[Elecraft] K2 SSB

[raimon]

Dear Don
I thank you for the information.
Following your advice. I looked first for a bad solder in the KSB2 
module. As no poor solder was apparent, I decided to resolder all 
connections. After this re-work  the failure has been cured. The K27100 
in SSB mode is working again as it had been until recently.
I thought that my soldering skills were good enough, but I was wrong. Hi.
Many thanks for your help ¡¡¡
Best regards, 73
EA3EZO     Raimon

En/na Don Wilhelm ha escrit:
> Raimon,
>
> I do believe your first checks should be on the KSB2 option board.
> Look at the schematic for the KSB2 in the lower left corner area - you 
> will find several passive components associated with Q1, D1 and D2 - 
> those are the components are in the SSB ALC section and are the ones 
> to check.
>
> I would look first for a poor solder connection.  It is not uncommon 
> for a marginal solder connection to fail after a few years even if it 
> worked fine initially - once an oxide coating develops, it will fail 
> (usually because of a higher than normal resistance at the 
> connection).  It *could* be a component failure, but I would check the 
> soldering first and re-flow it if there is any question at all about 
> its current quality.
>
> I tend to believe that the band dependency is a 'red herring' and is 
> the simple result of the fact that the intrinsic transmit chain gain 
> of the K2/100 goes down as the frequency is increased.
>
> If you find no problem obvious on the KSB2 board, I would suggest that 
> you remove the KPA100 and test the base K2 for a similar condition.
>
> 73,
> Don W3FPR
>
> raimon wrote:
>> Hi all
>>
>> I am having troubles with my K2, and need your help
> .................................................
>> Now it continues to work all right in CW in all bands, but in SSB 
>> power output drops substantiably in 20, 30, 15 ,12 and 10 meters bands.
>>
>>
>> I suspect the KSB2SSB module. Where should I look for the cause of 
>> this problem?
>>
>> Many thanks in advance
>>
>> Raimon
>>
>> EA3EZO
>>
>> rfuidio at telefonica.net <mailto:rfuidio at telefonica.net>
>>
>> _______________________________________________
>