I don't think the autotune in the 9500 is oversensitive to impedance
variations. It's rather that the optimal tuning point depends on the
drive level. If you tune the 9500 with, e.g., 20 Watts of drive, it
will tune for maximum output and efficiency at that drive. If you
increase the drive to, say, 40W, the optimal tune and load settings
will be substantially changed. It's normally best to autotune the amp
for its rated output of 1500W, then turn off the autotune and save
that setting. That way you won't be causing the autotune to hunt if
you lower the drive power. I seldom use SSB, so don't know if the
autotune tries to follow fluctuating voice peaks. I hope not!
73,
Jim w8zr
Sent from my iPad
> On Dec 4, 2016, at 1:43 PM, Dick Green <wc1m73@gmail.com> wrote:
>
> Strange that the factory recommends keeping autotune off. I've never found
> that to be necessary with the 87A. Once it finds a match, the autotune stops
> hunting. Could be that they're concerned about antennas that are harder to
> match than mine, which are all resonant at the operating frequency. That
> said, I my understanding is that the 9500 autotune is considerably faster
> than the 87A, so maybe it's more sensitive to slight impedance variations.
>
> 73, Dick WC1M
>
> 73, Dick WC1M
>
>> On Dec 4, 2016, at 12:48 AM, Bill Turner <dezrat@outlook.com> wrote:
>>
>> ------------ ORIGINAL MESSAGE ------------(may be snipped)
>>
>>> On Sat, 03 Dec 2016 19:08:33 -0800, Paul wrote:
>>>
>>> I believe the Alpha will auto tune if it wants to based
>>> on poor SWR, but the ACOM only auto tunes when you ask it to.
>>
>> REPLY:
>>
>> The Alpha 9500 can be left in autotune mode, but the manual recommends
>> against it because of continuous "hunting" for a match. This no doubt
>> will cause excessive wear on the stepper motors too.
>>
>> Best to tune it once and shut off autotune. That's what I do and it
>> works fine.
>>
>> 73, Bill W6WRT
>>
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