[Elecraft] Problems on 40M with 100 watt section

[Rich McCabe]

Well as it turns out, my current draw is high. About 2.48 according to the 
K2 display. This was at around 8 watts (2:00 position) on the band I 
checked. But all bands appear to be around that 2.45-2.5 range.

I checked the finals to make sure there is no short to ground and they did 
not. Although there was about 3.5 K resistance on both of them. I assume 
this is normal.

I checked the voltage on the finals during xmit and they were 13.4,  .6  and 
0 as they should be.

Time to search the archives. Any comments would be appreciated.

Rich
kd0zv

----- Original Message ----- 
From: "Ron D'Eau Claire" <rondec at easystreet.com>
To: "'Rich McCabe'" <r.mccabe at 1967z28.com>
Sent: Saturday, March 18, 2006 5:49 PM
Subject: RE: [Elecraft] Problems on 40M with 100 watt section


Yeah, you definitely have a problem "farther up the line" from the KPA100.
You should see 10 watts, minimum, on all bands from the basic K2. I'd start
by physically removing the KPA100 and testing again.

In addition to feeding power from only the coaxial plug, you can disable
your KPA100 by going into the secondary MENU commands. Also, it does not
kick in until you set the POWER control at 10 watts or above even with the
high-current supply enabled. You can hear a relay click when the KPA100 is
switched in.

But you've determined that the problem is not in the KPA100 itself. Not this
problem at least. First you need to make your K2 produce 10 watts or more on
all bands without it. Ten meters is usually the lowest output band with some
K2's barely making 10 watts, but on other bands, especially 40, most K2's
will produce closer to 15 watts at full power.

Do you hear relays switch when you change bands?? One thing that causes
frequency-specific issues in K2's is if something is amiss in the circuits
that switch in the correct output filter for each band.

Ron AC7AC

-----Original Message-----
From: Rich McCabe [mailto:r.mccabe at 1967z28.com]
Sent: Saturday, March 18, 2006 3:23 PM
To: Ron D'Eau Claire
Subject: Re: [Elecraft] Problems on 40M with 100 watt section


Ron and Tom,

Tom, yes have a scope and can resport to that if needed. Not an expert with
it, but can make it work :)

Ron, I tried doing the low power thing as you suggested by removing power
from the 100watt unit and using the small Power cord.

160 was 9 watts, 40 was 6 watts. The rest of the band went into HI CUR as I
rotated the dial up to about 1 or 2 oclock and got to 7 or 8 watts.  So the
"problem" is further up the line than I thought.


73,

Rich
kd0zv

----- Original Message ----- 
From: "Ron D'Eau Claire" <rondec at easystreet.com>
To: "'Rich McCabe'" <r.mccabe at 1967z28.com>; <elecraft at mailman.qth.net>
Sent: Saturday, March 18, 2006 5:01 PM
Subject: RE: [Elecraft] Problems on 40M with 100 watt section


You should see 100 watts on ALL bands so, yes, those are down. Are you
making a minimum of 10 watts out on all bands with the KPA100 disabled?

I don't have a KAT100 myself, so I won't speculate on what might have caused
your original issue beyond the obvious observation that, apparently, it
wasn't really out of the circuit in some way. It may not have been tuning,
but clearly there wasn't a 50-ohm non-reactive path through it either.

Ron AC7AC

-----Original Message-----

Ron,

This was into a dummy load.

I had it into the KAT100 which was disabled and unplugged. So only the
feedline was left connected though the ATU. Once I removed the KAT100 it
worked.

With the AT removed I did check power output into a dummy load and got the
following

160- 131 watts
75- 118 watts
40- 119 watts
20- 54 watts
17- 55 watts
15 -98 watts
12 - 78 watts
10- 99 watts.

So 20 and 17 are down and 12 slightly??

So I am thinking it must be ATU related and not the 100watt amp section.

Thanks

Rich
kd0zv