SINPO & SIO CODE
SINPO is an acronym for Signal, Interference, Noise, Propagation, and Overall. It is a universally adopted reporting code use to describe the quality of broadcast and radiotelegraph transmissions. (Michael 2024)
It was developed by the Comite consultatif international pour la radio (CCIR) in 1951 for use in radiotelegraphy. The standard is contained in Recommendation ITU-R sm. 1135 SINPO and SINPFEMO codes. (Wikipedia 2024)
| r-rec-sm.1135-0-199510-i__pdf-e.pdf |
The SINPO code uses four (4) for 4 reception parameters to be rated and a logged and a final overall evaluation of the reception. Each letter of the SINPO code stands for a specific factor of the signal, and each factor is graded on a 1 to 5 scale. (Michael 2024)
A SUBJECTIVE REPORTING SYSTEM.
Although the above chart may appear concise, the SINPO code is very subjective. One SWL may rate a station as 33232 while another may rate it 44333.
SIO CODE.
The SIO code is based on the SINPO code, however it is in a simpler form.
S - SIGNAL STRENGTH |
I - INTERFERENCE |
O - OVERALL |
5 - excellent |
5 - no interference |
5 - excellent |
4 - good |
4 - nil or very slight |
4 - good |
3 - fair |
3 - moderate |
3 - fair |
2 - poor |
2 - heavy |
2 - poor |
1 - useless |
1 - extreme |
1 - unusable |
VIDEOS.
SINPO code explained.
A closer Look at SINPO.
References.
- 1. Rob Wagner VK3BVW, You Tube, <www.youtube.com/watch?v=30oKuvGEU0E&t=0s>
- 2. Michael (2024). Unlocking Signal Quality: Understanding the SINPO Code in Shortwave Listening – Tecsun Radios Australia. [online] Tecsunradios.com.au. Available at: https://www.tecsunradios.com.au/store/unlocking-signal-quality-understanding-the-sinpo-code-in-shortwave-listening/?srsltid=AfmBOoqdxgqo8BJ6F2jAkheodKHtaPZHY60Z1dJ27EU3v5NaRetCkBTZ [Accessed 1 Jul. 2025].
- Wikipedia. (2020). Signal strength and readability report. [online] Available at: https://en.wikipedia.org/wiki/Signal_strength_and_readability_report.