[Elecraft] K3 Observations Digital Modes and SSB

[Kok Chen]

On Feb 2, 2011, at 2/2    11:14 AM, goldtr8 at charter.net wrote:

> Thanks that now makes sense to me.  However, than almost every signal
> that I am looking at is outside of the two main carriers.  Like little
> spikes, I don't know how else to define it.

You only see two clean rails (plus IMD rails) when the PSK31 signal is  
idling.

When someone types, their PSK31 signal will produce other sidebands --  
so you see that fuzzy signal on a waterfall.

With enough trickery, you can measure 3rd order IMD even when a  
station is actively transmitting.  But the best time to measure is  
when a station is idling.

> The IMD Meter you mention looks like a good investment.

An even better investment is the Elecraft Directional Coupler.  You  
can then tap the output from the K3 and feed that into a second  
receiver that has a computer connected to the second receiver's sound  
card.

Measuring IMD is not so good if you just use a short sense antenna.  
Best to tap off of a directional coupler.

73
Chen, W7AY