[Elecraft] First test of LP-Pan on K3 with emu0202

[Edward R. Cole]

Update to my earlier e-mail:

The emu soundcard was apparently uninstalled by my computer (when I 
turned off power on the soundcard).  After a couple hours I came back 
to make more tests and found it non-functional; it was no longer 
listed as hardware in the computer.  Drivers were gone.

So I decided to re-install it, but this time I disabled the embedded 
soundcard on the mother board.  Install went well (in fact better as 
the first time I installed it halted during the install - but gave me 
instructions to restart the computer typical for installing drivers).

Well, this time it now plays with a flat spectrum and appears to have 
more gain with signals from the K3+LP-Pan.  Overall the display and 
function seems more "normal" compared to how the SDR-IQ runs on this 
sw (Spectravue).  Noise floor (antenna connected) is still running 
-62 dBm vs -106 dBm for the SDR-IQ.  Maybe a difference in gain 
between the two receivers, or the sw reacts differently on the two receivers?

Going to write Larry at Telepost for his opinion as the 
K3+LP-Pan+emu0202 is a standard set up.

I compared the two LP-Pan units and one seems to have a few dB more 
output but not a significant amount.

The next step is to install the Delta-44 4-port soundcard (requires 
opening the computer to install the PCI card).  The Delta-44 handles 
four audio inputs (two I/Q pair per LP-Pan) needed for running 
diversity SDR from both main-Rx and sub-Rx (which will require 
surgery for breaking out the IF).  The Delta can be run with the same 
IF coupled to both LP-Pan for testing.  That will leave surgery as 
the last step in my project.
http://www.kl7uw.com/LINRAD.htm

73, Ed


>Date: Sun, 30 Jan 2011 17:38:22 -0900
>To: Moon-Net
>From: "Edward R. Cole" <kl7uw at acsalaska.net>
>Subject: First test of LP-Pan on K3 with emu0202
>Cc: Elecraft Reflector
>
>I installed the emu-0202 USB soundcard today and interconnected one 
>of the LP-Pan which was connected to the main-RX IF.  I used 
>Spectravue as SDR sw since it was already installed for my 
>SDR-IQ.  I didn't run into many hurdles and had 20m being displayed 
>at 96-KHz bw.  It took a little getting accustomed to the display 
>being relative freq. offset to the radio dial.
>Bonus is I have audio playing from my computer speakers again (via 
>the direct monitor).  I did discover that the SDR-IQ has the 
>opposite convention for deciding I and Q input but was easily 
>swapped in the sw (R=q, L=I on the LP=Pan while Spectravue wants 
>them reversed).
>
>It is also nice to have audio on my computer, again.  Both computer 
>sourced audio and the LP-Pan are mixed in the emu, so one would want 
>to mute the computer when running the K3+LP-Pan.
>
>I noticed a pronounced bandpass curve in the noise leve which was 
>pretty high (-62 dBm).  I had to run the emu input gain at 95% full 
>setting so wonder if that is normal?  I haven't tried the other 
>LP-Pan for comparison.  I wonder if the passband is an artifact of 
>the LP-Pan or the front end of the K3?  I am kind of spoiled with 
>the SDR-IQ which displays a flat spectrum.
>
>I have not tried LInrad as the SDR sw, though it is installed on my 
>computer.  I have the Delta-44 soundcard to install and second IF 
>(sub-Rx) to make.
>
>But a good first step!
>
>73, Ed - KL7UW, WD2XSH/45
>======================================
>BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
>EME: 144-1.4kw*, 432-100w*, 1296-testing*, 3400-winter?
>DUBUS Magazine USA Rep dubususa at hotmail.com
>======================================
>*temp not in service


73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
EME: 144-1.4kw*, 432-100w*, 1296-testing*, 3400-winter?
DUBUS Magazine USA Rep dubususa at hotmail.com
======================================
*temp not in service