Made my first contacts on my K2

[Matthew Denson]

Hi All,

Building the K2 was a lot of fun, and now my basic K2 (#6210) is on the air.  I've made contacts with OR and MI from my location here in CA.  Been able to answer CQs on the first try both times.  Really lovely.

I do have one thing that is nagging at me.  The audio level seems low.  When I first turn on the rig the level seems right.  I have to turn the AF Gain down to be comfortable.  But after a few minutes (8-10) the audio level drops all at once.  It is still usable but it can't be right.

I am going to build the crystal oscillator to do some signal tracing, but wanted to ask if there was a particular place I should look?  I have very little experience with this so use small words. hi hi!

73 de AE6UP Matthew




       
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[Don Wilhelm-4]

Matthew,

Those symptoms are classic for behavior of an unsoldered or poorly
soldered conection.  The connection changes to a poor connection when it
is warmed slightly.

You may be able to narrow it down by tapping on some of the components.

Take a look at the S-meter while receiving a steady signal (WWV may be a
good choice) to see whether there is a change in the S-meter response
when the audio volume decreases.  If it does, the problem is in the
early stages of the receiver (IF amplifier and toward the antenna), but
if the S-meter does not drop, the problem is at the product detector or
other stages toward the audio section.
It also could be the AGC itself that is causing the problem.  Again, the
S-meter is an indicator - if the S-meter increases when the audio drops,
then the problem is with the AGC.

If you find problems with the AGC or the audio itself, check the control
board, and perhaps even reflow the soldering with an iron temperature of
700 to 750 degrees.
If the problem is with the front end of the receiver (antenna to IF
amplifier), then look carefully at the RF board.

Sorry, but in cases like this, I cannot be more specific until you can
provide more data.

73,
Don W3FPR

Matthew Denson wrote:
> Hi All,
>
> Building the K2 was a lot of fun, and now my basic K2 (#6210) is on the air.  I've made contacts with OR and MI from my location here in CA.  Been able to answer CQs on the first try both times.  Really lovely.
>
> I do have one thing that is nagging at me.  The audio level seems low.  When I first turn on the rig the level seems right.  I have to turn the AF Gain down to be comfortable.  But after a few minutes (8-10) the audio level drops all at once.  It is still usable but it can't be right.
>
> I am going to build the crystal oscillator to do some signal tracing, but wanted to ask if there was a particular place I should look?  I have very little experience with this so use small words. hi hi!
>
>  
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[Matthew Denson]

Thank you very much Don.

I found exactly what you indicated.  On side of one of the filter option jumpers was basically unsoldered.  I'll tell you, I took a lot of will power to keep from reheating every joint.  "If I missed that one in my inspections ...."

Tracing it down wasn't actually too bad once I checked the S-meter as Don suggests below.

Well, all is good in K2 land.  I now have audio to spare.  



Thanks and see you all on the air.

73, Matthew AE6UP

----- Original Message ----
From: Don Wilhelm <[hidden email]>
To: Matthew Denson <[hidden email]>
Cc: [hidden email]
Sent: Monday, August 20, 2007 3:12:00 PM
Subject: Re: [Elecraft] Made my first contacts on my K2

Matthew,

Those symptoms are classic for behavior of an unsoldered or poorly
soldered conection.  The connection changes to a poor connection when it
is warmed slightly.

You may be able to narrow it down by tapping on some of the components.

Take a look at the S-meter while receiving a steady signal (WWV may be a
good choice) to see whether there is a change in the S-meter response
when the audio volume decreases.  If it does, the problem is in the
early stages of the receiver (IF amplifier and toward the antenna), but
if the S-meter does not drop, the problem is at the product detector or
other stages toward the audio section.
It also could be the AGC itself that is causing the problem.  Again, the
S-meter is an indicator - if the S-meter increases when the audio drops,
then the problem is with the AGC.

If you find problems with the AGC or the audio itself, check the control
board, and perhaps even reflow the soldering with an iron temperature of
700 to 750 degrees.
If the problem is with the front end of the receiver (antenna to IF
amplifier), then look carefully at the RF board.

