Don,
I suspected something might be wrong with the watt meter, as it was borrowed
from work and had not been used in a while.
I was able to listen to quite a few signals last night, however I wasn't
able to make any contacts. I brought my radio into work and tested it on a
Rhode and Schwartz
Jeremy,
Strange problem.
The K2 RF power detector consists of voltage divider R67 and R68 and
diode D9. One end of R67 is connected directly to the BNC center
conductor. That means your problem is quite a mystery. Could it be a
bad coax or a faulty (or not soldered) BNC connector. The
So, I have learned another lesson on paying attention to details. Seems the
analog watt meter I was using is only rated as low as 20mhz, and the digital
Rhode and Schwartz actually had a 200Mhz sensor on it. No wonder the
readings were bad.
I did go back to the analog meter on 15M, 12M, and
Jeremy,
A high SWR will cause that behavior.
Make certain the coax you are using is good. Remove it from the K2 end
and check with an antenna analyzer if possible.
If you cannot do that, look at the SWR registered on the wattmeter - if
it is 1:1, remove the wattmeter and connect that coax to
Looks like a bad coax was indeed causing the high current issue. I've
resolved that, but I'm still show no power out on the external watt meter,
while the internal is reading 2.4.
Jeremy
VA3ZTF
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Jeremy,
What range is your external wattmeter set for? If it is 100 watts or
200 watts, you will probably not get any deflection at 2.4 watts.
When the load is 50+j0 ohms, you can rely on the K2 display.
I suggest removing the external wattmeter and using the display.
73,
Don W3FPR
On
The watt meter has a 5, 15, 50, 100W ranges, and I was using the 15 and 5 to
try and get measurements. Carrying on with calibration using the internal
meter yielded the expected results. I may actually be able get this on the
air tonight!
Thanks for the help,
Jeremy
VA3ZTF
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Jeremy and all, the external wattmeter reading has to overcome the
diode drop in the wattmeter before it will provide deflection. At low
power levels it may show no response until the power is great enough for
the diodes to conduct.
The full scale reading of the wattmeter may be correct, but
I'm trying to complete the stage 3 transmitter alignment on my K2 and have
run into a bit of a snag. The 40M check looks good according to the built
in power meter, however with an external watt meter connected to a dummy
load, I am getting less than 1W on the with the K2 set at 2W, and about 2W
Jeremy,
The problem of HiCur coupled with low power output is usually associated
with a problem either in T4 or the Low Pass Filter.
Check all the capacitors in the Low Pass Filter for proper values and
count the turns on the toroids. Count only the turns passing through
the center of the
Hi Don,
The capacitors all look good, and I found one issue with a toroid and
corrected it, but the issue remains. T4 is wound with proper number of
turns, but wires do overlap some instead of being stacked neatly. Not sure
if this could cause an issue or not. T4 is also standing off the board
Jeremy,
T4 being off the board should not make any difference. Are you
operating into a dummy load that is 50 ohms pure resistive, or are you
operating into an antenna? The base K2 needs to operate into a 50 ohm
resistive load for good power control and a proper impedance.
If you are
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