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K2/100 Power Measurements

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DL9HDA

K2/100 Power Measurements

Hi,

after I finally installed the KAF2 module in my K2/100 05775, it was
time to do a complete alignment and I ran into this old problem again.

The output power at 160 m is 100 W. And drops from band to band to 80 W.

Now I have adjusted the KPA100 to 10m. Now I have there 100 W but then
on 160 m 120 W.

Measured with an LP-100A and dummy load. SWR is fine!

It looks as if the whole power measurement shows a certain skewness.

Any hint?

73s, Holger DL9HDA

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Don Wilhelm

Re: K2/100 Power Measurements

Holger,

Is your power supply voltage at 13.8 volts or better yet 14.3 volts?
That should be as measured by the voltage display on the K2. It should
not drop below 12.7 volts during a 100 watt transmit.

Part of the problem may be attributed to the voltage vs. frequency curve
of KPA100 D16 - which should be a 1N5711 diode. I have seen diodes that
have become "flaky" with use, replacement with a new one is the only
cure should that be the problem.

Other than limited voltage to the KPA100 or the response curve for D16,
there is usually no other answer for the behavior you are seeing.

Remember that the power may vary by as much as 1 dB from band to band,
and at the 100 watt level is about 20 watts, so you may not have any
problem other than diode tolerance vs. frequency.

73,
Don W3FPR

On 11/4/2019 4:53 PM, Holger Doerschel wrote:

> Hi,
>
> after I finally installed the KAF2 module in my K2/100 05775, it was
> time to do a complete alignment and I ran into this old problem again.
>
> The output power at 160 m is 100 W. And drops from band to band to 80 W.
>
> Now I have adjusted the KPA100 to 10m. Now I have there 100 W but then
> on 160 m 120 W.
>
> Measured with an LP-100A and dummy load. SWR is fine!

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DL9HDA

Re: K2/100 Power Measurements

Dear Don,

I read at the K2 13.6 V. It is a Powerwerx PS from Elecraft with the two
Powerpole connectors at the front. The Voltage drops at 100 W / 28 MHz
to 12.2 V. I already replaced D16. No change. I tried several PS.

73,

Holger DL9HDA

On 05.11.19 02:46, Don Wilhelm wrote:

> Holger,
>
> Is your power supply voltage at 13.8 volts or better yet 14.3 volts?
> That should be as measured by the voltage display on the K2. It
> should not drop below 12.7 volts during a 100 watt transmit.
>
> Part of the problem may be attributed to the voltage vs. frequency
> curve of KPA100 D16 - which should be a 1N5711 diode. I have seen
> diodes that have become "flaky" with use, replacement with a new one
> is the only cure should that be the problem.
>
> Other than limited voltage to the KPA100 or the response curve for
> D16, there is usually no other answer for the behavior you are seeing.
>
> Remember that the power may vary by as much as 1 dB from band to band,
> and at the 100 watt level is about 20 watts, so you may not have any
> problem other than diode tolerance vs. frequency.
>
> 73,
> Don W3FPR
>
> On 11/4/2019 4:53 PM, Holger Doerschel wrote:
>> Hi,
>>
>> after I finally installed the KAF2 module in my K2/100 05775, it was
>> time to do a complete alignment and I ran into this old problem again.
>>
>> The output power at 160 m is 100 W. And drops from band to band to 80 W.
>>
>> Now I have adjusted the KPA100 to 10m. Now I have there 100 W but
>> then on 160 m 120 W.
>>
>> Measured with an LP-100A and dummy load. SWR is fine!
>

Jim Brown-10

Re: K2/100 Power Measurements

On 11/4/2019 8:49 PM, Holger Doerschel wrote:
> drops at 100 W / 28 MHz to 12.2 V.

What size wire? How long?

73, Jim K9YC
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EricJ

Re: K2/100 Power Measurements

Guy goes into Home Depot to buy some wire.

"What size wire?"

'Uh, #14, I think."

"How long?"

"Uh...a long time. We're building a house."

Sorry.....Eric KE6US

On 11/4/2019 9:05 PM, Jim Brown wrote:

> On 11/4/2019 8:49 PM, Holger Doerschel wrote:
>> drops at 100 W / 28 MHz to 12.2 V.
>
> What size wire? How long?
>
> 73, Jim K9YC
> ______________________________________________________________
> Elecraft mailing list
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>
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