Celluar amps operate over a multi channel bandwidth with many signals as do
CATV line amps and your typical rice box transceiver receiver section.
A linear transmitting amp for hams is not dealing with the additive effects
of hundreds of signals.
Carl
KM1H
----- Original Message -----
From: "Saandy Eban" <alexeban@gmail.com>
To: "Colin Lamb" <k7fm@teleport.com>
Cc: <Amps@contesting.com>
Sent: Thursday, July 01, 2010 3:05 AM
Subject: Re: [Amps] 1 db compression point procedure ?
> ...Point is, the 1dB compression point can be 5-10 dB below our usual
> operating conditions.
> it has more to do with low level amplifiers than with high power ones.
> low level amplifiers have to cope with myriads of signals coming from the
> antenna and they are supposed to generate as few intermodulation products
> as possible!
> high power amplifiers have to cope only with their own internal
> nonlinearities, so they depend more on the drive levels and correct
> operating points. to analyze these products, the 2 tone test is more
> representative.
> i can tell you that in order to operate close to the 1dB compression
> point cellular amplifiers operate at about 10% of their rated maximum
> power.
> not very effective from our point of view.
> Alex 4Z5KS
>
> On Wed, Jun 30, 2010 at 11:23 PM, Colin Lamb <k7fm@teleport.com> wrote:
>
>> How to know when you have reached the 1 db compression point!
>>
>> Find a qso with both stations having strong signals. QSY about 20 kHz
>> away
>> and put your station on the air with a test and whistling often into the
>> mike. Then listen on your frequency. Keep turning up the mike gain.
>>
>> When the ham that was 20 kHz away comes onto your frequency and hurls
>> insults at you, then you know you have reached the 1 db gain compression
>> point.
>>
>> 73, Colin K7FM
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>>
>
>
>
> --
> Saandy
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