When Would I Recommend a SteppIR UrbanBeam on an ALM-31 Tower?

I received the question that you see in the Title today (from Chris, KJ7I), and realized its a great Blog topic. Thank you Chris! Lets start with how the antenna works:       These are wonderful animated EZNec plots that are featured on Dan, AC6LA’s phenominal web site: https://www.ac6la.com/ The reason I searched for EZNec plots for the UrbanBeam is that I did not…

Why I Decided to Buy an UrbanBeam

Animated Model by Dan, AC6LA For quite a few years I have stayed away from SteppIR antennas. I actually had the 2 element yagi back in 2006, but started reading about problems with the Stepper motors or other associated hardware. I sold it and swore I’d only stick to aluminum because I could fix anything if it went wrong – and fix it very…

Multiband Antenna Switching

When I first started on this project I think my goal was to “magically” handle SWR on several bands and my area of focus was on using an UNUN or Current Choke to do so. They did do what they were supposed to – to a point, but there was no “magic” there. They did bring the match “close” to the range of the…

Urat and inverted l

I now have the antenna in this configuration (128 feet total length), and also have the u.RAT ready to be set into it’s waterproof box and wired up. The fancy schmancy u.RAT control console  Because I have a shorter antenna with the far end up off the ground, 160 tunes well, but 80M now tunes at a 3:1, so I will probably have to…

The u.RAT Rides Again!

The u.RAT will be put into service – now that I have switched to the Grounded Loop / Inverted U low band antenna On the left, the Spiderbeam aluminum mast used as a vertical – with Alumox between each joint, plus two hex head socket bolts and the clamps that came with the mast. On the right – 41′ of DX Engineering aluminum –…

Inverted U Matched on 160 and 80M WIth Low Pass (??) Circuit

This low pass (??) circuit lets me get on 160M CW and 75M SSB with very low SWR and no tweaking. I would need to tune when going down to the CW portion of 80M. The Variable Capacitor is a Palstar C600 and the Roller Inductor is a Palstar RI-28. I tried quite a few different L circuits (all of the 8 documented in…

High Pass T Circuit

High Pass “T” Coupler Circuit from http://www.w0qe.com/Papers/Antenna_Tuners.pdf Trying to get 4 bands 160 – 30M (and maybe even 20M as a bonus) is tricky with a 2 component L circuit, so I will follow Larry, W0QE’s lead and start with a High Pass “T” circuit – which gives great range at the sacrifice of a little loss. I plan on trying to find one position…

Low Band Grounded Loop

The ARRL told me that they do not plan on continuing to update this book with new revisions. If you don’t already have it – you really need to order yours now – because it is already a classic.  More than ever, the combination of Low Band Antenna Experimenting and Maker projects is the cats meow in Ham Radio. I don’t even care so…

Benefits of Son of Mod Bob

There are several things that will be big benefits from Son of Mod Bob: I will remove the center element which is way to close to my 40M vertical array. This will eliminate the distorted 40M pattern I will no longer turn on the Trane HVAC when I transmit at full power I get three antennas in one, a half square on 40, Inverted…

The Grounded Loop Antenna (Thanks Jan, OM2XW!)

The feed is a simple L-C circuit, left, and the antenna can be switched between being an Inverted U or Grounded Loop, right Jan, OM2XW, wrote and reminded me of an antenna that is in the ON4UN Lowband Book, and one I have never tried. AA7OK has a VERY nice write up with great references at his web site – http://litlisten.com/aok/ As I understand it –…