[TenTec] Orion and amplifier fault

[Bruce Small]

Good to know. Thanks!!

Bruce KM2L

On 8/10/2021 2:20 PM, Barry N1EU wrote:
> There was a similar, but not quite the same, issue where the original 565
> caused arc fault errors in Acom amplifiers.  The 565's bipolar PA output
> transistors seemed to be the cause and the problem disappeared with the 566
> that used different (FET) output transistors.  The work-around back then
> was to use a high pass filter between the 565 and the Acom.  That
> eliminated the arc faults, which seemed to be related to low frequency
> spurs in the 565 rf output.
>
> 73, Barry N1EU
>
> On Tue, Aug 10, 2021 at 11:06 AM Bruce Small <brucesmall73 at gmail.com> wrote:
>
>> I need to tap the collective wisdom of this group regarding an
>> interesting problem.
>>
>> I have an ACOM 700S solid state amplifier that is driven either by an
>> Orion (565) or an Orion II (566).
>>
>> When I use the 565, the amp faults on 10 meters only. The protection
>> fault indicates high SWR and excessive drive current. This happens
>> regardless of the amount of drive power from the Orion, even with the
>> PWR control turned all the way down, providing about 6 watts of drive.
>> On CW, the fault occurs on key-down, while on SSB and FT-8 the amp
>> faults on key-up, at the end of a transmission. Engaging the TUNE button
>> does not produce the fault. All bands other than 10 meters work normally.
>>
>> Using the O II, none of this behavior occurs, and the amp plays happily.
>>
>> Steps taken without solving the problem include:
>> *Replace coax jumpers  (they needed it anyway)
>> *Replace arc plug in lightning arrestor
>> *Remove all components from the signal path (watt/SWR meter, tuner, coax
>> switch, lightning arrestor) and connect directly to the coax run to the
>> antenna
>> *Connect to a different antenna fed through a separate coax cable
>> *Control the amp using Keying Loop 1, Keying Loop 2, or the Amp Key output
>> * I don't have a good oscilloscope, but to the best of my ability to
>> observe, the CW waveform was well-shaped and didn't show any spikes in
>> power.
>>
>> All of this points to an issue with the Orion on 10 M - what else should
>> I look at?
>>
>> Thanks & 73,
>> Bruce KM2L
>>
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