[Elecraft] [K2] Safely running 100% key-down modes

[EricJ]

I run JT9 and JT65 very frequently with the K2/100. Most of the time, I 
run 5 watts. If needed I'll crank it up to 20 watts, so I can assure you 
it's quite safe at that power level.

When the linear kicks in the K2 drive power to the linearis 
proportional, so if you are within the duty cycle of the linear, you are 
within the duty cycle of the K2 barefoot.

At 20 watts the fan usually comes on after about 30 seconds of TX and 
stays on for the remainder of the TX cycle and much of the RX cycle. At 
around 25-30 watts, the fan is on all the time, but I don't ever run it 
that high. The JT modes are meant for weak signals so I only work weak 
signals and find that at 15-20 watts I'm giving very close to the same 
signal report I receive.

For PSK, I stick to the same power levels as JT modes.  I don't run PSK 
very often because it's not as interesting to me. I lost patience with 
brag tapes in the RTTY days. Now they provide model numbers of every 
rig, every radio accessory and every computer specification including 
version numbers of software even if they aren't using that gear for the 
QSO. Sort of a shopping list for burglars.

The K2 does a very nice job with all the digital modes.

Eric
KE6US



On 12/26/2013 9:06 AM, K1FFX wrote:
> I starting to use my K2/100 in two 100% key-down modes, JT-65 and PSK-31.
> What
> should I be keeping in mind in protecting the output stage for the K2 and
> for the KPA100?
>
> For JT-65, since it is a QRP mode, I'm running at about 5 watts, and
> transmissions are
> limited to about 45 seconds.  So, I'm hoping that K2's output transistors
> will not be stressed
> in this mode.
>
> But, how about PSK-31?  I'd like to run about 20 watts and each transmission
> could easily
> be 3 or so minutes.  I don't know at what output power the base K2 runs when
> the KPA100
> kicks in (i.e., at above 10 watts).  I assume that normally the KPA100 will
> be loafing at 20
> watts, but I'm not sure the impact of 100% key down on its output stage.
>
> I'd appreciate any guidance in keeping the K2/100 "safe" in these modes.
>
> Thanks -
>
> Bruce K1FFX
>
>
>
>
> -----
> Bruce Rosen
> K1FFX
> K2/100 6982 KSB2 KAT100-1
>
> --
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