KX3 Reduced output power on 20M and above

[dixonsfamily]

I just tried to tune up my L4-B on 17M using the KX3 as the driver. I
noticed the power output was less than the nominal 200 watts that I have
been getting. I checked the output power of the KX3 and it too was down,
about 7.5 watts. I checked to make sure it was matched with the ATU
and  that checked OK. I checked to see what power level it was set to and
that was 10 watts.
 Next, I tried bypassing the amp and tuning into a dummy load. Below 20M it
will put out 10 watts full power. Above it is less than full and output
power decreases as I go to higher frequency bands, i.e. 15,12,10,and
finally 6 with the lowest power out at 3.2 watts into a dummy load.

I checked the voltage reading on the KX3 and it only dropped 0.3 volts from
13.5 to 13.2 volts.

I am sure I had full power into the L4-B last night on 20M.

Does anybody have any ideas as to what may be the problem?

Denis WA5TYJ KX3# 452
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[kd7gc]

Is the SWR on the antenna flat?  It may be higher than the dummy load.  Best to check.

 

 

Alan R. Downing

Phoenix, AZ

 

From: dixonsfamily [via Elecraft] [mailto:[hidden email]]
Sent: Tuesday, September 03, 2013 7:38 AM
To: kd7gc
Subject: KX3 Reduced output power on 20M and above

 

I just tried to tune up my L4-B on 17M using the KX3 as the driver. I
noticed the power output was less than the nominal 200 watts that I have
been getting. I checked the output power of the KX3 and it too was down,
about 7.5 watts. I checked to make sure it was matched with the ATU
and  that checked OK. I checked to see what power level it was set to and
that was 10 watts.
 Next, I tried bypassing the amp and tuning into a dummy load. Below 20M it
will put out 10 watts full power. Above it is less than full and output
power decreases as I go to higher frequency bands, i.e. 15,12,10,and
finally 6 with the lowest power out at 3.2 watts into a dummy load.

I checked the voltage reading on the KX3 and it only dropped 0.3 volts from
13.5 to 13.2 volts.

I am sure I had full power into the L4-B last night on 20M.

Does anybody have any ideas as to what may be the problem?

Denis WA5TYJ KX3# 452
______________________________________________________________
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Help: http://mailman.qth.net/mmfaq.htm
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