> A linear transmitting amp for hams is not dealing with the additive
> effects of hundreds of signals.
.... or the very high peak to average ratios of multi-carrier digital
signals.
73,
... Joe, W4TV
On 7/1/2010 8:25 AM, Carl wrote:
> 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
>>> _______________________________________________
>>> Amps mailing list
>>> Amps@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>>
>>
>>
>>
>> --
>> Saandy
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|