So if the ARRL lab test is correct, and the RF delay is 17 ms on the Eagle,
then time to settle receiving again is 70-17=53 ms.
The TS 590S total turn around is only 20 ms.
If you want to break into the transmission, you would have a harder time to do
so with the Eagle transmitting. Normally you could tap one dit or two to break
back in.
What do the keyboard folks do to break a transmission? Hit the letter E? More
than once?
73,
Mike
W2AJI
Sent from my iPhone
>> On Sep 25, 2014, at 3:12 PM, Jim Brown <k9yc@audiosystemsgroup.com> wrote:
>>
>> On Thu,9/25/2014 9:02 AM, Roy wrote:
>> I operate everyday from 35 wpm to 45 wpm with QSK amplifiers. With the
>> built-in Eagle keyer, transmitted weight is perfectly adjustable internally
>> and with an external key or keyboard, weight is also perfectly adjustable
>> using the weight controls on the external keyer to compensate for truncating
>> effect of the 17ms. And again, of course Eagle works QSK with QSK amps.!!!
>
> Thinking more about this -- the ARRL scope traces compare the RF output of
> the rig with the keying signal. This is NOT the same as the output of a power
> amp being keyed by the radio.
>
> I think we need to define a QSK amplifier. There is more than one way to do
> it. The original Ten Tec way -- you key the Titan and the Titan keys the
> radio. The limitation of this setup is that the rig must have a very short
> delay on the RF signal. All amps, including the Titans, accept a DC keying
> signal (either a DC short or +DC). As Rick has noted, amps with vacuum relays
> switch very quickly, and can follow keying to fairly high speeds.
>
> And there's also the matter of what does the operator listen to in order to
> decide if his keying is being shortened. If he listen to sidetone in his
> headphones, that is generated in the rig, and does NOT accurately represent
> the actual output of the rig or the amp. It's only what he's TRYING to send
> with his keyer or key. To hear what we are ACTUALLY sending, we must listen
> on a second radio (with no antenna connected and the RF gain turned all the
> way down)!
>
> Looking at ARRL test reports for the Eagle and the TS590S -- the "TX to RX
> turnaround time" for the Eagle is 70 msec" and 20 msec for the 590. So, as
> Rick noted, at high keying speeds we're not going to hear between the dits,
> even barefoot. For both rigs, there's no shortening of the dits in full QSK
> at 60 wpm, and if the key signal to the power amp is coincident with the
> keying signal to the rig, an amp with a vacuum relay or diode switching
> should reproduce the keying waveforms, while an amp with open frame relays is
> likely to hot switch (unless there's a speedup circuit).
>
> 73, Jim K9YC
>
>
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