This video demonstrates a clean, repeatable method for comparing antennas using WSPR via fixed time slots, fixed power, and real data – not opinions. It is not about comparison done by ear, S-meters, or quick swaps – which can lead to the wrong conclusion.
What this video covers:
– A practical A/B antenna testing method using WSPR
– Why ABABAB testing beats day-to-day comparisons
– How to log RX and TX properly
– How I analysed the data using ChatGPT as a coding assistant
– Why time of day matters more than people think
What this video is NOT
– Not a propagation report
– Not a claim that one antenna is "best"
– Not sponsored or influenced
Links
https://www.wsprnet.org/drupal/ – WSPRnet database
https://wspr.hb9vqq.ch/ HB9VQQ – Sanity-check site
https://mega.nz/folder/IjZgkQCL#RsEp13CDeK2JvWTMiOuMyw – Files
EXACT CHATGPT PROMPT USED:
Hello ChatGPT.
I have conducted a controlled A/B antenna comparison using WSPR only.
Both antennas were tested:
at the same station
on the same band
at the same power
within clearly defined time windows
Nothing else was changed.
I am about to send you three files:
1 The Timeslots Log in UTC (which antenna was in use and exactly what time)
2 The Receive Log in UTC (work out which antenna was in at any time via the Timeslots log)
3 The Transmit log downloaded from WSPRnet in UTC
The logs are accurate and in clear two-minute chunks – there is no need to be concerned about the times.
My timeslot log includes the antenna label for every 2-minute WSPR slot (including RX-only slots).
Your tasks:
TX analysis: Identify which antenna was in use for each transmit period. For each antenna, calculate:
– total number of reports
– number of unique reporters
– median SNR (not maximum)
– median distance
Group TX results into distance buckets:
– short haul (0–2000 km)
– medium haul (2000–4000 km)
– long haul ([greater than] 4000 km)
For each bucket, show report count and median SNR.
RX analysis: Using the RX log, separate decodes by antenna and time window.
For each antenna, calculate:
– total decode count
– median RX SNR
– median distance (if available)
Output requirements:
Present results in clear tables.
Do not declare a single winner.
Explain what each antenna appears to be better suited for – based on the data.
Focus on differences in behaviour, coverage, and application rather than preference or opinion.
Base conclusions strictly on the data provided, not on predicted behaviour
Explain how you calculated the results
I will send the files in the next message. Please confirm you are comfortable with my prompt.