Hi I haven't done shortwave in a couple years and poped my current radio by hooking it up with an alligator clip I plan on pirate monitoring and am leaning towards a rs 505 clone considering there the cheapest iv seen some on close out as low as 45$ if I can find one if not want a pl 660 my question is if I get a long wire balun can I hook a long wire up safely or would splicing a mone patch wire with the negative lead grounded well please help and keep in mind I don't have a lot of money
The Radio Shack radio is a good radio for the money.
You don't need a balun -- you want to use one, go ahead, but I have never used one, and am not sure how necessary one would be with a shorter wire.
And I wouldn't use a very long wire to start with. The radio you mention here (Radio Shack 20-629, the "PLL Synthesized World Receiver", an updated ATS-505 with a different audio chips in it) is pretty sensitive.
I use mine with a 25 ft. indoor wire and get good results. I've heard a couple pirates on it. But I mostly hear the international broadcasters and some Asian stations, SE Asian stations, and South American broadcasters, as well as some hams. When propagation's good I hear Kuwait OK.
If you try a very long wire, it could overload the radio.
Just rig up a 20-30 foot indoor wire, solder the end of it to the tip of a 1/8 inch mono jack, and plug it in to the Radio Shack radio's external antenna jack. If you want to add a ground, you could add it to the 'shield' side of the mono plug, but if it's a short wire antenna a ground won't really do much.
With any outdoor antenna you'd want some sort of ground available to ground the antenna when not in use. If you try a longer wire with a digital portable, you always have to be aware that they are so sensitive (designed to work with the whip and shorter wire antennas) that they can overload a bit, causing images of stations to appear about 1 mhz lower than they really are. This can be problematic at times, and sometimes it's just a minor nuisance and can be worked around by using the radio's "DX-Local" switch and setting it to "Local". A lot of this also would depend on how strong SW signals are in your area. Some areas of the US have stronger SW reception than others.
If you get the Tecsun, I don't know how an external antenna is connected to one of those.