Sorry, but in cases like this, I cannot be more specific until you can
provide more data.

73,
Don W3FPR

Matthew Denson wrote:
> Hi All,
>
> Building the K2 was a lot of fun, and now my basic K2 (#6210) is on the air.  I've made contacts with OR and MI from my location here in CA.  Been able to answer CQs on the first try both times.  Really lovely.
>
> I do have one thing that is nagging at me.  The audio level seems low.  When I first turn on the rig the level seems right.  I have to turn the AF Gain down to be comfortable.  But after a few minutes (8-10) the audio level drops all at once.  It is still usable but it can't be right.
>
> I am going to build the crystal oscillator to do some signal tracing, but wanted to ask if there was a particular place I should look?  I have very little experience with this so use small words. hi hi!
>
>  





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[Don Wilhelm-4]

Matthew,

Glad to hear you found it and now have satisfactory audio.  Enjoy the K2.

73,
Don W3FPR

Matthew Denson wrote:

> Thank you very much Don.
>
> I found exactly what you indicated.  On side of one of the filter option jumpers was basically unsoldered.  I'll tell you, I took a lot of will power to keep from reheating every joint.  "If I missed that one in my inspections ...."
>
> Tracing it down wasn't actually too bad once I checked the S-meter as Don suggests below.
>
> Well, all is good in K2 land.  I now have audio to spare.  
>
>
>
> Thanks and see you all on the air.
>
> 73, Matthew AE6UP
>
> ----- Original Message ----
> From: Don Wilhelm <[hidden email]>
> To: Matthew Denson <[hidden email]>
> Cc: [hidden email]
> Sent: Monday, August 20, 2007 3:12:00 PM
> Subject: Re: [Elecraft] Made my first contacts on my K2
>
> Matthew,
>
> Those symptoms are classic for behavior of an unsoldered or poorly
> soldered conection.  The connection changes to a poor connection when it
> is warmed slightly.
>
> You may be able to narrow it down by tapping on some of the components.
>
> Take a look at the S-meter while receiving a steady signal (WWV may be a
> good choice) to see whether there is a change in the S-meter response
> when the audio volume decreases.  If it does, the problem is in the
> early stages of the receiver (IF amplifier and toward the antenna), but
> if the S-meter does not drop, the problem is at the product detector or
> other stages toward the audio section.
> It also could be the AGC itself that is causing the problem.  Again, the
> S-meter is an indicator - if the S-meter increases when the audio drops,
> then the problem is with the AGC.
>
> If you find problems with the AGC or the audio itself, check the control
> board, and perhaps even reflow the soldering with an iron temperature of
> 700 to 750 degrees.
> If the problem is with the front end of the receiver (antenna to IF
> amplifier), then look carefully at the RF board.
>
> Sorry, but in cases like this, I cannot be more specific until you can
> provide more data.
>
> 73,
> Don W3FPR
>
> Matthew Denson wrote:
>  
>> Hi All,
>>
>> Building the K2 was a lot of fun, and now my basic K2 (#6210) is on the air.  I've made contacts with OR and MI from my location here in CA.  Been able to answer CQs on the first try both times.  Really lovely.
>>
>> I do have one thing that is nagging at me.  The audio level seems low.  When I first turn on the rig the level seems right.  I have to turn the AF Gain down to be comfortable.  But after a few minutes (8-10) the audio level drops all at once.  It is still usable but it can't be right.
>>
>> I am going to build the crystal oscillator to do some signal tracing, but wanted to ask if there was a particular place I should look?  I have very little experience with this so use small words. hi hi!
>>
>>  
>>    
>
>
>
>
>
>       ____________________________________________________________________________________
> Park yourself in front of a world of choices in alternative vehicles. Visit the Yahoo! Auto Green Center.
> http://autos.yahoo.com/green_center/ 
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
>  http://mailman.qth.net/mailman/listinfo/elecraft   
>
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> Elecraft web page: http://www.elecraft.com
>
>
>  

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