K2+KPA100 hi current and hi output

[Andre]

Dear All,

I gave a new home to a  K2 + (KPA100+KAT100 in EC 2), ser#>5000. The K2
on its own is runnung fine.

When I connect to the KPA+KAT I get HiCur warning (on initiating TX) on
all bands with POW>10W. This also happens when I transmit into a dummy
load. I measured the output from the dummyload with a DMM. There are
only two values (depending on the dialled in watts):

Below 10W = 38 VDC (= 14W)
Above (I checked 20, 50, 80, 100W) = 129 VDC (= 160W!!)

In other words, as soon as the KPA is activated, the output is 160W
(according to my formula for converting VDC in W). The meter on the
power supply (good for 25A) confirms that I draw about 20A above 10W in,
apparently only limited by the slow 20A fuse in the line.

Any ideas as to what may be wrong and where I should start?

Many thanks in advance for your help!

73 de andre dm1aa
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[K1FFX]

Hi, Andre -

I wonder if it's a problem with blown D16 and D17 in the KPA100.

If you follow this forum on-line at nabble.com, you can do a search for
"D16" and
see many postings on the topic.

Good luck.

- Bruce K1FFX




-----
Bruce Rosen
K1FFX
K2/100 6982 KSB2 KAT100-1 KAF2 KIO2

--
Sent from: http://elecraft.365791.n2.nabble.com/
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[Don Wilhelm]

Andre,

Do you have any power control?  To check set the power to about 50 watts
and do a TUNE.  Measure the actual power output with an in-line
wattmeter and a 50 ohm dummy load.

If it still goes to 160 watts, you do not have any power control.  The
usual reason is the diodes D16 and D17 (1N5711 type) have been damaged
by static coming in on the feedline.  Replace those diodes and re-check.

If that does not fix it, I can help with additional troubleshooting.

73,
Don W3FPR

On 9/4/2020 4:39 PM, atfu wrote:

> Dear All,
>
> I gave a new home to a  K2 + (KPA100+KAT100 in EC 2), ser#>5000. The K2
> on its own is runnung fine.
>
> When I connect to the KPA+KAT I get HiCur warning (on initiating TX) on
> all bands with POW>10W. This also happens when I transmit into a dummy
> load. I measured the output from the dummyload with a DMM. There are
> only two values (depending on the dialled in watts):
>
> Below 10W = 38 VDC (= 14W)
> Above (I checked 20, 50, 80, 100W) = 129 VDC (= 160W!!)
>
> In other words, as soon as the KPA is activated, the output is 160W
> (according to my formula for converting VDC in W). The meter on the
> power supply (good for 25A) confirms that I draw about 20A above 10W in,
> apparently only limited by the slow 20A fuse in the line.
>

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