[Elecraft] Measuring power output of an SSB transmitter

[Stewart Baker]

My PEAK  power is down by about 50% as measured on an 200MHz 
oscilloscope when the COMP is set to 0. This can't be right..

73
Stewart G3RXQ
On Mon, 28 Apr 2008 22:25:36 -0700 (PDT), Paul G4LNA wrote:
>
> I quite agree with you Brian, I didn't think there was any other 
way of
> monitoring SSB reliably. I've always used a scope way back when 
I used to
> build AM transmitters and I have one permanently connected so I 
can keep an
> eye on what's going on, meters tell lies I find.
>
> 73 Paul G4LNA.
>
>
> Brian Lloyd-6 wrote:
>
>> There is no substitute for an oscilloscope. There are precious 
few
>> meters that will read true peak power. Also, no meter is going 
to show
>> you peak compression or outright flat-topping (clipping) like a 
'scope.
>>
>> Someone mentioned that their power output went down when they 
turned
>> the compression down and would Elecraft make power output 
remain
>> constant as compression is reduced. Well, the power output 
(average)
>> is *SUPPOSED* to decrease when you reduce compression. When 
speech
>> compression is reduced, your peak-to-average power ratio 
increases.
>> The peaks remain just as high but the average power is 
considerably
>> less. This is another reason to want a 'scope to check your 
rig.
>>
>> BTW, how many people have done a two-tone test or a double 
trapezoid
>> test for linearity? How many people even know what I am talking
>> about? :-)
>>
>> (My first HF transmitter was a Central Electronics Multi-Phase 
exciter
>> with a whopping 10W of output. When I got done making that work 
again
>> you can bet I understood single-sideband. :-)
>>
>> Brian Lloyd
>> Granite Bay Montessori School          9330 Sierra College Bl
>> brian AT gbmontessori DOT com          Roseville, CA 95661
>> +1.916.367.2131 (voice)                +1.791.912.8170 (fax)
>>
>> PGP key ID:          12095C52A32A1B6C
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A32A 1B6C
>>
>>
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