[Elecraft] Turning off Amp PTT when using Tune Button

[HowardZ]

When you buy the SG-500 amp, be sure to also buy the "remote on/off switch".
This remote is also your BAND SELECT switch which also has an AUTO settings.
If SGC would post a picture and description of it, I am sure they'd sell
more of them.
Considering the work it took to design and build it, I think the switch is
worth the money.
The best price is probably at R&L electronics.

Now, you know, sooner or later you are going to forget to switch the
amplifier off before tuning.
Your auto-tuner will then fry when trying to tune with 500 to 700 watts
going through it.
(Yes the SGC 500 can develop over 700 watts - depending on the band in use)
The Palstar AT-AUTO tuner has a PTT input and PTT output - it keeps the
amplifier off both when tuning and also whenever the SWR is below the
threshhold you designate (typically somewhere between 1.5 and 2.0).  The
Palstar is also rated for 1500 watts - any mode.  It's expensive, but it
gets you a perfect SWR - unless your antenna really can't do it.  All the
relay operated auto tuners are a compromise - they are not capable of
adding/removing small enough amounts of inductance or capacitance for a
truely perfect tune - though the relay auto tuners can be lightning fast.

I think all the amps have self protection from high SWR.
You should have some kind of PTT automatic cutoff to protect the tuner from
high SWR while tuning.
I think only Palstar and SGC auto tuners have this protection feature.

Howard


Richard Thorne wrote:
> 
> Kent et All:
> 
> Yes thats the easy and simple way.
> 
> What I was hoping for was quick band changes without the need for 
> flipping switches.  I'll be running an SG-500 amp and already planned on 
> placing a switch in the ptt line to disable the amp.
> 
> Rich - N5ZC
> 
> K9ZTV wrote:
>> Rich . . .
>>
>> Can't comment about other amps, but running the K3 barefoot (or tuning 
>> an external ATU) with the Yaesu Quadra merely requires toggling the 
>> Quadra's OPERATE switch off.  Toggle it back on to use the amp.
>>
>> 73,
>>
>> Kent  K9ZTV
>>
>>
>> Richard Thorne wrote:
>>> Is there a way to turn off the ptt signal to an amp when the TUNE button 
>>> is pushed?
>>>
>>> I want to run high power but I want to disable the amp while tuning an 
>>> external antenna tuner. 
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