Very good point, Dick. The 9500 accepts 4 antennas per band segment,
but the user has to manually select the segment.
Jim w8zr
Sent from my iPhone
> On Dec 4, 2016, at 2:08 PM, Dick Green <wc1m73@gmail.com> wrote:
>
> That's a good strategy if you only have one antenna per band, but not if,
> like me, you have multiple antennas and antenna combinations per band. That's
> why I leave AlphaMax on all the time. It's a necessity. Like you, I rarely
> use SSB, so maybe that's why autotune doesn't keep tuning.
>
> Ultimately, the 2000A architecture may make more sense because it allows
> storing tuning parameters for up to 10 antennas per band. No dynamic
> autotune, but it's not necessary unless you vary the power level a lot.
>
> 73, Dick WC1M
>
>> On Dec 4, 2016, at 3:59 PM, MU 4CX250B <4cx250b@miamioh.edu> wrote:
>>
>> 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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>>
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