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Hi Current K2

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richard gilley

Hi Current K2

>
> I am embarrassed to say but I have a high current indication on
> nearly all bands during Tx. (new build and I thought I was being so
> so careful).
>
> The Rec. draws 240 ma. at 12.4 volts. Does change slightly with
> option changes.
>
> Attempted transmitter Tune up Test Part Three page 77 has the
> following results:
>
> 4.045 Mhz - Hi Cur LCD to P19
> 7.099 Mhz - Hi Cur LCD to P19
> 10.00 Mhz - Hi Cur LCD to P18
> 14.060 Mhz Hi Cur LCD to P16
> 18.090 Mhz NO Hi Cur LCD to P.3
> 21.054 MHZ No Hi Cur LCD to P.8
> 25.012 Mhz NO Hi Cur LCD to P.1
>
> Power set to 2W and 1 W with same indication.
>
> Current limit set to 2.5A.
> Voltage on C of Q8 and Q7 at 12.4 Vdc.
> Res, measurements page 74 all within limits.
>
> Changed power supply, when I noticed voltage drop and high current
> reading of 5 A. No change with known good supply.
>
> Hints requested before I tear something.
>
> Best regards
> Dick AD1G
>
>
>

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Don Wilhelm-4

Re: Hi Current K2

First question is - why are you using 4.045 MHz - that is outside the
ham band. Use 3.750 MHz instead. Similarly, 10.00 MHz should be in the
range of 10.100 to 10.150 MHz. Also 25.012 is not a good frequency
either, use 24.90 That is not likely to change your results with the
HI-Cur display, but just a comment.

Your receive current draw is about normal - no problem there.

Set CAL CUR to 3.50 amps and try again with the power set to 5 watts.
If the power goes up to a high value (much above 5 watts), there is a
problem with the power control circuits.

The lack of decent power output on 17 meters and up may be an entirely
different problem. Normally Hi-Cur combined with low power output
indicates a problem in the Low Pass Filter or T4.

Please measure the voltage at the base of Q7 and Q8 during a TUNE. It
should be 0.6 to 0.63 volts.

73,
Don W3FPR

richard gilley wrote:

>
>
>> I am embarrassed to say but I have a high current indication on
>> nearly all bands during Tx. (new build and I thought I was being so
>> so careful).
>>
>> The Rec. draws 240 ma. at 12.4 volts. Does change slightly with
>> option changes.
>>
>> Attempted transmitter Tune up Test Part Three page 77 has the
>> following results:
>>
>> 4.045 Mhz - Hi Cur LCD to P19
>> 7.099 Mhz - Hi Cur LCD to P19
>> 10.00 Mhz - Hi Cur LCD to P18
>> 14.060 Mhz Hi Cur LCD to P16
>> 18.090 Mhz NO Hi Cur LCD to P.3
>> 21.054 MHZ No Hi Cur LCD to P.8
>> 25.012 Mhz NO Hi Cur LCD to P.1
>>
>> Power set to 2W and 1 W with same indication.
>>
>> Current limit set to 2.5A.
>> Voltage on C of Q8 and Q7 at 12.4 Vdc.
>> Res, measurements page 74 all within limits.
>>
>> Changed power supply, when I noticed voltage drop and high current
>> reading of 5 A. No change with known good supply.
>>
>> Hints requested before I tear something.
>>
>> Best regards
>> Dick AD1G
>>
>>
>>
>>
>
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