's.
How does it perform, you want to know? Well, once you connect a wire antenna, either directly to the extendable whip or into external antenna jack, this radio becomes a true shortwave receiving POWERHOUSE. And sounds good too. Otherwise its deaf on the extendable whip. So be sure to add plenty of wire. Don't be shy, the radio can handle it.
It does great on SSB, that's what I mainly use it for. Don't let any crackpot tell you otherwise. Anyway, yes, I really like this radio.
This unassuming radio with SSB capability has been on the market for over 13 years. Longer than most. You don't hear much about it, but obviously it continues to sell well enough for continuing production. Now, whether you praise it or condemn the ATS-505P depends on the reason you buy radios: (a.) you enjoy radios and their different personalities, or (b.) you like to rate the technical apsects of radios only to never use them again. If you're (a.) then I think you'll find the ATS-505P more than satisfactory. I do.
You *must* use a decent length of wire for antenna on shortwave -- the radio is totally deaf on its telescoping whip. But the payoff is huge: when you do the amount of signals that come pouring in, across the entire shortwave spectrum, SSB included, will make your heart light up with joy. You'll want to throw away all your other shortwave radios. Not to mention the ATS-505P has a good, powerful audio stage. It really pushes the sound.
True enough, there's no 'serious' selectivity, no I.F. filters to choose when using SSB, but it still doesn't detract from the experience -- when using a good wire external antenna. The sideband signals sound good, they come in strong, the BFO is almost completely stable, there's no real reason to gripe about a technical aspect.
The radio is decent-sized, has a comfortable tuning knob (which now, on the newer version, doesn't mute or "chuff") and the display has very large, easy to see characters. In summary the ATS-505P is a great buy for the price. If you want save $40 then go to Radio Shack and get their branded model of the exact same radio, the 20-629. Its worth it. Unless you're total crank. Just be sure to connect a good length of wire to the radio for a shortwave antenna. You'll be glad you did.