[Elecraft] New transmit monitor

Tue May 19 19:13:03 EDT 2015

Any way to get that a menu option that we can turn on and off as desired?

      From: Alan <n1al at sonic.net>
 To: elecraft at mailman.qth.net 
 Sent: Tuesday, May 19, 2015 5:37 PM
 Subject: Re: [Elecraft] New transmit monitor

The signal that the P3 receives when the K3 is in transmit mode is due 
to random leakage of the transmit IF signal out the K3's IF OUT 
connector.  One reason I haven't implemented this as a standard feature 
is that it might not be reliable.  If you happen to have a K3 with 
better isolation than most, there may not be enough IF leakage to be 
usable.  (I didn't want to volunteer to take the customer service calls. :=)

Another reason is that you can't use it to measure signal quality 
anyway.  It just displays the IF signal before up-conversion and 
amplification, so most signal defects don't show up.

The one thing it is useful for is to adjust the transmit equalizer.  I 
did this on my own K3 to reduce the bass and enhance the treble to get a 
more-or-less flat frequency response with my voice and mic.

If you want to do that, just temporarily disconnect the RS-232 cable 
between the K3 and P3.  That way the P3 doesn't know when the K3 is 
transmitting and so it continues to display the spectrum.  Since 
adjusting the equalizer is generally a one-time "set and forget" 
procedure, I figured it is not too inconvenient to have to unhook the 
RS-232.

Alan N1AL

On 05/19/2015 08:04 AM, giw at bellsouth.net wrote:
> After waiting for 4 years, I was very disappointed  that the new
> monitor in addition to the RF views did not provide a way to look at
> the transmit audio in the pass band  in the same manner as it does
> for received SSB audio. All of the newer Icom Rigs have this
> capability.
>
> On numerous occasions I have briefly seen my own audio show up during
> transmit but as soon as speech is paused, the P3 reverts to receive
> and on transmit the scope freezes.  I have been told this occurs when
> a pin on the RS232 makes and intermittent  poor connection.  The same
> thing can be forced by pulling the RS 232 input to the P3.  I am also
> told that this ability is the result of a “stray” pickup. In my case
> the strength of the stray  pickup, when it occurs, has always been
> enough to provide a good view of my audio if I am running 100 watts.
> By making some pick up changes the strength of this stray signal
> could be increased or amplified.
>
> It would seem very possible to have a menu selection that would allow
> the P3  to break the connection upon transmit to allow you to use the
> display to set up your own audio and to see what is happening at the
> audio level. The P3 now shifts back and forth from receive to
> transmit and instead of freezing the display during transmit,  in a
> new mode it would allow your own audio to display  in the pass band
> instead of the new SSB  view.
>
> It might even be done on a manual basis by having an RS 232 adapter
> in the line that would have a manual switch connected that would open
> and close the line. This would only be used when working with your
> own audio. In this case the new modes would have to be turned off to
> take the P3 back to where it is now.
>
> Any one else have any interest in the above or any experience in this
> area???  Wayne, Eric  or Al any comment please.
> ______________________________________________________________

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