[hpsdr] Transmit noise problem ?

[Al]

Mike,
    I do Not have the 4 watts out that you measure..  With no drive or 
with full drive and mic at zero, I have less than 4 milli watts out of 
the SDR-1000.  I am not sure what to suggest..   If you unplug the TX 
I&Q ( to line out) from the back of the SDR, do you still have the 
output?   I assume that you do not have the problem with another sound 
card (D44,etc. ).

AL, K0VM


Mike Naruta wrote:
> Yep, David - KM5TZ and I have also observed
> it Al.
>
> I wonder if that's related to the problem
> that I asked about earlier.  I get that
> noise with Janus in transmit.  It's NOT
> RFI; I am into a dummy load, turn the Output
> down to ZERO and I still see 4 WATTS Forward
> on the PowerSDR with the Mic gain at ZERO
> and nothing plugged into the Mic connector.
> In CW there is the same 4 Watts Forward
> with the key UP.  My monitor scope, Bird
> watt meter, and external receiver all verify
> that there is noise all the time in transmit.
> Four watts of RF with no drive is not trivial.
>
> Please give yours a try in transmit Al to
> see if you can duplicate it.
>
>
> Mike - AA8K
>
> "[hpsdr] Transmit noise problem"
>
> "[hpsdr] Janus noise problem?"
>
>
>
> Al wrote:
>> ***** High Performance Software Defined Radio Discussion List *****
>>
>> I don't know if anyone else has noticed this problem but... If I have 
>> the RF gain set in the range of 50-80 then I can here a low level of 
>> high frequency white (?) noise that is independent of the IF 
>> bandwidth.. I do not have this effect with the D44 sound card. Tuning 
>> the RF gain down further reduces the noise to zero.  Turning the gain 
>> up masks the white noise with IF noise.
>> AL, K0VM
>


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