Re: [Flexradio] 1.3.10 and now 1.3.11 image rejection on transmit (fwd)

2005-06-25 Thread Robert McGwier 


Klaus:

Frank and I wrote the code that does the smaller buffer sizes in the dsp 
and in the console and I have
done this several  times.  Yesterday I argued with Eric that we had a 
serious problem as you had
pointed out until I remembered that the receiver IQ balance is not the 
same as a perfect TX
recording.  This was despite the evidence of my ears where I could find 
no image on a receiver
right next to the transmitter.  This is new to all of us and we are 
giving ourselves an enormous
amount of control over the operation of the radio.  This has great 
positive impact but can be
a little dangerous.  The number of controls and settings is really 
growing.  We are really in

need of 1.5.X and its reorganized console approach.

Glad you got it fixed.

Bob


Klaus Lohmann wrote:


Bob and others,

my apologies - I found the problem which has been as expected originated "between 
the headphones". The reason was an abnormal low buffer setting of 64 at the DSP Tab 
... please forgive me.

73 - Klaus, DK7XL

Re: [Flexradio] 1.3.10 and now 1.3.11 image rejection on transmit (fwd)

2005-06-25 Thread Klaus Lohmann 
Bob and others,

my apologies - I found the problem which has been as expected originated 
"between the headphones". The reason was an abnormal low buffer setting of 64 
at the DSP Tab ... please forgive me.

73 - Klaus, DK7XL




---Ursprüngliche Nachricht---
From: "Klaus Lohmann" <[EMAIL PROTECTED]>
To: "Robert McGwier" <[EMAIL PROTECTED]>,"FlexRadio" 
Subject: Re: [Flexradio] 1.3.10 and now 1.3.11  image rejection on transmit

Bob and others,

let me remind that also the AGC in my setup with versions starting 1.3.9a is 
almost not working and that the TX-signal is completely out of the TX-filter 
limits. My setup: 3-board-stack, Delta44 (no preamp, no addditional 
soundcard)XP, SP2 

My second 3-board-stack is running Audigy2 ZS - using 1.3.9a/10/12 with no 
problems.

To demonstrate and compare the TX signals using 1.3.8 and 1.3.12 (both Delta44) 
please have a look at the pictures shot from my second SDR. The TX is almost 
quite, only random noise in the shack is driving. TX-filter limits are 
identical (170Hz - 3000Hz). You may notice the brickwall shape in 1.3.8 and the 
carrier that can be easily identified.  

73 - Klaus, DK7XL




"Robert McGwier" <[EMAIL PROTECTED]> schrieb:
> Klaus and others:
> 
> We ran extensive tests.  On the wave file player, on the air,  everywhere.
> There is not a single thing we could do to reproduce the image problem.
> With the SDR-1000 transmitting 1W and the Elecraft K2 right next to it,
> the main energy lobe is S8-S9.  The opposite sideband is not hearable.
> Eric ran the tests in the lab.  We simply cannot reproduce this in anyway.
> 
> I used both a four board stack and a 3 board stack that is waiting for
> me to upgrade (Tom Clark's).
> 
> Try to record a wave file of the test signal and let me play it.
> 
> Bob
> 
> 
> 
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