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HI CUR and 160 Meters

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John Huffman-2

HI CUR and 160 Meters

While waiting for parts to fix my KPA100 and KAT100, I was checking out
my K160RX.

The situation is that at 12W out the K2 (KSB2, KNB2, KDSP2, K106RX,
KIO2) draws 2.5 amps. With power set at anything above that, it exceeds
4.5 amps and I get a Hi CUR warning (limit set at 4.5 amps).

Current is a bit higher than expected on 80 meters at 3.2 amps max
output. Other bands 2.9 - 2.9 amps.

I wonder what would cause the jump?

73 de K1ESE
John
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k6dgw

Re: HI CUR and 160 Meters

John Huffman wrote:
> The situation is that at 12W out the K2 (KSB2, KNB2, KDSP2, K106RX,
> KIO2) draws 2.5 amps. With power set at anything above that, it exceeds
> 4.5 amps and I get a Hi CUR warning (limit set at 4.5 amps).

Parasitic? I had that problem on 40m with the KPA100 and KAT100. Ran
OK at lower power (~15W - 25W) but went berserk at higher power. It
even blew the 12V DC line fuse once. Gary fixed it but I'm not sure
what he did.

Fred K6DGW
Auburn CA CM98lw
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Petr Ouředník

Re: HI CUR and 160 Meters

Hi,

I have the same pb on 160m only. Below 6W out is OK, but when trying higher power than 6W then ramp up the current and HiCur warning comes althought the SWR indicated after tunning by ATU is 1.2...K2 not K2/100.
73, Petr OK1RP

> ------------ Původní zpráva ------------
> Od: Fred Jensen <[hidden email]>
> Předmět: Re: [Elecraft] HI CUR and 160 Meters
> Datum: 22.11.2006 23:55:53
> ----------------------------------------
> John Huffman wrote:
> > The situation is that at 12W out the K2 (KSB2, KNB2, KDSP2, K106RX,
> > KIO2) draws 2.5 amps. With power set at anything above that, it exceeds
> > 4.5 amps and I get a Hi CUR warning (limit set at 4.5 amps).
>
> Parasitic? I had that problem on 40m with the KPA100 and KAT100. Ran
> OK at lower power (~15W - 25W) but went berserk at higher power. It
> even blew the 12V DC line fuse once. Gary fixed it but I'm not sure
> what he did.
>
> Fred K6DGW
> Auburn CA CM98lw
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
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>
>
>

Petr Ouředník
00420608230010 (private)
[hidden email]
http://ok1rp.blog.cz (Hamradio)
http://topband.blog.cz (160m)
www.qsl.net/ok1rp
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Tom Hammond-3

Re: HI CUR and 160 Meters

In reply to this post by k6dgw

Different problem when he doesn't have a KPA100 though.

Tom

At 04:53 PM 11/22/2006, Fred Jensen wrote:

>John Huffman wrote:
>>The situation is that at 12W out the K2 (KSB2, KNB2, KDSP2, K106RX,
>>KIO2) draws 2.5 amps. With power set at anything above that, it
>>exceeds 4.5 amps and I get a Hi CUR warning (limit set at 4.5 amps).
>
>Parasitic? I had that problem on 40m with the KPA100 and
>KAT100. Ran OK at lower power (~15W - 25W) but went berserk at
>higher power. It even blew the 12V DC line fuse once. Gary fixed
>it but I'm not sure what he did.
>
>Fred K6DGW
>Auburn CA CM98lw
>_______________________________________________
>Elecraft mailing list
>Post to: [hidden email]
>You must be a subscriber to post to the list.
>Subscriber Info (Addr. Change, sub, unsub etc.):
>http://mailman.qth.net/mailman/listinfo/elecraft
>
>Help: http://mailman.qth.net/subscribers.htm
>Elecraft web page: http://www.elecraft.com

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Don Wilhelm-3

RE: HI CUR and 160 Meters

In reply to this post by John Huffman-2

John,

How much power is actually being produced? What does the K2 meter indicate
in TUNE?
What is your power supply voltage under this 4.5 amp load? If the voltage
drops significantly, the current will go up - the K2 tries to provide the
requested power out, and if the voltage drops, the current must increase.

If you can eliminate power supply voltage drop problems, then you could have
some sort of oscillation present. The K2 is quite stable if all the
components are correct. You could start by checking T1, T2 and T4
(especially T4). The only other thing that I can think of right now are the
components in the base circuit of Q7 and Q8, but I cannot relate to a jump
in current draw if those components were at fault.

Check th evoltage on the base of Q7 and Q8 when transmitting - it should be
0.6 volts or very close.

73,
Don W3FPR

> -----Original Message-----
>
> While waiting for parts to fix my KPA100 and KAT100, I was checking out
> my K160RX.
>
> The situation is that at 12W out the K2 (KSB2, KNB2, KDSP2, K106RX,
> KIO2) draws 2.5 amps. With power set at anything above that, it exceeds
> 4.5 amps and I get a Hi CUR warning (limit set at 4.5 amps).
>
> Current is a bit higher than expected on 80 meters at 3.2 amps max
> output. Other bands 2.9 - 2.9 amps.
>
> I wonder what would cause the jump?
>
> 73 de K1ESE
> John
>

John Huffman-2

Re: HI CUR and 160 Meters

Don -

Yup, looks like a power supply issue.

K2 Meter V I
Receive 13.7 0.34
12 watts 12.6 2.78
13 watts 11.8 4.38
14+ watts 11.3 5.10

Making up a heftier cord to the power supply should do the trick.

Many thanks!

73 de K1ESE
John

Don Wilhelm wrote:

> John,
>
> How much power is actually being produced? What does the K2 meter indicate
> in TUNE?
> What is your power supply voltage under this 4.5 amp load? If the voltage
> drops significantly, the current will go up - the K2 tries to provide the
> requested power out, and if the voltage drops, the current must increase.
>
> If you can eliminate power supply voltage drop problems, then you could have
> some sort of oscillation present. The K2 is quite stable if all the
> components are correct. You could start by checking T1, T2 and T4
> (especially T4). The only other thing that I can think of right now are the
> components in the base circuit of Q7 and Q8, but I cannot relate to a jump
> in current draw if those components were at fault.
>
> Check th evoltage on the base of Q7 and Q8 when transmitting - it should be
> 0.6 volts or very close.
>
> 73,
> Don W3FPR
>
>> -----Original Message-----
>>
>> While waiting for parts to fix my KPA100 and KAT100, I was checking out
>> my K160RX.
>>
>> The situation is that at 12W out the K2 (KSB2, KNB2, KDSP2, K106RX,
>> KIO2) draws 2.5 amps. With power set at anything above that, it exceeds
>> 4.5 amps and I get a Hi CUR warning (limit set at 4.5 amps).
>>
>> Current is a bit higher than expected on 80 meters at 3.2 amps max
>> output. Other bands 2.9 - 2.9 amps.
>>
>> I wonder what would cause the jump?
>>
>> 73 de K1ESE
>> John
>>
>
>