160m is cool.

“Top band,” “the Gentleman’s Band,” “MF” or whatever you call it, 160 meters is a blast. And it’s surging in popularity, much thanks to Joe Taylor and his weak signal modes. You may have opinions on those modes counting as real radio or not, but your opinion doesn’t really matter. The fact is that more operators than ever are finding 160 and most of them are doing it from city lots!

The true beauty of 160 is that the playing field is pretty level; even the most extensive arrays are still very much compromise systems. Consider for a moment that a true 1/4-wave vertical made out of tower sections is only as effective as it’s radial network. Consider for an additional moment that your wire inverted-L over a more extensive radial field might just smoke that first example.

Nick, K1NZ runs an inverted-L with a single radial, no RX antenna nor amplifier, and works EU on demand with the new FT8 mode. At my current QTH, I’ve worked at least 100 countries with a simple half sloper and a 250′ beverage-on-ground (BOG), primarily on CW. Neither of us are particularly skilled with antenna modeling and both of us face space restrictions.

There’s a lot of information online for anyone looking to get on topband, and plenty of misinformation. Here’s what I’ve learned as it applies to this QTH only (your mileage may vary):

  • Verticals crush dipoles on 160. Crush is the strongest responsible word I can find to use.
  • Elevated radials are better. I found 6-8 played nice with inverted-L type antennas here over the years.
  • Buried radials are less efficient, so you’ll have to use more. The point of diminishing returns at my QTH was 30 evenly-spaced radials slightly buried or on the ground. This agrees with the consensus among various mailing list geniuses.
  • Use an amp. Absorption is very high on 160; the extra dB’s help.
  • Nobody really understands propagation this low, and the best openings may only last a few minutes — VOAcap and similar programs are critical for the serious operator.
  • Immediately at grayline (and ONLY then), my low dipoles outperform my beverages for RX and my verticals for TX. There is no good explanation for it, but ON4UN notes a similar phenomenon.
  • Beverages are cheap; build one if you have the real estate. If you don’t, you should try a BOG. If you don’t have space for that, try a Shared Apex Loop or a K9AY loop. There’s no excuse for being an alligator!
  • Learn CW. Try the JT weak signal modes. Do something new.

See you on topband!



Revolutionary 160m antenna at N1TA

I remember it vividly. I was standing on the edge of my toilet hanging a contest plaque, the porcelain was wet, I slipped, hit my head on the sink, and when I came to I had a revelation. A vision…a picture in my head. A picture of this! This is what makes 160m possible from a city lot: the DX capacitor! It’s taken me nearly twenty years and my entire fortune (EDITOR: $300) to realize the vision of that day. Gosh, how has it been that long?

Basic design of the DX capacitor

The capacitor is easily constructed and inserted at the feedpoint of your series-fed vertical. The smaller the vertical, the better it will work. I constructed my prototype for less than $50 with parts I had in my junk drawer and I’ve already worked 160 Meter DXCC…twice. In a single month. No listening antenna required.

The prototype in use

Fair warning: the 1.21 gigawatt power supply was very, very difficult; I recommend consulting an experienced local ham and/or astrophysicist (what difference is there?) to help you with the construction. World events and global politics may severely impact your ability to complete this element of the project, so be sure to check ahead of time.

These angry OM’s chased us home from AES!

I’ve been attempting to bring these to market, but there seems to be little interest from DX Engineering and MFJ. Luckily, Dr. E. Brown Enterprises, located in the new Twin Pines Mall next to the Hill Valley HRO, has agreed to construct and market the device to the amateur market. Please contact them directly with sales and design questions.

Dr. Brown works out of a van

The next topband season is just around the corner, so don’t wait. Get started on your own DX capacitor today and work the world before you’re outatime!