[hpsdr] Mercury sensitivity problem

[Jose V. Gavila]

Hi again,

I have been checking the Mercury schematics and my first suspect is the 
preamplifier (LTC6400-20). I am going to check with cold and heat, to 
see if I can reproduce the problem that way.

If so... is it an easy to get part?

Regards,

JOSE

El 08/09/2012 10:57, Phil Harman escribió:
> Hi Jose,
>
> Check the input relay that switches the 20 dB attenuator in/off circuit
> for a possible dry joint.  Do you hear a 'click' when you select the
> attenuator in PowerSDR?
>
> 73 Phil...VK6APH
>
>
>
> -----Original Message----- From: Jose V. Gavila
> Sent: Saturday, September 08, 2012 4:52 PM
> To: hpsdr at lists.openhpsdr.org
> Subject: [hpsdr] Mercury sensitivity problem
>
> ***** High Performance Software Defined Radio Discussion List *****
>
> Hi all,
>
> I have just got a barely used set of Mercury-EU + Metis + Atlas and have
> got it working fine with last svn release of PowerSDR 2.2.3. I had
> previously checked with a previous 2.2.3 version, but the problem is the
> same: it starts OK, receiving with a good sensitivity. Then, from time
> to time, sensitivity drops a lot (about 4 or so S-meter units), so you
> can only receive strong signals. Then, sometimes, it gets back to normal
> and sometimes is stays that way.
>
> I have 20+ years of experience in radio and 10+ fixing all kind of rigs
> (in fact, now I work full time on that), and my gut feeling is that
> there is an analog problem in the unit, due to a bad soldering joint or,
> what I am afraid, a aproblem on the A/D
>
> Is there a way to check (by software) my Mercury to be sure where is the
> fault located?. At the end, I can resort to schematics and treat this as
> any other rig but, if there are software tools, I would prefer that
> approach as a first attempt to pinpoint the fault.
>
> Thanks for your help and best regards,
>
> JOSE
>


-- 
73 EB5AGV - JOSE V. GAVILA - IM99sm La Canyada - Valencia(SPAIN)
    http://agvradio.com  AGVradio
    http://jvgavila.com  Personal WEB

 1347127608.0