Diamond NR770HBNMO vs. Comet M-24M

The Diamond Antenna NR770HBNMO paired with their K515S insulated luggage rack mount provides measurable and observable upgrade for my 2015 Subaru Forester 2m/440 mobile.

Slim Jim vs. Traditional J-pole Antenna

Measured gain of SlimJIM and J-Pole

Real measurements of a Slim Jim antenna and traditional j-pole antenna reveal the truth about their respective gain and pattern.

Have your J-Pole and ground it too

1.06 GHz Test J-Pole Antenna

Tame the predictable mast currents found in any j-pole antenna grounding conductive mast using a simple stub. Shown is empirical evidence why this is a problem and a very simple solution all future grounded j-pole antennas should incorporate.

Hoverman TV Antenna Measurements

Hoverman VHF Elevation Measured Antenna Pattern

Doyt Hoverman’s 1960s TV antenna design placed over a simple reflector screen provides impressive performance for today’s UHF and VHF-HI television bands.

Build this Vertical Portable HF Antenna

This antenna fits into a baseball bag except for the tripod.

The Asymmetrical Hatted Vertical Dipole (AHVD) prototype is an easy to build, portable alternative to other freestanding vertical HF antennas such as the Buddipole.

40m Mastless NVIS Antenna

Folded 40m NVIS Dipole Concept

Yet another 40m Cloud Burner design featuring a folded dipole driven element plus one reflector wire to facilitate 40m NVIS contacts without need of a tall mast. The design uses electric fence posts for support and needs no balun.

Superbowl HDTV Antenna

Build the venerable Hoverman TV antenna and watch digital broadcast high definition HDTV television this weekend. This version of a HDTV antenna uses amateur radio antenna building techniques to make a lightweight structure.

SWR of Several Mobile Antennas

I had occasion to test four popular amateur radio mobile antennas. Here are the results of SWR and Return Loss of a Diamond SG7900ANMO, Larsen NMO 2/70, Cushcraft CS-270M and Laird QW144.

Improving the Super-J

Full view of various Collinear J-Poles

The traditional collinear J-Pole, aka Super-J, improves the basic J-Pole. Are further improvements possible? By replacing the phasing stub with a simple coil, the answer is yes. The result is the Collinear J-Pole.

EFHW LNR Precision EF-10/20/40MKII Test Data

SWR Measurements of LNR Precision EF-10/20/40 End Fed Antenna

Basic tests of the LNR Precision EF-10/20/40 multi-band portable HF EFHW antenna including S11, SWR and a bandwidth check of the match box.

Antenna Measurements on Taurus 2m Whip

Return Loss and SWR measurements of a permanent 2m whip installation mid-roof of a Ford Taurus. The effect of doors is shown.

Lab Tests: SMA, BNC, TNC and N Connectors

Lab tests show post WW2 connector designs perform exceptionally well up to 500 MHz. The SMA, BNC, TNC and N connectors are great.

PL-259/SO-239 Return Loss and Attenuation Test

We pit the PL-259 (and SO-239) against more recent connectors. This is the list of contenders plus a description of the test setup.

Coax Velocity Factor in Baluns, Does it Matter? Part 1

Test results show coaxial cable velocity factor does not always enter into stub length calculations especially in the world of Baluns. Part 1 of 2.