Here is some detailed information on the vintage CM Traveling Wave, Id thought Id share...from Television Antenna Handbook, by Jack Darr, 1959.

The top and bottom pics were taken in the foothills of North Carolina recently, of a Traveling Wave still in use! HatTip, markdd @ DigitalHome.ca Forum.

I think its sufficiently different to be a unique design, and not a yagi. It's not log periodic either, but perhaps a precursor to the log periodic.

Speaking to is this a yagi? Is this a log periodic?

First it's neither, though closely akin to both.

Yagi: The elements are dipole (folded dipole) in nature and the driven elements are in front of reflector. It has a central boom like a yagi. A lot of the similarity ends there.

Log: It has multiple driven elements like a log periodic. But beside using folded dipoles there is another major difference. Look how adjacent elements are phased. The are connected on the same side of the boom, where log antennas connect the next element to the other side of the boom.

The diagram 29 is priceless. Never seen it drawn out so well.
The fact that sweeping the elements puts the harmonic resonance in phase the point I mean in the diagram 29. This is also true of log antenna as far as swept element.

Log Periodic: A lot of the older log periodic TV antennas that don't have a corner reflector for the UHF part, make use of third harmonics of the TV bands. While the bands don't provide perfect third harmonics, they are close enough so a driven element on low band can be a reflector or directors on high band operating at a third harmonic. Also the same holds true between high band and UHF. As figure 29 points out, the elements need to be swept as that diagram notice the author shows the current on dipole type elements which a log periodic uses (not folded like a traveling wave).

This again proves, the best text on antennas came from the 1950 to 1980 era roughly. All stuff these days is how and which computer modeling program to use. The older text often puts it in simpler terms and very little has changed that wasn't known back then about antennas.

JER's CS design to me can be thought of as the marriage of two types of antennas.

1) The thick loop of vintage indoor UHF antennas of the other thread. Vintage Radion UHF Indoor Loop Antenna

2) The bowtie antenna more like a Channel Master 4149 Double Bow Tie


The loop is known to have more gain than a dipole. Any antenna that uses thicker elements is broader in band width.

Then take the CM4149 and fold the ends of each bowtie in a loop, so the thickest part is at the top.

The CM4149 or any bowtie (sister antenna the whisker like a DB2,4 or CM4221, 4228) has more band width than a plain dipole due to the tapered elements. Hams have done this for decades. Instead of a single wire dipole, they would attache two wires to each side of the dipole (huge whisker). The placed an insulator at the ends of the dipole to separate the two wire by a fixed distance at their ends. They found on bands like 40 meters with it's high percentage band width they could cover more of the band with a low standing wave.

If someone had a LOT of room and big big tower, it would be interesting to build a 2 element 40 meter loop antenna antenna with each element two loops, maybe three, with them joining at the bottom feed point and separated by a spacer at the top. Each element would look something like a huge CS1 but with at least a reflector built the same way.

BTW, Jack Darr's book is from 1959, I think the Traveling Wave was introduced by Channel Master in 1956 or 1957, about the fanciest VHF design at the time, dare I say it, innovative.

Here is some more information on the Traveling Wave Antenna from Mississippi State University... (also Rhombic, Yagi-Uda, Log Periodic). Heavy on the math, but also some clear descriptions.

There is also this book...

Traveling Wave Antennas
Carleton H. Walter
Hardcover, 448 pages, 1965


Introduction to Traveling Wave Antennas (pdf) by Fabrizio Frezza

I spotted a Channel Master 5 element Traveling Wave mounted on an small old house, on Highway 61, while traveling across state via the backroads, South Carolina on the way back from fly fishing on the Chatooga River. I may try to recover it, as the house doesnt look occupied, though it was reasonably upkept, I might can track down the owner and do a swap for a Kosmic SuperQuad. The antenna is is fair condition though its feedlines are shot. For some reason the antenna is mounted upside down....pretty common for antennas.