SIGNAL REPORTS - How Are You Heard? How Do You Hear?

Knowing how others are hearing you is critical to amateur radio operations.   You get this information through a "signal report" - you can request one, ("Can I get a signal report?") or you may just be given one as part of a club/operation protocol. 

Signal reports follow the RST format:

• Readability
• Strength
• Tone (for CW or morse code only, we do not use morse code so it will not be covered here)

Readability is given on a 1 - 5 scale as follows: 

1 - Unreadable

2 - Barely readable, occasional words distinguishable 

3 - Readable with considerable difficulty

4 - Readable with practically no difficulty 

5 - Perfectly readable 

Strength is given on a 1-9 scale as follows: 

1  - Faint signals, barely perceptible

2 - Very weak signals

3 - Weak signals

4 - Fair signals

5 - Fairly good signals 

6 - Good signals 

7 - Moderately strong signals 

8 - Strong signals

9 - Extremely strong signals 

An exchange regarding a signal report can go as follows: 

"Can I get a signal report?"

"Roger, I have you at 5, 9" meaning "perfectly readable and extremely strong signals". 

Or "You're coming in at about a 4, 6" meaning "Readable with practically no difficulty, good signals".

On HF the "S" (signal strength) portion of the report is tied to your S-meter. 

The S-meter is an instrument present on the majority of radio receivers that measures the strength of the signal that is being received, and uses unit of measurement called the S-point.

S-points go from S1 to S9 and each S-point is defined as a 6 dB change in signal strength. This means that each time the voltage is halved (–6 dB) the signal strength decreases by one point. S9 is already a very strong signal, but to describe larger signals, steps of 10 dB are used instead of 6 dB, noted "S9+20" meaning 20 dB above S9.

If they are at 20 over you would still report their signal as a "9", so perfectly readable with a +30  signal would be like "You're coming through at 5 9" ("five nine) or "I have you at a 5 9"

Here's a breakdown for the technical minded  people: 

S-points for frequencies below 30 MHz:

Signal strength	Relative intensity	Received voltage		Received power (Zc = 50 Ω)
S1	–48 dB	0.20 μV	–14 dBμV	790 aW	–121 dBm
S2	–42 dB	0.40 μV	–8 dBμV	3.2 fW	–115 dBm
S3	–36 dB	0.79 μV	–2 dBμV	13 fW	–109 dBm
S4	–30 dB	1.6 μV	4 dBμV	50 fW	–103 dBm
S5	–24 dB	3.2 μV	10 dBμV	200 fW	–97 dBm
S6	–18 dB	6.3 μV	16 dBμV	790 fW	–91 dBm
S7	–12 dB	13 μV	22 dBμV	3.2 pW	–85 dBm
S8	–6 dB	25 μV	28 dBμV	13 pW	–79 dBm
S9	0 dB	50 μV	34 dBμV	50 pW	–73 dBm
S9+10	10 dB	160 μV	44 dBμV	500 pW	–63 dBm
S9+20	20 dB	500 μV	54 dBμV	5.0 nW	–53 dBm
S9+30	30 dB	1.6 mV	64 dBμV	50 nW	–43 dBm
S9+40	40 dB	5.0 mV	74 dBμV	500 nW	–33 dBm
S9+50	50 dB	16 mV	84 dBμV	5.0 μW	–23 dBm
S9+60	60 dB	50 mV	94 dBμV	50 μW	–13 dBm

You may hear people refer to you being "just above the noise threshold."  There is always noise on HF that has to be sorted through, so in order to be heard, your signal has to be stronger than the ambient noise of the atmosphere/whatever else the other radio is picking up.  

In this picture, 1 is the noise threshold or the "weeds" as some people call it, 2 is the signal strength on the S-meter at about 6.2 - this is a noisy day and a noisy band, so in order to communicate you'll have to be putting out a really strong signal and they will have to have a good receiver/antenna and filter.

In this picture, 1 is the noise threshold, or noise "floor" (a quiet day), 2 is the signal from the station, and 3 is that it is coming in at "20 over" (This is 670AM from Boise but this was done to show you what we are looking at).  

For FM or VHF reports  are given in terms of "quieting."  "Full quieting" means there is no other noise coming in with your voice, you sound like you're speaking directly into the radio with no static or any distortion. 

The S-meters on VHF radios are not as accurate across all equipment as they are on the HF equipment, so giving a meter reading is ultimately not very informative.  

This is the S-meter on one of the Baofengs - not a whole lot of information other than for the user to look at the meter and see whether or not they are coming through full strength or a partial signal.  

You may hear people refer to having "a bit of sizzle" or "some bacon" on your signal (slang) referring to having some static. 

Signal reports typically aren't given or asked for over repeaters, if you can hit the repeater, others are hearing you, and you will know you are hitting the repeater if you hear the "ker chunk" after you release the mic, with repeaters, you're either getting in or you're not. 

When communicating with others, it is useful to let them know how they are coming through, as well as understand how you are coming through to them.  Remember, propagation can be fickle, you can have different propagation over different areas for different reasons (terrain, electrical grid, interference).