Re: LF: Cats among pigeons

[Andy Talbot <andy.g4jnt@gmail.com>]

In all cases, the mean power is 4dB above the noise level in a
bandwidth corresponding to 1/symbol interval

Andy  G4JNT


On 12 February 2012 10:15, qrss <qrss@talktalk.net> wrote:
> Thanks for posting the info Albert, that is what was needed.
>
> I assume Av is the average of the minimum signal levels obtained from the
> large number of test.
>
> 73 Eddie G3ZJO
>
>
> On 12/02/2012 09:42, Albert wrote:
>>
>> Hello all Opera lovers,
>>
>> Testing Opera speed op1 till op32 under "lab" conditions without the real
>> world phenomena like fading and QRN.
>> The results:
>> 1. if you have solid Opera decodes the received SNR stays the same when
>> switching between opera speeds;
>> 2. the only change is the minimum level where decodes are still possible.
>> After a large number of test transmissions I gathered the following
>> results.
>>
>> Op1   decode @ -24dB Av
>> Op2   decode @ -27dB Av
>> Op4   decode @ -30dB Av
>> Op8   decode @ -33dB Av
>> Op32 decode @ -37dB Av
>>
>> Test set up: TX Flex 1500, 0.2 mw output, attenuators Bird and HP > 120
>> dB, min. step 1 dB, RX Flex 5000, Software Opera v.1.2.8 Windows 7 64.
>>
>> 73, Albert PA0A
>>
>>
>>
>>
>
>