[Elecraft] Inconsistant drive with SSB

[Ron D'Eau Claire]

> I have noticed something for a while with my K2.  I can get 10w+ on all
> bands in CW mode.  When I switch to SSB, the amount of tx audio required
> varies GREATLY from band to band to achieve 10w peak.
>
> I will be doing some experiments tonight to try to determine a cause.  Has
> anyone else noticed this with their K2+KSB2?
>
> 73 de John - KC4KGU
> K2 #2490


Yes. That is NORMAL behavior. The total gain of the transmitter r-f
amplifier chain varies widely from 160 or 80 meters to 10 meters. Usually
the gain is lowest at 10 meters, which is why that band usually shows the
lowest "maximum" r-f output at "full power" setting.

The ALC in the K2 works by adjusting the audio level to produce the
requested power output, so it will require different levels of audio
depending upon the band. You can see this by watching the ALC function
(press & hold RF/ALC) on the bargraph. On bands where the r-f gain is
highest through the transmitter circuits, you will have maximum ALC action.
40 meters will usually show two or even three bars of ALC on voice peaks. 10
meters, on the other hand, often barely flashes one bar.

You should be able to get 10 watts, peak, on any band. The bargraph shows
"peak" r-f output on SSB. Keep in mind that 10 watts peak is all the power
Elecraft recommends to avoid excessive IMD on your signal even though you
may be able to get a few more watts out on some bands. .

Ron AC7AC
K2 # 1289