[Amps] ICOM PRO III QSK

[Larry Benko]

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 at yahoo.com>
>> Sent: Wednesday, December 07, 2011 11:12 AM
>> To:<amps at 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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