Posted by
Neal Campbell and Sarah Ferrell on
Feb 22, 2005; 1:09am
URL: http://elecraft.85.s1.nabble.com/KSB2-problem-status-befuddled-tp374866p374868.html
Hi all,
Thanks for giving some ideas!
I checked the resistors on the bottom of the ssb board, they are all
correct. I must say that trying to identify parts on the top of the
board is a real challenge, its so stuffed that its almost impossible!
Don, I redid the output amperage at 10 watts:
80 - 2.68
40 - 2.72
30 - 2.28
20 - 1.96
17 - 2.42
15 - 2.50
12 - 2.24
10 - 2.16
At 10 watts on 40, the voltage on rx is 13.5 on tx its 12.9.
The group is right, I did not notice the power output on lower than 17m
(which is 15 watts). On 15 through 10, highest output is 13.3 watts.
Do I still need to investigate the 40m current usage?
Do I need to replace the 3 resistors and jumper that I pulled out to
eliminate the noise blanker module from the mix of things to
investigate? I should have done one module and waited to know it worked
before doing a second one!
Neal
On Feb 21, 2005, at 5:37 PM, W3FPR - Don Wilhelm wrote:
> Neal,
>
> There may be nothing wrong with 40 meters after all - I had missed the
> point
> that you were setting the Power control to absolute max. What is your
> power
> supply voltage? 13.8 volts is typical (13.6 on the display), and lower
> power supply voltages will result in increased current draw. What is
> the
> voltage when you are seeing a current of 3 amps or greater?
>
> I don't have a straightforward answer here. Can it be that your
> Carrier
> Balance is not correctly set and you are really generating more RF
> drive
> with SSB than with CW?
>
> It is not really a fair comparison to compare current draw from band
> to band
> with the Power control set all the way clockwise. Set it to 10 watts
> and
> check the current drawn for each band and both CW and SSB modes.
> Actually SSB mode should draw little current without audio if the
> carrier is
> balanced because there should be little or no RF output.
>
> 73,
> Don W3FPR
>
>> -----Original Message-----
>> Hi Don and all,
>>
>> I have spent the afternoon looking for where I could have made a
>> mistake on the 40m LPF circuit. I didn't find any obvious ones, the
>> toroids came from 'The guy de Toroids' but I counted them all anyway,
>> and they are (luckily!) correct. Same for capacitors. Did the run of
>> voltage checks and didn't notice anything really wrong.
>>
>> On cw, cranking the output knob to the max, the display readings for
>> current are
>> 80 3.22
>> 40 3.36
>> 30 2.84
>> 20 2.38
>> 17 3.08
>> 15 2.84
>> 12 2.62
>> 10 2.42
>>
>> Output reads over 15 watts in all cases, usually abt 15.2. This reads
>> pretty much the same with or without the SSB module installed.
>>
>> I take it from your comments that the fact that 40m is the highest cw
>> reading, its indicative of something wrong. Looked at LPF and BPF
>> areas. What should I expect on the amp readings, 2.35 on 40 and a
>> gradual increase as I go towards 10m?
>>
>> I could reinstall the resistors and jumper and take out the noise
>> blanker module as thats something put in yesterday, I take it that I
>> need to do that if I want to test without it?
>>
>> I have boosted cal cur to 4.0 and still can get hi cur signal with
>> output fully counterclockwise on both usb and lsb. I have been very
>> happy working cw all week as it is (set the cal cur to 3.5 and it
>> hasn't tripped yet).
>>
>> Any more ideas to look at?
>>
>>
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>
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