In practice, is not the ‘mark’ tone continuous?
Silent intervals in between characters might confuse FLDIGI and MTTY – I haven’t used a Flesher in decades, but it might ‘flywheel’ over interruptions like that. (The Dovetrons do
this…) A lot of “physical” TUs use an absense of the Mark tone to turn the motor off after a timed delay – and subsequently turn it back on when the tone re-appears…
Cheers
John KB6SCO
Carson City
From: [email protected] <[email protected]>
On Behalf Of steve bennett via GreenKeys
Sent: Friday, February 7, 2025 9:24 AM
To: greenkeys <[email protected]>; ad7i <[email protected]>
Subject: Re: [GreenKeys] strange behavior FLDIGI
The individual bits were all created with sin(2 * P * f * t) with t starting at zero.
The characters were created by concatenating these mark and space tones. No regard given to joining tones at zero crossings.
In a music application you would want to join at zero crossings to avoid getting a pop sound.
So all bit tones start at zero phase and end when their time slot is up.
No tone between letters. Just silence, start bit, 5 data bits and a stop bit then silence.
As I said the Flesher TU170 has no problem with it.
FLDIGI and MMTTY don't like it.
-Steve AD8CI
On Friday, February 7, 2025 at 11:30:06 AM EST, ad7i <[email protected]> wrote:
When your individual files are concatenated, is the composite signal phase-continuous?
Paul, ad7i
On Fri, Feb 7, 2025 at 11:26 AM John, W9DDD <[email protected]> wrote: