What must also be considered is processing time for dsp i.f. radios. There
is unavoidable latency in both transmit and receive.
73, Barry N1EU
On Fri, Sep 26, 2014 at 12:24 PM, Bob McGraw - K4TAX <RMcGraw@blomand.net>
wrote:
> The Eagle turn-a-round time, TX to RX is 20ms. Same as for most other
> radios.
>
> The ARRL QST review is incorrect, however the RSGB review is correct.
>
> 73
> Bob, K4TAX
>
>
>
> ----- Original Message ----- From: "Mike Schatzberg" <
> cherokeehillfarm@earthlink.net>
> To: <k9yc@arrl.net>; "Discussion of Ten-Tec Equipment" <
> tentec@contesting.com>
> Sent: Thursday, September 25, 2014 2:33 PM
> Subject: Re: [TenTec] din connector, etc.
>
>
> 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
>>>
>>>
>>> _______________________________________________
>>> TenTec mailing list
>>> TenTec@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>
>> _______________________________________________
>> TenTec mailing list
>> TenTec@contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
>>
>>
>
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|