QSA and QRK radio signal reports

QSA system for radiotelegraphy[edit | edit source]

One of the earliest signal reporting formats is a part of the Q code used for commercial radiotelegraph communication, and later adopted by other radio services, especially amateur radio. The format was mandated by the Madrid Convention (Appendix 10, General Regulations) prior to 1936, and specified the following reporting format, as found in the 1936 edition of the ARRL's The Radio Amateur's Handbook and Radiotelegraph & Radiotelephone Codes, Prowords and Abbreviations.

Request from first station	Response from receiving station	Meaning
QRK (replaced earlier QJS)	QSA1	Hardly perceptible, unreadable
	QSA2	Weak, readable now and then
	QSA3	Fairly good, readable but with difficulty
	QSA4	Good, readable
	QSA5	Very good, perfectly readable

The book goes on to note that "Some of the definitions, however, appear to confuse audibility or signal strength with readability, which may be impaired even when signals are strong, by atmospherics, interference, a noisy receiver, etc.", and that because of this Amateurs supplemented the QSA system reports with a readability scale, called the R-System, which used a scale of 1 to 9. The book describes the QSA- and R-systems immediately after describing the R-S-T system, and notes that the R-S-T report format, because it is three digits long, cannot be confused with either of the earlier systems. The book does not clarify the method for requesting an R-S-T report instead of a QSA report. The report example given uses military call signs and the obsolete Q Code of QJS for readability instead of the current QRK:

Station	Transmission
MB6	3MY V MB6 QJS 3 K
3MY	MB6 V 3MY INT QJS K
MB6	3MY V MB6 QJS 4 AR
MB6	S7P V MB6 INT QJS INT QSA K
S7P	MB6 V S7P QJS 3 QSA 3 AR

The modern equivalent of that manual is ACP131(F), which includes these entries:

Signal	Question	Answer, Advice, or Order
QRK	What is the intelligibility of my signals (or those of...)?	The intelligibility of your signals (or those of...) is... bad poor fair good excellent
QSA	What is the strength of my signals (or those of...)?	The strength of your signals (or those of...) is... scarcely perceptible weak fairly good good very good