[hpsdr] MERCURY

[FRANCIS CARCIA]

Preamp is on because my RX does not function with it off. 

--- On Sat, 12/27/08, Richard Stasiak <rstasiak at sympatico.ca> wrote:

From: Richard Stasiak <rstasiak at sympatico.ca>
Subject: Re: [hpsdr] MERCURY
To: carcia at sbcglobal.net
Date: Saturday, December 27, 2008, 9:16 PM


Hi Francis 


I only have one signal generator so I can't test the 20 khz test. Did you have the preamp on?


Rick



On 27-Dec-08, at 9:08 PM, FRANCIS CARCIA wrote:






well pretty quiet on 160 so far tonight so ran some quick numbers. First I don't trust my numbers unless they are the same three times. Also rough readings may be off a couple dB. 
1. MDS on 75M about -136 with 500 Hz filter iin CW mode. Noise floor about -140 dBM.
2. Two tone dynamic range two signals 3.870 and 3.890 MHz.
         Spur comes out of the noise floor when both signals hit -80 dBM so pretty crappy
         around 60 db dynamic range. I notice weird effect so run levels higher. When both     
          Run up to -27 dBM spur at -121 dBM  (approx 94 dB)
3. Then I selected "dither enabled" Spur now comes out of the noise floor at about -65 dBM
         so about 70 dB dynamic range. At -30 dBM signals spur is at -120 dBM 
         (about 90 dB dynamic range)
4. Now I also turn on "random enabled" With both signals at -40 dBM the spur is in the 
        noise. I then increased the signals to -25 dBM bringing the spur up to -130 dBM.
        (dynamic range 105 dB)
Test configuration 2 HP8640B generators with the same HB combiner I've been using for 30
years. 6 db pads on all three ports.    
Yup, this looks interesting guys. 
 
 
 
--- On Sat, 12/27/08, Richard Stasiak <rstasiak at sympatico.ca> wrote:

From: Richard Stasiak <rstasiak at sympatico.ca>
Subject: Re: [hpsdr] MERCURY
To: "Graham / KE9H" <KE9H at austin.rr.com>
Cc: "Jerry Flanders" <jeflanders at comcast.net>, hpsdr at lists.hpsdr.org, carcia at sbcglobal.net
Date: Saturday, December 27, 2008, 7:16 PM

>>
>> Do we need filters on Mercury to attenuate unwanted  
>> "subharmonic" (or whatever it is called) responses?
> It depends what your antenna system is feeding to Mercury.  I am  
> running it
> without input filter on a low multi-band dipole, and it generally  
> works just fine.
> It is a pretty robust receiver, barefoot.
> If you are close to a broadcast transmitter location, or you have a  
> high
> wideband antenna, your results might be different.

I have had just a few hours with Mercury now (barebones card, no input  
filters) with various antennas.  I am amazed at its capabilities.  On  
160m it blows the socks off my SDR1000....... don't even need to  
switch on the bci filter.

Mercury is a keeper!

Need to interface that 100w amp I have been saving, to get this rig on  
the air.

73

Rick ve3mm 

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