I need an antenna for RCA RP7664A portable radio. What kind should I look for?

A web search for your model turned up a blank. You aren't kidding about having it for years. I'll give you some generic information about AM radio reception and hope you find something useful.

Generally, AM reception is through a wire coil wrapped around a ferrite (very fast magnetic material) rod. Received signal strength is dependent on the angle between the rod and the radio station's transmitter antenna, so rotating it in a horizontal direction (around an imaginary vertical line through the center of the receiver) is often helpful. The angle of the best direction can be affected by nearby equipment (metal appliances, ductwork, computers, etc.)

Many non-portable audio receivers and a few boom box types have both an AM and and FM antenna terminal on the back. The FM antenna is very much like a TV antenna (you can use a TV antenna) and is generally required to get FM reception except in units with a telescoping antenna mounted to the case. The AM antenna is used to augment the coil signal, and is generally needed only if you are trying to pick up a weak signal. Attaching a wire to the AM terminal may help (make sure you have a good electrical connection between the terminal and the metal of the wire). This wire will also have an optimal angle for best reception. Try arranging it vertically; many AM radio stations transmit vertically polarized signals for the benefit of car radio antennas.The longer the wire is, the better, but it doesn't have to be very large. The physical limit is about 110 yards, the practical limit is how much you can stand to have stretched out behind the stereo. (A thin wire going up the wall to the hook behind a picture will probably not attract much attention.)

Portable radios often use a single telescoping antenna for both AM and FM along with the internal coil previously described. If you have this, experiment with antenna position and radio location. I have been told that some early model LED light bulbs may interfere with AM radio reception, especially if they are within a few feet of the radio.

eBay would be a great source for a new radio antenna. Go to eBay search and type in telescoping radio antenna. Choose Consumer Electronics as the category, and click Search. Choose the filter Lowest Price + Shipping First.

https://www.ebay.com/sch/i.html?LH_PrefLoc=1&_sop=15&_armrs=1&_dmd=1&LH_BIN=1&_ipg=100&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=telescoping+radio+antenna&_sacat=293

it is not the length of the aerial that matters but how it is wound there are books that explain the function of aerials and the relationship between windings and wave length or cycle so by studying the books and having a fibreglass fishing rod you can in effect may your own aerial to what ever length you like
next thing you can do is join a club for radio operators ( ham or otherwise) and you will be in an organization that will help you to get the best from your radio

Many boombox antennas are attached by a small screw through the pivot point. This is usually a #1 Phillips screw. Some do not have a swiveling antenna; for these you have to remove the back of the case to get at the attachment screw. Keep the screw; it's guaranteed to fit when you attach the new antenna.

The hard part is finding a replacement. If you have the pivoting/swiveling antenna, the Radio Shack 28" Replacement Telescoping Antenna 270-1405 ($5.99 online) will probably work. You might even be able to use it for a non-pivoting antenna that telescopes into the inside of the case.

If there is no coaxial cable connector on the radio, you simply cannot as a practical matter.

Antennas can be easy to find, but size may be not so easy

Ebay is your best bet for a low cost

However if you are not to bothered a simple thin piece of wire cello taped on to what is left should work just as well, recommend about 2 m of wire any thin wire will do as there is no current in the connection

If you do go down the route of replacing the antenna and have the original connector still sticking out where the screw goes threw your fine - or if its gone complete you should fine a small screw either at the base or the side casing, this should release the connection to the unit, however if not you will need to open it up

antenna cost about 4 - 7 quid depending on size, but as before if your happy to use a thin wire it should work just as well, or salvage a similar size one off a old radio etc... there will not be any sony parts for this its just a telescopic antenna used on many items

hope this helps a little

hello. you can order by phone 1-800-414-8655
Mon-Fri: 8am-5pm (Pacific Time)

Joe

if this is a portable tv; your state might have gone digital programming which you can only receive canada stations only. but see if you have an external antenna jack then you need the adapter to use with an antenna you can find it at radio shack.

I presume that you wish to connect an external antenna/aerial to a portable radio with no antenna connection. Wind several turns of your antenna wire around the telescopic antenna - should work ok!

It's possible to get the same antenna on ebay...

You can check here:
http://item.express.ebay.com/Consumer-Electronics_MP3-Players-Portable-Audio_Boomboxes_Boombox-Radio-Replacement-Antenna-12-Inches-Boom-Box_W0QQitemZ120194279381QQihZ002QQptdnZBoomboxesQQddnZConsumerQ20ElectronicsQQadnZMP3Q20PlayersQ20Q26Q20PortableQ20AudioQQptdiZ493QQddiZ945QQadiZ500QQcmdZExpressItem

or here

http://item.express.ebay.com/Consumer-Electronics_MP3-Players-Portable-Audio_Boomboxes_Boombox-Radio-Replacement-Antenna-12-Inch-Sony-RCA-Coby_W0QQitemZ120194280040QQihZ002QQptdnZBoomboxesQQddnZConsumerQ20ElectronicsQQadnZMP3Q20PlayersQ20Q26Q20PortableQ20AudioQQptdiZ493QQddiZ945QQadiZ500QQcmdZExpressItem