[hpsdr] angelia questions

[wully]

Hi Abhi, hi all

I have prinicially understood the issue with the microphone: the level 
of the mike input and the according modulation are so weak (with mike 
boost!), as to not reach a significant level. When I pull up the drive 
level to 200, I can see modulation. So, the tlv320 is working ok. What I 
don't understand is the weak levels in comparison to pennylane/mercury 
combination, where the level is much higher.

I have to try to adjust the levels to get reasonable power in tx.

73, hb9epu


On 20.03.2014 13:50, wully wrote:
> Hi Abhi, hi all
>
> since some days I am experimenting with my new angelia. The diversity 
> with the two LT2208 runs ok. But I have two problems, which are not 
> yet clear to me.
>
> 1) A minor problem: the Transmit output is about a factor of four to 
> five smaller, than with the same level when using Mercury/Pennylane 
> (compared by using a tune tone), probably the defining current of the 
> DA-chip is different?.
>
> 2) A more serious problem: the microphone does not work. When 
> activating the mike, I see a noise pedestal in the parallel active rx, 
> but when speaking into the mike, no change of this noise pedestal is 
> occuring.  When using the same software, the same mike on my hermes 
> (TAPR), the modulation is clearly seen. So, it does not seem to me a 
> software problem (mike boost is actively set through the 
> USB-Protocol). The configuration of the mike input is the same in both 
> cases (an Electret mike, using the bias).
>
> I will further investigate.
>
> Comments about this behavior are welcome.
>
> 73, hb9epu


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