I connected the 575 to the Acom. At about 14 watts of drive, I got "hot
switching" fault and radio started smoking. Here is email string with
Acom.
No - I've just seen the data on the radios. You are hot-switching the
output of the transceiver when un-keying. But the RF waveform has
decayed, just not all the way to zero when the amp unkeys. This
normally results in key clicks. But depending on the actual transceiver
power when the amp unkeys, this could be hard on the transceiver.
Phil
----- Original Message ----- From: "Steve Rutledge"
<gatorman71@bellsouth.net>
To: "Phil & Debbie Salas" <dpsalas@tx.rr.com>
Cc: "Jay Terleski" <info@arraysolutions.com>; "'Phil Salas'"
<psalas@arraysolutions.com>; "'Bob Naumann W5OV'" <BobN@arraysolutions.com>
Sent: Tuesday, May 25, 2010 9:25 PM
Subject: Re: N4JQQ - Amp Question
Tks Phil.
Have you ever had a report of an ICOM seriously smoking after
the Acom sensed the hot switching on 6m?
Trying to correlate what's going on here.
Steve
On 5/25/2010 8:09 PM, Phil & Debbie Salas wrote:
Steve - At least some ICOM radios have this problem where the amp is
unkeyed BEFORE RF decays to zero. See
http://w0qe.com/amplifier_timing.html. We also have data from ICOM
showing that this problem occurs in the IC-7600. We solved this problem
by having a strapping option in the QSK MASTER which delays the turn-off
time of the QSK MASTER relays to approximately 10ms.
Phil
----- Original Message ----- From: "Steve Rutledge"
<gatorman71@bellsouth.net>
To: "Jay Terleski" <info@arraysolutions.com>
Cc: "'Phil Salas'" <psalas@arraysolutions.com>; "'Bob Naumann W5OV'"
<BobN@arraysolutions.com>
Sent: Tuesday, May 25, 2010 7:33 PM
Subject: Re: N4JQQ - Amp Question
> Jay, I'm still trying to understand this. Is this the problem that
> Icom radios seem to be famous for? My HF amps are Kenwood. I guess
> I'm trying to figure out why my radio started smoking when the "hot
> switching" fault shut everything down. Have you actually had reports
> of Icom 575 radios doing this before with the Acom 1000? Are all the
> typical keying lines that you see being sold for Icom radios and amps
> taking care of the same issue? Sorry for all the questions, I just
> have never encountered anything like this before.
>
> Regards,
>
> Steve
>
> On 5/24/2010 12:55 PM, Jay Terleski wrote:
>> Steve,
>> Some radios do not drop the RF envelope before the PTT line is
>> dropped. This
>> is certainly the issue with this 575H you have.
>> We make the QSK Master, which includes a provision to maintain the
>> PTT line
>> duration into the amp by moving a jumper. It is one way to solve this
>> problem with this transceiver.
>> Jay
>>
>> -----Original Message-----
>> From: Steve Rutledge [mailto:gatorman71@bellsouth.net]
>> Sent: Sunday, May 23, 2010 6:31 PM
>> To: Jay; Jay Terleski
>> Subject: N4JQQ - Amp Question
>>
>> Have you had reports of your amps displaying 'HOT SWITCHING' while
>> tuning on
>> 6m?
>> 3 times I have tried to drive the Acom 1000 on 6m with an ICOM 575H.
>> At some point the Acom displays 'HOT SWITCHING', sometimes with as
>> little as
>> 14W drive.
>> Once I have also had the ICOM radio begin to smoke, most likely from the
>> filter section
>> of the transmitter output.
>> Could this be some sort of oscillation that's being created between
>> exciter&
>> Acom?
>> Is there a recommended limit on the length of coax between the
>> exciter and
>> Acom?
>> I have tried 2 different lengths of cable and had it happen with both.
>>
>> The amp appears to have suffered no ill effects. It works great with a
>> Kenwood TS-690S driving it with 50 watts.
>>
>> Steve, N4JQQ
>>
>>
>>
>>
>
Steve,
Some radios do not drop the RF envelope before the PTT line is dropped. This
is certainly the issue with this 575H you have.
We make the QSK Master, which includes a provision to maintain the PTT line
duration into the amp by moving a jumper. It is one way to solve this
problem with this transceiver.
Jay
-----Original Message-----
From: Steve Rutledge [mailto:gatorman71@bellsouth.net]
Sent: Sunday, May 23, 2010 6:31 PM
To: Jay; Jay Terleski
Subject: N4JQQ - Amp Question
Have you had reports of your amps displaying 'HOT SWITCHING' while tuning on
6m?
3 times I have tried to drive the Acom 1000 on 6m with an ICOM 575H.
At some point the Acom displays 'HOT SWITCHING', sometimes with as little as
14W drive.
Once I have also had the ICOM radio begin to smoke, most likely from the
filter section
of the transmitter output.
Could this be some sort of oscillation that's being created between exciter&
Acom?
Is there a recommended limit on the length of coax between the exciter and
Acom?
I have tried 2 different lengths of cable and had it happen with both.
The amp appears to have suffered no ill effects. It works great with a
Kenwood TS-690S driving it with 50 watts.
Steve, N4JQQ
On 5/26/2010 9:16 AM, W6OAL@aol.com wrote:
> Steve,
> Why would there be a problem?
> CU 73, Dave...
> In a message dated 5/25/2010 11:01:40 P.M. Mountain Daylight Time,
> crownhaven@bellsouth.net writes:
>
> Anyone ever tried to use an Icom 575H with an Acom 1000???????
>
> Thanks,
>
>
> Steve, N4JQQ
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