[hpsdr] Using Mercury to monitor final amplifier transmit signal

[Tom Cathey]

Joe,

The "DUP" button was there all the time - just didn't see it.  Top left 
under the MOX button.    It works great!  I can easily see my sampled 8877 
amplifier signal when transmitting now.

This makes the system much more valuable - being able to see the actual 
transmitted signal.  I've made some IMD improvements as a result.  Everyone 
should monitor this high level function when transmitting. Watching the 
display low level signal is always going to be perfect and a fooler to 
what's really going out.


BTW, you mentioned the pre-distorsion topic.   Are you doing some work in 
that area?   Link?

Thanks  again for the help and solution, Joe.

Tom, K1JJ



-----Original Message----- 
From: Joe Martin K5SO
Sent: Friday, February 08, 2013 1:02 AM
To: Tom Cathey
Cc: HPSDR List
Subject: Re: [hpsdr] Using Mercury to monitor final amplifier transmit 
signal

Hi Tom,

Sorry for the confusion.  To run DUPLEX mode with PowerSDR you need to run 
Doug W5WC’s RX1 version of PowerSDR v2.2 (11/24/12).  It has a “DUP” button 
on the front panel that the RX2 version does not have.

When you transmit with the DUP button active your panadapter display shows 
the Rx spectrum during transmit as well as during receive.  By tuning your 
Mercury Rx freq to your Tx freq you may monitor the frequency on which you 
are transmitting.  This displayed signal is the signal that arrives at the 
BNC input connector on Mercury when running in DUP mode.

Works here.

Maybe this info helps?

73,  Joe K5SO


On Feb 7, 2013, at 10:03 PM, Tom Cathey wrote:

> ***** High Performance Software Defined Radio Discussion List *****
>
>
> Joe and Phil,
>
> I tried to disable the signal displayed by Mercury when Penny is 
> transmitting.  It is always there, even when I remove the ant BNC plug off 
> the back of Merc's board.  It appears to be coming in from somewhere else, 
> like thru the board connector.
>
> Is this the way it should be?  Or am I toggled on for the duplex mode 
> without realizing it?  How is the duplex mode enabled?
>
> Bottom line is, with or without an antenna or even a connector on the ant 
> input to the Merc, when Penny is transmitting,  Penny's signal is strong 
> and stable on the Merc pan display. This is with no external amplifier 
> connected. I would like to see this low level signal disappear so that I 
> can then inject some external sampled RF from the amplifier into Merc's 
> ant input.
>
> What am I missing?
>
> Tom, k1JJ
> 

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