[hpsdr] angelia questions

[wully]

Hi Tim

Thank you. I have testwise powered the mic bias by +5V supply. This has 
given a good effect.
But I don't understand, why I have not had such needs with 
pennylane/penelope.

I will have to carefully check all levels...

73, hb9epu

On 20.03.2014 20:29, Tim ORourke wrote:
> This looks to be a bias issue, somehow bias is not getting to mic element.
> Check jumpers on motherboard.
> Tim
>
>
> -----Original Message-----
>> From: wully <wully at bluewin.ch>
>> Sent: Mar 20, 2014 3:20 PM
>> To: hpsdr at lists.openhpsdr.org, Abhi A <abhiarunoday at gmail.com>
>> Subject: Re: [hpsdr] angelia questions
>>
>> ***** High Performance Software Defined Radio Discussion List *****
>>
>> 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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>
> Tim O'Rourke
> W4YN at ARRL.Net
> Low Power Amateur Radio Rocks
> Member of Flying Pigs,ARCI,GQRP,RSGB,ARRL Life Member
> NHRA Life Member


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