w6csn’s outdoor amateur radio

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Watch Your Tone

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w6csn

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In this modern era of radio technology, where even analog radio is largely digital, we amateurs are accustomed to perfect signal quality all the time.

Nevermind the perfunctory 599s that are handed out during contests, for activities like Parks On The Air and Summits On The Air I believe most of us like to send and receive an honest RST report.

R-S-T from the 1938 edition of the ARRL Handbook

Although subjective, readability (R) and signal strength (S) are pretty well understood quantities. But what about tone, the T in R-S-T ? When was the last time you sent or received a tone value other than “9” (the highest value) ?

Last evening, at the end of one of my frequent activations of the Presidio of San Francisco (K-7889), I struggled to pull a barely readable and very weak signal out of the noise. For what it’s worth, the natural noise floor was very low, with the geomagnetic field listed as “Inactive” on qrz.com.

One of these stations had a distorted signal 😦

What made the signal particularly difficult was that it sounded quite distorted. The problem I faced was how to tell the OM that it sounded like his signal had been through a blender. The numbers in the Tone scale go from 1 to 9 but I did not have any understanding of the specific defects encoded by the scale. I needed to send a report, and quick, so I dashed out a “225” followed by “DISTORTED.” But I was unhappy that I needed to send an extra, unexpected word to explain the reason for the “5” tone.

Tone

1–Sixty cycle a.c or less, very rough and broad.
2–Very rough a.c., very harsh and broad.
3–Rough a.c. tone, rectified but not filtered.
4–Rough note, some trace of filtering.
5–Filtered rectified a.c. but strongly ripple-modulated.
6–Filtered tone, definite trace of ripple modulation.
7–Near pure tone, trace of ripple modulation.
8–Near perfect tone, slight trace of modulation.
9–Perfect tone, no trace of ripple or modulation of any kind.

http://arrl.org/quick-reference-operating-aids

When I got home I resolved to refresh my knowledge on the R-S-T system so that I could have it at my disposal while operating and on the rare occasion when a tone value other than 9 is warranted.

May your signals always be strong and pure.

73 de W6CSN

3 responses to “Watch Your Tone”

  1. dolphus Avatar
    dolphus

    Early this year, I heard a signal that was certainly musical, but it sounded like a bird chirping. I contacted the operator, and he had a really interesting reason. I don’t think he’d mind if I copied it here.

    “Thanks for the report! I’m using a Heathkit VF-1 VFO that’s probably early 1960s vintage. They’re notorious for drifting and other issues but I worked this one over to make it as stable as possible. However, when you ‘key’ a VFO like this, the sudden on and off operations make the frequency shift slightly, causing chirp.

    Chirp was pretty common when I was starting out and was considered undesirable, and still should be. However, for nostalgic reasons, I and a lot of old timers like hearing it from time to time. The beautifully pure signals we hear these days get monotonous. Ha!

    If I ran the VFO continuously while transmitting I might eliminate or reduce the chirp. But I’d have to flip another switch going between transmit and receive since it would interfere with my reception.

    I probably would have heard you if you’d called. My receiver isn’t super selective. Plus, in the old days, it was considered good practice to tune up and down after calling CQ in case someone using crystal control answered.

    73 & HNY,

    Nick, WA5BDU”

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    1. w6csn Avatar
      w6csn

      A little chirp is not bad especially if the CW obviously being sent with a straight key.

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  2. dolphus Avatar
    dolphus

    I agree. I thought it was pretty awesome. I’m with Brad, everything else gets a little monotonous 🙂

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