Nope. It's called a random wire antenna and they are all over the internet. I use a full wave horizontal loop, another kind of wire antenna. If you can't figure out how to attach bare copper wire to your whip antenna with a paper clip or an alligator clip then try using scotch tape.
Don't let some smartass tell you that you need a 9 to 1 unun, a balun, a tuner or a ground system to make the random wire antenna work. All you need is wire and some way to get bare metal contact between the whip antenna and the antenna wire.
Add a plastic wind-up reel to a random wire and you get this.
Don't overthink the random wire antenna when using it as a receive-only antenna. Hams are going to tell you that you must use a balun, an unun, coaxial cable and cut the wire length to match the wavelength, use an antenna tuner, etc. but all of this is mostly nonsense when it comes making a receiving antenna for shortwave reception. Transmitting on shortwave is another matter.
I really feel sorry for noobs who come into this sub sometimes. You have all of these hams coming in here trying to prove how smart they are dumping a ton of information on them when all they really need is a reel-up antenna or a basic home made random wire. Sure there are some improvements that can be made to a basic random wire but stick with the basics, first.
Nobody here has mentioned that some portable radios work much better with external antennas than others. Most portable shortwave radios run the risk of overloading with much more than 23 ft. of wire. That's because they aren't using portable shortwave radios.
Would this be a good antenna? I know you said 15ft max length and this one is 23ft but that seems to be a standard size? I can't find any that are 15ft long.
Kaito T-1 Radio Antenna https://www.amazon.com/dp/B00066Z9XG/ref=cm_sw_r_apan_glt_fabc_E55DTH4FN6F35G1DZWCP
Doesn't it have a external antenna plug? Many of the cheaper shortwave wind up long wire antennas have a clip adapter to clip to the end of the whip, like this.
The user's manual will tell you how to use the radio. https://www.manualpdf.us/eton/elite-executive/manual
First antenna: Buy a reel-up random wire antenna, plug it into the radio and use it outdoors. https://www.amazon.com/Kaito-T-1-Radio-Antenna/dp/B00066Z9XG/
Better first antenna: Buy a 3.5 mm mono plug and solder it to 25 to a few hundred feet of stranded insulated 22 - 16 AWG hookup wire.
Here's a few things to get you started in this wonderful, if slightly ephemeral hobby:
short-wave.info - this is a fantastic resource to have pulled up on your phone or tablet while you listen, so as you scan the airwaves, when you find something, you can see what is broadcasting on that frequency.
Regardless of where you are, that telescopic antenna is only going to bring in so much. Start looking into external antennas, but the cheapest "upgrade" you can do is set up a nice long wire. I use this one since it winds up when not in use, and comes with a clip to just use it as an extension of the telescopic antenna, if you don't have an external ant jack on the radio. Cheap, effective and portable checks a lot of boxes for me since I live in an urban environment that is RF noisy.
You won't likely hear any numbers stations these days, but you can get a taste of shortwave during the Cold War era with this audio archive.
Get a nice world map that you don't mind writing on and a notebook. Or, if you're not old-fashioned like me, there's likely some nice map software out there that lets you take notes. In either case, take notes! Part of the fun of SWLing (short-wave listening) is signal hunting, looking for patterns or broadcasts that aren't necessarily listed (pirate radio!), tracking down beacons, etc.
Hard to tell from the very limited info in that listing, but probably not - the radio's connection is meant more for something like this Kaito T-1 Radio Antenna.
Note that that one (and most others you'll find) have a 3.5mm plug, not a 2.5mm - there's not really any standard for that type of antenna, and in more recent times they've settled on using 3.5mm. You'll need a mono 3.5mm socket -> 2.5mm plug adaptor to use it.
But really, they're nothing more than a length of wire up to about 10m/30' connected to the tip connection of the plug. Easy enough to make yourself with a 2.5mm mono plug and a length scrap speaker wire. Or, even easier, something like this and a length of wire.
-You should be able to find many shortwave broadcast and other station in Arizona. Living in a suburb and especially an urban area will pollute the shortwave bands with man-made noise (RFI).
-You can spend any amount you want for a radio: less than $20 and up. The better the radio the more it costs. I'd go for something under $100 for a good beginner's shortwave portable. I go with something that has SSB capability, an external antenna jack, variable IF bandwidth selection and a digital tuning display. Some good choices are Tecsun PL-330 from Anon-co and the XHDATA D-808 or Sihaudon D-808 from Radiowow. Get an inexpensive reel-up antenna to begin with.
-Giant antenna? What is a giant antenna? Some radios operate better with larger wire antennas than others and these radios will cost over $100. Wire antennas are fairly cheap to build.
-Some of my favorite stations I can pick up in California that you should receive in Arizona: BBC, RNZ Pacific (New Zealand), CRI (China), VOK (North Korea) RHC (Cuba). These are all English language but there are many others in other languages and many have excellent music. Also: there are a dozen shortwave broadcasters operating from North America. Use https://short-wave.info/ to find shortwave broadcasters. Read the instructions and set the ball on your location.
Even these are better than a telescopic whip for shortwave. You may have to try different directions/mounting locations to minimize RFI.
The Tecsun PL-380 does not have an external antenna jack. The PL-380ET does. The 380ET can handle a 23' antenna without overloading at the antenna jack. Longer than that is iffy. With the PL-380 you could probably clip one of these onto the whip for better shortwave reception. These are approx. 23' long. Use it indoors, outdoors, on the balcony, etc.
https://www.amazon.com/Kaito-T-1-Radio-antenna/dp/B00066Z9XG