Re: RE: K2 4039,

[JEAN-FRANCOIS MENARD-2]

It seems you have a soldered joint that touch to ground between T2 and
the PA Q7,Q8 or between Q11 or Q13. Check with a magnifier glass around
there. Sometimes you found a soldered joint touch (microscopic lead) to
another part, and that's it.... grounded !!!

Look near all places in this area that parts that should be to ground,
if you do not put too much solder and grounded another part that must
no be to ground.

Seems to me that a defective part should not do what you say, like a
reset when you set higher power. So it must be a bad solder.... I hope
for you.


Le 04-07-10, à 11:26, Nicolas Pike a écrit :

> Hi,
>
> B C E
> Q6 1.04 13.5 .28
> Q7 0 13.5 0
> Q8 0 13.5 0
>
> This is at .2 of a watt, any higher and the radio resets...
>
> Thanks!!!!
>
> Regards
> Nicolas
>
> Previous email for reference
> ----- Original Message -----
> From: Nicolas Pike
> To: [hidden email]
> Sent: Friday, July 09, 2004 6:40 PM
> Subject: [Elecraft] RE: K2 4039, Failing transmitter tests
>
> Hi,
>
> I have steadily and carefully built my K2 and it has passed all the
> tests so
> far with flying colours, including 40m RX. Now I have just completed
> the
> transmitter stages, and attempted the first tx test... Ah problems.
> Well
> things have gone well so far!! Even a bottle of Hoegaarden did not
> help...
> This is what happens.
>
> 1.40m rx working fine.
> 2. Connect dummy load etc
> 3. Set for 2.0 output, tune to 7100
> 4. Press and hold tune.
>
> A bleep in the headphones, the output limiter on the PSU flicks in
> cutting
> the power briefly and Elecraft displays on the K2. (I have tried
> another PSU
> (3amp) but the same result)  If the power is turned down to .2 or so
> it will
> stay in tune mode
>
> Upon checking the antenna connection, there appears to be a short
> between
> earth and the centre of the BNC.. (Using a DVM) This cannot be correct?
>
> I have tried another PSU (3amp) but the same result.
>
> Perhaps you could confirm if an indicated short across the BNC, is
> incorrect, and any suggestions of where to look first would be very
> helpful.
>
> Thanks!!!!!
>
> Regards
> Nicolas
> www.m1hog.com
>
>
>
> -----Original Message-----
> From: JEAN-FRANCOIS MENARD [mailto:[hidden email]]
> Sent: 10 July 2004 15:34
> To: [hidden email]
> Subject: Re: [Elecraft] RE: K2 4039,
>
> What is the vDC you get on C,B and E on Q6, Q7 and Q8 when TX (hold
> tune at 2W to check) ?
>
> Le 04-07-10, à 10:26, Nicolas Pike a écrit :
>
>> Hi,
>>
>> Thanks everyone for the suggestions. I now have some more information
>> to go
>> on!
>>
>> Q7    Collector       3k              OK!
>> Q6    Base            118Ohm  OK!
>> Q7    Base            SHORT           Not OK!!!
>>
>> I have checked the diodes, toroids T1 - T4, and carefully looked over
>> the
>> board for shorts. I have referred to the circuit diagram but I do not
>> really
>> know now to determine if the PA Bias section is grounding it, or if
>> the PA
>> section is grounding itself, or some other section is grounding them!!
>> (Although don't "think" much else can?)
>>
>> Wondered if you had any suggestions?
>>
>> Thanks
>> Nicolas
>> www.m1hog.com
>>
>>
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> ===============================================
> Jean-François Ménard / VA2VYZ
> [hidden email]
>
> Club d'Astronomie Amateur de Sherbrooke
> Club Radio Amateur de l'Estrie
>
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===============================================
Jean-François Ménard / VA2VYZ
[hidden email]

Club d'Astronomie Amateur de Sherbrooke
Club Radio Amateur de l'Estrie

Mon site web personnel : http://homepage.mac.com/jfmenard
===============================================

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[Don Brown-4]

Hi

Actually the K2 will do this with a very high current. The self resetting fuse will open at high current then when it resets the K2 will re-power up giving the reset indication

Don Brown



  ----- Original Message -----
  From: JEAN-FRANCOIS MENARD<mailto:[hidden email]>
  To: [hidden email]<mailto:[hidden email]>
  Sent: Saturday, July 10, 2004 10:58 AM
  Subject: Re: [Elecraft] RE: K2 4039,


  SNIP

   
  Seems to me that a defective part should not do what you say, like a
  reset when you set higher power. So it must be a bad solder.... I hope
  for you.

  SNIP
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