----- Original Message -----
From: "Ken Brown" <ken.d.brown@verizon.net>
Hi Michael,
I don't know what version firmware is in my Omni VI version 3 radio.
Maybe it has the "microchirp". No one has complained about it to me.
I'll try listening to it with another receiver to see whether I can
detect a chirp, and I'll also try listening to harmonics to exaggerate
the chirp.
I talked to a friend last night who also has an Omni 6+. He said
that he couldn't hear any "microchirp" on his Omni 6+, so I dunno
what my problem is. During the one test I did, I could definitely hear
it, but I don't find it bothersome (at least not on the fundamental).
BTW, I checked the label on the logic ROM. It says V1.03.
As for as the duty cycle goes, I am seeing pretty darned near
50% duty cycle when the internal keyer speed is at maximum. Gives a dit
plus space duration of about 43 mS. The dits are 20 to 24 mS long
depending on what part of the envelope you call the end of the dit. The
rise time of the dit envelope is about 2 mS and the fall time is about 4
mS.
I see pretty much the same using external keying from my Logikeyer K-3,
although they way I have it set up right now it does not go as fast as
the internal keyer.
Do you have a number I can use to convert dit plus space duration
directly to WPM?
If found some derivations on the internet that suggest that WPM = 2.4
X the dit frequency. The specs on INRAD website say 50ms pulse rep
rate = 48 WPM, which would be consistent with that number (1/50ms
x 2.4 WPM/Hz = 48 WPM). Assuming the above is correct, a 43ms
dit plus space duration would be about 56 WPM, so it sounds like
your Omni 6 is working okay at up to at least 56 WPM. My AEA
MorseMachine will do something like 99WPM when you crank
it all the way up, so I will give that a try when I get a chance.
When I look at it with the Bird 43 and set the power to 90 watts key
down (I can't quite get 100 watts indicated, so I am turning it down to
90 watts) the string of dits measures 30 watts. The Bird 43 scale is not
linear, so this is about 50% deflection even though not 50% power reading.
It just occured to me that the MorseMachine toggles between
the speed knob pot (what I normally use) and the keypad set
speed, so I can probably set the keypad speed to a known
calibrated speed/duty cycle and then just toggle over to it when
tuning with the Omni 6+ in lieu of using the faster Inrad Key
Pulser.
73 de Mike, W4EF.............................
DE N6KB
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