For those who want to work all HF bands,
but still love Coax
I'm an old-timer. When I started in this ham hobby almost everyone used "doublets" (a half-wave dipole fed with open wire feeders). Life was simple. We hooked the feeders to a link in the coil of the output circuit and adjusted the loading by pushing the link in or out. Then a lot of coax was left over from WW-II and a lot of the surplus gear used 52 ohm input. Soon the commercial manufactures followed that trend. Now, every transceiver needs to see 50 ohms or it shuts down.
But that poses a problem doesn't it? Do you put up a trap antenna? Do you have multiple dipoles? Do you have to switch from band to band? You can avoid all that and still have all band versatility and have a happy radio, too. Try an extended "Zepp." That's any piece of wire longer than a half wave on the lowest band you intend to work. Or a full-wave loop which is even better. Those antennas like to be fed with the now convenient "window line" which is about 450 ohms. You can use a balanced tuner to match them to your radio - or, you can do as most guys do - put a balun in the feed line that transforms that 450 ohms to 50 ohms and feed coax to your transceiver.
You can wrap up a balun yourself for this job. It's really not hard to do. But if you don't have the time or don't want the trouble, DX Engineering will sell you s super matching balun in an nice aluminum box for nearly $200 bux. I have one that I used (inside the shack) when I was experimenting with simple breadboard antenna tuners. It's available on eBay for $95 and it's good as new. It looks like this:
You can read all about it by clicking