Measuring Antenna Performance Using WSPR

Editor’s Note: This article originally appeared in the September/October 2025 edition of “The Canadian Amateur” magazine and is being republished here with permission from the author, Jim Leslie, VE6JF.

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How do you know your new antenna works if you don’t measure it against your old one?

I pondered that question when I added a new receiving antenna system. I wanted to know if it was better or worse than my existing one. This article describes how I did it using Weak Signal Propagation Reporter (WSPR).

I live in a city suburb and the gradual increase in local QRN (manmade noise) over the years finally reached unacceptable levels so I decided to add a dedicated low-noise receive system to complement my transmit antenna.

This was built around the DX Engineering NCC-2 Receive Antenna phasing unit and a matching pair of DX Engineering Receive Short Element Active Vertical Antennas (DXE-RSEAV-1).

My main interest is Weak Signal CW (Continuous Wave), which is the use of Morse code transmissions in conditions where signal strength is extremely low, often below the noise floor. My focus was on improving my Signal to Noise Ratio (SNR) particularly for 40 metres, which is my noisiest band. I also wanted to objectively measure the performance of the new system compared to my existing antenna.

To conduct this evaluation, I used a software suite called WSJT-X, developed by Joe Taylor, K1JT.

WSJT-X is widely used for weak-signal digital communication. It includes several modes designed for making reliable contacts under extreme conditions such as FT8, JT65 and WSPR. Each mode serves a
different purpose, but all are optimized for low power, low bandwidth transmissions that can be decoded even when signals are below the noise floor.

WSPR provides the ability to measure and evaluate receive (or transmit) performance. WSPR beacon stations around the world transmit 24 hours a day on most bands.

These stations can be received and the spots saved into an easily accessible global database. Combined with sophisticated but easy to use web tools, this provides the user with the ability to perform comprehensive analysis of station changes of any kind including new antennas, equipment, cabling or ground changes, or even antenna orientation.

This data is always available for retrieval at any later date and in the longer term provides the user with the ability to retrieve and compare changes to your station at any given time.

WSPR takes the guesswork out of antenna evaluation and with the new web tools to analyze and visualize results, measuring antenna performance is surprisingly very easy to do.

Test Setup for Antenna Comparison

Living on a small city lot, I have only had a single antenna for almost a decade. It is a carefully tuned Hustler 6BTV 6-Band HF Vertical Antenna with 68 radials, a high-quality DX Engineering current balun and good grounding. Combined with excellent low-loss UHF hardline, it has worked very well for me over the years.

Short of a tower and beam, I am satisfied that it is the best I can do in the limited space I have available.

To complement this, I installed a pair of DX Engineering RSEAV active receive-only vertical antennas along with an NCC-2 phasing unit which provides phasing and noise cancelling using two antennas.

The NCC-2 output was then connected to the RX antenna port of my TS-890. Next, I methodically started comparing relative receive performance between them and the 6BTV using WSPR to obtain
receive results of each.

When comparing two antennas, the most accuracy will result when signals are received from both antennas concurrently. This eliminates any short-term propagation changes skewing results. To do this, I configured my PC to run two instances of WSJT-X in WSPR mode as shown in Figure 1 and
Figure 2.

In one instance I connected it to my Kenwood TS-890 Transceiver and the new active verticals. In the other I connected it to an RSPdx-R2 SDR and the 6BTV.

Note: The SDRplay RSPdx-R2 is a single-tuner wideband full featured 14-bit SDR which covers the entire RF spectrum from 1 kHz to 2 GHz giving up to 10 MHz of spectrum visibility.

I then ran both instances of WSJT-X concurrently and collected WSPR data for extended periods, using the option to post my results to the WSPR database. Next, I used various web tools to do the heavy lifting to retrieve and analyze the wealth of information received.

I was able to investigate not only the number of stations received over a given period for each antenna, but also see the SNR of each, where they are located, direction, distance and so much more.

Gathering Data

Configuring two instances of WSJT-X each connected to its own antenna is done by creating two shortcuts to the application each with different targets (rig-name). For reporting purposes to the global WSPR database, it is necessary to add your call to one instance of WSJT-X and an alias to your call in the other instance.

For example, in my case, results were reported to the WSPR database as VE6JF on the receive verticals connected to my TS-890 (see Figure 1, above) and VE6JF/6 connected to my RSPdx-R2 SDR on the 6BTV (see Figure 2, above). I entered this on the “Settings”, “Reporting” tab in WSJT-X.

This naming convention lets me identify which data set belongs to which antenna. Don’t forget to enable reporting by checking the option “Upload Spots” on the main page in each instance. Following this, the WSPR spots you receive will then be uploaded to the WSPR database.

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