Sidetone Pitch

Discussion in 'Straight Keys - CW Enthusiasts' started by AA4OO, Sep 9, 2015.


Sidetone Pitch

  1. 800 Hz or higher

    6 vote(s)
  2. 700 Hz

    17 vote(s)
  3. 600 Hz

    23 vote(s)
  4. 500 Hz

    11 vote(s)
  5. 400 Hz

    4 vote(s)
  6. 300 Hz

    0 vote(s)
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  1. AA4OO

    AA4OO XML Subscriber QRZ Page

    I find that I've gravitated toward a sidetone pitch between 540-570Hz but a ham friend of mine recorded one of our QSOs and sent it to me and it was pitched somewhere around 750 Hz. Now he's been an avid QRP operator for many years and is expert at digging out weak signals.

    I'm curious what sidetone pitch you prefer and if there's a technical reason for your choice?
  2. KC9UDX

    KC9UDX Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    I mostly end up somewhere from 700-1200Hz. But, it's not always the same. And being that I'm not all that experienced, there's no particular reason that I'm aware of yet.

    I think the actual sending sidetone on my KW is around 1kHz. That may have something to do with it.
  3. K8JD

    K8JD Ham Member QRZ Page

    What is that Tone ?
    I read, a long time back, that in the lower audio freq range, CW tones are easier to discriminate, when closely spaced, slightly higher and lower frequency tones are heard together.
    That is , higher pitched CW note tones have to have a wider freuency spacing for your ear to separate them than lower pitched notes.

    I have tried listeninng to higher and lower groups of tones (using multiple output audio sine wave generators) and tend to agree that two closely separated tones are easier to discriminate in the lower range than in the upper tone range.

    I have reset my rigs that had the capability to change the filters, from 800 Hz or 1KHz, to the lower range. 400 to 5oo HZ seems the best for me.

    Also, I find my hearing is failing at the upper range and this was verified by an Ear Doctor that My GP referred me to.

    How do you know what the tone frequency actually is ?
    Check your workbench multimeters, some Digital multimeters have a frequency measuring range. I have had a few inexpensive meters , bought at Home Depot and bigger hardware stores that have the capability and can be clipped across ext speker wires to read audio freqs from 20 HZ to ultrasonic frequency.
    The Fluke meters (expensive) I used at work were also good freq meters to use on phone lines, CTCSS, DTMF, and other apps where you had to check a freq of tone signal.
    Last edited: Sep 10, 2015
  4. AA4OO

    AA4OO XML Subscriber QRZ Page

    I'm still new at this but as I understand it the CW you transmit is based on the frequency your transmitter is tuned to and isn't directly related to your sidetone.

    The only relationship of the tuning frequency to your sidetone pitch is for zero-beating the station you're calling.

    When you zero-beat a station (match the CW pitch you hear to your sidetone pitch) you are matching your sidetone pitch to an offset from the actual received CW frequency from the transmitting station. We do this so that we are transmitting back on their frequency. So your sidetone is just an audio offset to the tuned frequency.

    My question is more related to what pitch do people choose for a sidetone and why? I understand that their is mathematically more discrimination between low pitches in terms of percentage difference which would lead me to think we can zero-beat a station more easily with a lower pitched sidetone, but on the other hand, when digging out weak signals, a higher pitched sidetone may be easier to separate from the background noise, especially with a tight filter.

    For instance, I find myself moving my passband higher to remove lower pitched audio artifacts when I'm trying to copy a weak signal...

    I think I'm talking myself into using a higher pitched sidetone for weak signal copy and maybe a lower pitched sidetone for QRO ragchewing (not that I have a QRO radio) but when I'm listening to one I think I'll use a lower pitch to help me zero-beat them better.
  5. KC9UDX

    KC9UDX Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    That's correct. I think we're using the term 'sidetone' for the receive audio, which isn't really a sidetone the way I understand it. I could be wrong.

    Most of my radios don't even have a sidetone.
  6. AG6QR

    AG6QR Premium Subscriber QRZ Page

    When listening to a group of stations in a net, I used to use a low sidetone, 400Hz or so, for the reasons already given: it makes it easier to hear the difference between one station's frequency and another's. But then I found that, sometimes, there would be a station a couple hundred Hz down from most of the net, and his pitch would be so low as to be inaudible. When I put the sidetone up around 700Hz, that problem went away.

    For a QSO with an individual station, I'll keep the filtering narrow, and it doesn't matter too much what pitch I use. 500 to 550 Hz is nicely comfortable for my ears.
  7. M0LEP

    M0LEP Ham Member QRZ Page

    My best aural sensitivity is around 400-500Hz. I find it best to set my rig around 440Hz. I can listen to much quieter signals there.
  8. K7KBN

    K7KBN Ham Member QRZ Page

    I use my RIT control to whatever sounds "right" at the time. There is no "best" audio frequency for everybody, and if you can copy 15 WPM at 400 Hz you can copy 15 WPM at any other frequency you can hear. Band conditions and amount of interference dictate things much of the time.
  9. AG6QR

    AG6QR Premium Subscriber QRZ Page

    I think you're exactly right. Sidetone and received audio are different things that can be at different pitches. But for many rigs, when you're transmitting on the same frequency as the station you're listening to, the sidetone pitch and the received audio pitch will be the same.

    I believe "sidetone" means the sound of your keying as you hear it when you're transmitting. If you have a separate transmitter and receiver, or if your sidetone is generated by a standalone keyer or oscillator, there's no reason why the sidetone from the transmitter would have any particular relationship to the received audio frequency. But most modern integrated transceivers keep them the same, assuming you're transmitting at the same frequency as the station you're listening to.

    On my radio, there's a "Pitch" knob, which can be adjusted to change the pitch of the sidetone. As the sidetone pitch changes, the center of the CW filter passband changes, and the offset between the receiver's local oscillator and the frequency display changes, all in a coordinated way, to keep it so that, when your transmission sounds like it's on the same audio frequency as the other station, it really is on the same radio frequency.

    Of course, you can "divorce" this relationship between the sidetone pitch and the received audio pitch by using RIT or XIT controls, if you want.
  10. KC9UDX

    KC9UDX Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    Yep. Some of us have to use our IRT and ITT controls though. :D

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