[hpsdr] Fwd: Re: cycling of PS

[K4KV]

Success!

I turned off auto-attenuate.  I happen to know, through experimentation,
that certain step-attenuator values

seem to work 'reasonably'.  Namely, 10db, and 16db.  I think I set is at
16db and tried again with a two-tone

test.  That worked.  I saw a steady green and a yellow level.

73

Glen K4KV



On 8/4/2017 23:40, Warren C. Pratt wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> Hi Glen and Bill,
>
> PSDR sends the same commands whether the attenuator is 5-bit of 6-bit 
> -- it has no knowledge of that specific in the hardware. However, I 
> recall other cases that the 6-bit part did not work correctly.  I 
> remember looking at the datasheet one time and thought that the 6-bit 
> part should work; however, I recall problems with it.
>
> Here's a test you can run on your board with the 6-bit part. Apply a 
> signal well above the noise floor and  of steady amplitude to the 
> input.  Now, adjust the S-ATT in 1dB steps.  The S-meter and 
> panadapter should show the same amplitude independent of the 
> attenuator setting because PowerSDR automatically adjusts those 
> amplitudes for the attenuator setting.  If that does not happen, then 
> the 6-bit part is not working correctly.
>
> 73,
>
> Warren  NR0V
>
>
> On 8/4/2017 6:12 PM, Bill Diaz wrote:
>> ***** High Performance Software Defined Radio Discussion List *****
>>
>> Glen,
>>     What radio model do you have?
>> Bill KC9XG
>>
>> On 8/4/2017 5:43 PM, K4KV wrote:
>>> ***** High Performance Software Defined Radio Discussion List *****
>>>
>>> Bill,
>>>
>>> I see what is happening, and think I know why it is going wrong.
>>>
>>> I tried it at 50-100W level, and it works fb with the input 
>>> attenuator at 0db.  It also works fb with 12% drive to
>>>
>>> the amp and 600W out.
>>>
>>> As soon as I exceed that power level, it goes into a cycling mode.  
>>> Up and down flashing all over the place.
>>>
>>>
>>> I had reported, and others have reported that PSDR does not handle 
>>> my 6-bit attenuator, but I have a board with
>>>
>>> a 5-bit attenuator and it works as it should.  When the program 
>>> attempts to start raising the attenuator value to
>>>
>>> reduce the PS input level, who knows what the attenuator is really 
>>> doing.  I have seen the attenuator in rx mode
>>>
>>> jump all over the place, incrementing 1 db at a time.
>>>
>>> This 6-bit attenuator does not do this in Thetis, and works well.
>>>
>>> I am going to uncheck the auto-attenuate box and try my own attempt 
>>> at limiting the PS input signal for full amp
>>>
>>> output...
>>>
>>> 73
>>>
>>> Glen K4KV
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