[Amps] ICOM PRO III QSK

[Jim W7RY]

Here is the site I was thinking of:

http://w0qe.com/amplifier_timing.html


73
Jim W7RY


--------------------------------------------------
From: "Joe Subich, W4TV" <lists at subich.com>
Sent: Friday, December 09, 2011 8:01 AM
To: "Jim W7RY" <jimw7ry at gmail.com>
Cc: "rick darwicki" <n6pe at yahoo.com>; <amps at contesting.com>
Subject: Re: [Amps] ICOM PRO III QSK

> 
> > I have seen that too but it was strictly limited to the IC-7000.
> 
> The study I saw (not the AD5X article) was not limited to the IC-7000.
> The "premature release" applied to all of the "small" radios 706/7000
> as well as several of the full size radios - including 7700, 746Pro,
> and I believe the ProIII - when using the ACC jack instead of the
> Send relay.
> 
> 73,
> 
>    ... Joe, W4TV
> 
> 
> On 12/9/2011 10:36 AM, Jim W7RY wrote:
>> I have seen that too but it was strictly limited to the IC-7000.
>>
>> 73
>> Jim W7RY
>>
>>
>> --------------------------------------------------
>> From: "Joe Subich, W4TV" <lists at subich.com>
>> Sent: Friday, December 09, 2011 7:12 AM
>> To: "rick darwicki" <n6pe at yahoo.com>; <amps at contesting.com>
>> Subject: Re: [Amps] ICOM PRO III QSK
>>
>>>
>>> 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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>>
>>