[Elecraft] K2 - No SSB Output (long)

[Ron D'Eau Claire]

Hi Colin:

The first test of SSB output is to hook up a dummy load to the K2 and
look at the RF output indication on the bar graph rather than your
external meter. Most external watt meters are the "averaging" type. The
internal K2 circuit is a "peak reading" meter. Set your POWER control to
10 and be sure your menu setting for SSBA is "2" (gives you full gain
from the mic).  Transmit and watch the K2 bargraph while talking into
the mic. It should flicker across, just hitting 10 on some voice peaks.
Most of the time the audio will bounce between 5 and 7 on the bargraph
scale (with the compression off - SSbC 1-1).=20

If it hits 10, you are getting all the RF out the K2 is capable of
generating. The only way to increase your talk power now is to add
compression (SSbC 2-1 to 4-1) or add an amplifier or a better antenna.
Keep in mind that a signal that is very loud in CW can be "barely
audible" in SSB. That's because of the difference in bandwidth between a
CW and SSB signal. Your RF is concentrated in a bandwidth of about 50 Hz
(depending upon your keying speed) in CW and it is spread out over 2000
Hz on SSB.=20

Check the output on various bands. If you are going to have low output
on any band  (assuming your K2 can make at least 10 watts CW on all
bands) most likely it will be on 10 meters. The gain of the RF strip in
the K2 transmitter is lowest on this band, so it requires the most drive
from the audio circuits.

If you like, you can now add your external wattmeter and see what it
does. It will likely wiggle very LOW on the scale. The Human voice has a
very low average-to-peak power ratio, and your averaging wattmeter will
show this. That's why compression is so popular in SSB rigs. It kills
the "natural" sound of the voice, but it really brings up the "talk
power" by reducing the amplitude of the voice peaks thereby bringing up
the "average" power quite a bit.=20

If your output is low as shown on the K2 bargraph, first check your mic
connections. Be sure you have voltage getting to the electret element of
the mic.=20

Ron AC7AC
K2 # 1289


Yeah, K2 #2833 is fully functional, well almost.  ....
 =20
When I switch to either of the SSB TX modes I get very little, or no,
deflection on my antenna tuner's watt meter. I have checked with a
fellow ham a few miles away and he indicates that my SSB TX signal is
barely audible. It works great on CW and seems to work well on SSB RX.
I've listed some test data below.
  ......
Cheers,
Colin
N=D8YGY