TX Start delayed

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ZL2TLD
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Last seen: 2 years 1 week ago
Joined: 2008/09/05 - 22:13
TX Start delayed

I thought I had seen something in a recent thread similar to my current experience, so reviewed recent posts first.
What I'm getting is different, or perhaps I am perceiving a similar situation in a different manner.

My PC clock is sync'd to better than 100mSec.

Two different situations : TX starts at :00 or :01 and audio within a second thereafter. All FB, no issues. *OR* TX starts at :00 or :01 and audio starts a few seconds later.

Wnen rig goes into TX at xx:x0:00 or 01 but audio does not start until xx:x0:04 or xx:x0:05 :
TX might either terminate at xx:x1:52 as expected *OR* sometimes continues until about xx:x1:56 or xx:x1:57.

So I've either got a sluggish AUDIO start, missing the first few bits of data, but the error correction hides that, RX OK, and tx finishes at x1:52 as expected, *OR* I've got a delayed start and a delayed finish.

09:56 start was tx 09:56:00, audio started 09:56:04, finished 09:57:52.

But an earlier start was TX xx:01, audio started at xx:05 and finished at xx:57

I've never noticed a +4 or 5 DT; maybe that would be too much for the receive algorithm to handle.
I generally get <2 DT, so I'm thinking that the first few bits get dropped somehow on the late start but x1:52 finish, yet with the rest being there, I'm being decoded.

But these few cases I get when tx both starts and finishes a few seconds LATE; my transmission is not decoded. The DT may appear to be about 4, which is too much. So I think that the start of transmission of data is being delayed a few seconds occasionaly, even though PTT is asserted when it should be. (at x0:00)

I am quite willing to accept that the fault is with my ancient P3 500MHz machines running Windows 2000, though I don't need too many people to point that out to me. One (in the know) would be enough. It could well be that my computers are underpowered for the job. I'm simply offering my perceptions for the programmers to consider a potential bug or catch.

So, is anyone else noticing this occasional delay of audio output on an otherwise correctly timed TX? If not, I shall move WSPR to a more modern platform (when I can manage to do so)

de Glenn, ZL2TLD, RE79tb