Signalink audio level changes with frequency
开云体育It sounds to me like your radio audio circuits do not have a flat response.? For best function, the radio should reproduce audio levels equally across the spectrum, not suppress or enhance different parts of the audio passband at different levels.? That is something that would be good for voice – NOT for digital. If your radio has a microphone equalizer, you may want to zero it out.? My ICOPM has a separate input for digitan that has a flat passband. ? Vy73 - Mike - KD5KC. El Paso, Texas - DM61rt. SOTA W5T-Texas Association Manager.
? ? ? ? ? From: [email protected] <[email protected]> On Behalf Of Tom Schmidt via groups.io
Sent: Wednesday, November 20, 2024 21:54 PM To: [email protected] Subject: [winfldigi] Signalink audio level changes with frequency ? Hi there. When I operate digital modes in FLDigi using my Signalink USB, why does the audio level change when frequency is changed? I'll operate, say, PSK31 on my Yaesu FT-920 at the lower end of the passband at a set audio level. Then, when I change to the higher end of the passband, my audio level will be too high, forcing me to lower it so as not to splatter. When I change back to the lower end of the passband and transmit, my audio level is in the mud, forcing me to turn the audio up. Why is that? ? Tom, N8EUI |
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I am not familiar with this HF SSB Yaesu rig but check this way.
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Do a FLDIGI TUNE (that’s a steady sine wave) on 500 Hz, then 1000 Hz, then 1500 Hz and stop at 2000 Hz, and report to us the power output at these audio frequencies. ?I would never go below 500 Hz nor above 2000 Hz. What power level are you aiming for?
Is the ALC zero at the power level you are running?
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I would tend to keep the average power output on all digital modes (especially RTTY) at 50W or less with zero ALC ?reading on the radio’s dial. Remember psk modes will show an average power well below the peak power (BPSK31, VARA, etc.)
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Your radio is likely in a USB-DATA mode, not USB (PHONE) so the MIC is not live.
The COMPressor should be disabled on all data modes.
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What is the radio’s TX bandwidth setting?
Personally I like to always center close to 1500 Hz audio with a ?1000 Hz bandwidth.
But this is for my ears, not for the sound card input.
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I’ll bet your radio’s TX bandwidth is set to a very narrow level (if the radio has that option).
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de k3eui barry
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On Wed, Nov 20, 2024 at 09:54 PM, Tom Schmidt wrote:
I'll operate, say, PSK31 on my Yaesu FT-920 at the lower end of the passband at a set audio level. Then, when I change to the higher end of the passband, my audio level will be too high, forcing me to lower it so as not to splatter. Hey Tom,
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For many years I was using the "headphones-to-microphone" method to get audio from my PC into my rig. It was noisy, but it worked. But I did notice the same behavior that you are seeing -- if I adjust the audio output levels for 1500 Hz on the waterfall, but then transmit at the lower or higher ends of the waterfall, then levels would be too low or too high.
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The easiest way around this is to use the QSY button in Fldigi, which will adjust your VFO to keep your transmit audio signal at 1500 Hz (or whatever you have defined as the Sweet Spot in the Fldigi config). I even defined a macro in Fldigi that does the QSY and then LOCKs the transmit audio frequency, like this:
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<QSYTO><LOCK:on>
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I've recently switched to using a cheap audio isolation transformer that I picked up from ebay, which allows me to route the audio out from the PC directly into the microphone jack of the rig, and I no longer have the variation of audio levels when I select a different waterfall frequency in Fldigi. Or at least not that I can notice. :)
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Cheers,
Steve K4RVA |
Mike Olbrisch
K3EUI Barry
Steve K4RVA