Andrew,
If you cannot get at least 10 watts out of the base K2 over all the 160
meter band you have a problem in either the 160/80 meter bandpass filter
or the 160m low pass filter. I encourage you to look there first.
You will likely have to compromise the bandpass filter settings between
160 and 80 meters. Set the filter inductors midway between the peak at
3700 kHz and 1850 kHz for your initial trial and make slight adjustments
from there. Check the coupling inductor to be certin it is the right
value - your report indicates that the bandpass filter may be more
narrow than normal.
That being said, low power combined with high current warnings do
indicate a problem with the low pass filter for that band - be certain
the capacitors are the correct value and the number of turns on the
toroids are correct.
If you had not already discovered, the limited power out of the base K2
is what is likely causing the reduce power from the KPA100.
73,
Don W3FPR
[EMAIL PROTECTED] wrote:
HI,
I have just fitted the DSP board and it works fine, on
putting the K2 back together, I fond that 160M will not go
above 50 Watts and I get a high current warning, All other
bands are 111 Watts no problem. I am using Rohde & Schwarz
power probe and a 40dB attenuator, to the match is close to
50 OHMS. I have also used my bird through line and get the
same results. I suspected the band pass filter in the KPA
100, I did find what looked a poor joint on L1, but re
soldering has not cured the problem. I do not like
disturbing the PCB and power transistor mounts so need to
pinpoint quickly. In QRP mode the K2 works fine. ( 6 Watts
1800 to 2.000 with 11 watts at 1900 I have never had 10
Watts + on this band). I will sweep the low pass filter
tonight, if I find this in order, I will then connect the
Watt meter directly to input to the low pass filter and see
if everything is fine at this point. Has any one had this
before and can give some pointers it would be appreciated?
The SWR circuit gives 1:1 into the dummy load so is metering
correctly. Has anyone know C2A, C2B, C2C, C2C, C2D, or CDE
to fail or indeed L1 and L2
73
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