Thanks Don and others for the answers.
In my case, I'm trying to run down a proble where the KPA100 will be
fine, then all of a sudden it's output will jump up over 140W. I
thought that the high output in the base K2 might be the cause. So are
we saying that some variation is ok, and once in a while if the KPA100
gets up over 150W then we're ok? This is not apparently an oscillation
issue, as I don't see high SWRs.
Thanks,
Jeff
On 4/23/07, Don Wilhelm <[EMAIL PROTECTED]> wrote:
Jeff,
That is normal behavior - the power will climb a bit if left in TUNE for
a period of time. It is mostly the result of heating in the PA
transistors. In normal operation, either with CW or SSB, there is not a
constant carrier being transmitted and the same conditions will not be
present.
Do not leave the K2 in TUNE at high power for any significant length of
time - remember that TUNE is transmitting at a 100% duty cycle. OK for
short bursts, but not good for longer periods. The base K2 shoud be
limited to 5 watts or less for a 100% duty cycle transmission and to 35
watts or less with the KPA100.
73,
Don W3FPR
Jeff Kinzli N6GQ wrote:
> Hi Don,
>
> Thanks for the replies.
>
> To answer your questions, the problem occurs into a dummy load.
>
> I set the base K2 (without KPA100 connected) to 5.0W, and then TUNE,
> and it starts at 5.0W and heads upwards to 5.7-6.0W (read from the
> display, as well as the S-meter). After about 10 seconds in TUNE, it's
> up to 5.7 or 6W and the next LED on the S-meter is starting to flicker
> some.
>
> Moving the power knob will allow me to bring it back to 5.0W, but the
> next TUNE will see the power climb back up again.
>
> I'm not sure if I should still be looking on the RF board at this
> point, or start focusing on the control board...?
>
> Thanks, 73,
>
> Jeff
>
> On 4/22/07, Don Wilhelm <[EMAIL PROTECTED]> wrote:
>> Jeff,
>>
>> Another thought and a question - does the K2 control power properly
>> (check with TUNE) when the requested power is set to 5 watts? If you
>> get somewhere between 4.5 and 5.5 watts output with the requested power
>> set to 5, then the power control circuits are working as they should be.
>>
>> Setting the power to maximum will not readily reveal any problems with
>> the power control.
>>
>> OTOH, if the power output is always high then you do have a problem in
>> the power control (ALC) loop.
>>
>> 73,
>> Don W3FPR
>>
>> Jeff Kinzli N6GQ wrote:
>> > Don and others,
>> >
>> > A few weeks back, a user posted about an issue with low power output
>> > with his K2. Don said:
>> >
>> >> If you do not have either the KAT2, the KPA100, or the KAT100
>> >> installed, the
>> >> K2 does not display the actual power output on the LCD (the requested
>> >> power
>> >> is displayed briefly when the power control is changed). What is the
>> >> indication on the LED bargraph during transmit?
>> >
>> > I'm going through an issue with my K2 where it *appears* to be putting
>> > out too much power. With the KPA100 installed, the output sometimes
>> > jumps up to 150+W.
>> >
>> > I removed the KPA100 from the picture and have been seeing if I can
>> > reproduce higher than normal output with just the base K2. So far, the
>> > behavior is that if I enter TUNE mode, the indicated power on the
>> > display of the K2 will rise to 16-17W. My watt meter isn't accurate
>> > enough to tell me what it's *really* putting out though, although with
>> > the KPA100 it is accurate enough to see the 150W+ peaks.
>> >
>> > So I was trying to think if it's really putting out 16+W, or if the
>> > power meter is really telling me it's TRYING to put it out (because my
>> > external wattmeter looks like actually less, but again not accurate).
>> >
>> > I also thought maybe it's an ALC issue, because if I rotate the power
>> > knob back then back up to max, the indicated power on the K2 will go
>> > to about 15W, but the next time I do TUNE again, it again goes back up
>> > to 16+W.
>> >
>> > Any thoughts on this? Should I keep chasing ALC issues? I've already
>> > gone through the base K2 RF board resoldering T1-T4, reheating
>> > anything that looks suspect, etc. to no avail.
>> >
>> > I also sent something to this effect to [EMAIL PROTECTED], I'm just hoping
>> > someone might have any ideas that I could chase down.
>> >
>> > Thanks,
>> >
>> > Jeff
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