[hpsdr] angelia questions

[Tim ORourke]

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
>
>_______________________________________________
>HPSDR Discussion List
>To post msg: hpsdr at openhpsdr.org
>Subscription help: http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org
>HPSDR web page: http://openhpsdr.org
>Archives: http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/


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

 1395343771.0