Larry.. I observed the same timing on my 7000. But if you measure T8, (8
volts on transmit) I think you will find that the RF does not continue after
T8 goes back low. I also measured the 7200. T8 is about the same on it.
T8 controls the transmitter. I don't think that RF COULD flow after T8
disappears.
73
Jim W7RY
--------------------------------------------------
From: "Larry Benko" <xxw0qe@comcast.net>
Sent: Friday, December 09, 2011 8:10 AM
To: <amps@contesting.com>
Subject: Re: [Amps] ICOM PRO III QSK
> Joe,
>
> I made measurements on a lot of transceivers which can be seen at
> http://www.w0qe.com/amplifier_timing.html
>
> It needs a little updating but might be useful.
>
> 73,
> Larry, W0QE
>
> On 12/9/2011 8:12 AM, Joe Subich, W4TV wrote:
>> I don't have the link at hand or time to go looking for it right now
>> but I've seen a rather extensive examination of T/R switching that
>> shows the Icom rigs generally hot switch on returning to receive in
>> QSK when using the "SEND" or "HSEND" line from the ACC jack. That
>> is, the SEND/HSEND signal releases roughly 5 ms *before* the Icom
>> transceiver stops producing RF.
>>
>> Drive to the "send" relay includes roughly 5 ms delay necessary to
>> prevent early release of the amplifier relay. AD5X has a circuit for
>> the ACC output at; www.ad5x.com/images/Articles/QSK%20Delay.pdf.
>>
>> An amplifier with vacuum relays will need at least 10 ms delay - 5 ms
>> to overcome the "early" release on the SEND line plus 5 - 7 ms for
>> normal operation.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>> From: "rick darwicki"<n6pe@yahoo.com>
>>> Sent: Wednesday, December 07, 2011 11:12 AM
>>> To:<amps@contesting.com>
>>> Subject: [Amps] ICOM PRO III QSK
>>>
>>>> Hi all,
>>>>
>>>> Does anyone know it the timing on the ICOM PRO III linear amplifier
>>>> SEND
>>>> line is such that the AMP will not be hot switched on FULL BREAK IN?
>>>>
>>>> I have an old Alpha 76 and can install vacuum relays for QSK if the
>>>> timing
>>>> is OK out of the PRO III.
>>>>
>>>> Thanks,
>>>>
>>>>
>>>> Rick, N6PE
>>
>> _______________________________________________
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>> http://lists.contesting.com/mailman/listinfo/amps
>>
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