K2 AGC set

[Jack-123]

Setting the AGC threshold on my K2.

Adjusting R1 for 3.8 volts. But turned full up I can only achieve 3.666
volts.

Is this a problem?

73
Jack VK2CJC / MM0AXL
FISTS #9666 - CW QRP Club #753 - Elecraft K2 #6404
Mid North Coast Amateur Radio Group  www.mncarg.org
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[Don Wilhelm-4]

Jack,

The cause of the low AGC Threshold is a low output from the 8 volt
regulator (Control Board U4)
It will llikely not cause any problem at all if you simply set the
Threshold to max.  You could consider replacing the regulator if it
causes you concern.

73,
Don W3FPR

Jack wrote:
> Setting the AGC threshold on my K2.
>
> Adjusting R1 for 3.8 volts. But turned full up I can only achieve
> 3.666 volts.
>
> Is this a problem?
>
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[Jack-123]

8v regulator output was 7.96v.

Thanks for the input guys. I'll finish the rig then set again.

cheers
Jack VK2CJC / MM0AXL
FISTS #9666 - CW QRP Club #753 - Elecraft K2 #6404
Mid North Coast Amateur Radio Group  www.mncarg.org
For MSN Messenger, use this emails return address

----- Original Message -----
From: "Don Wilhelm" <[hidden email]>
To: "Jack" <[hidden email]>
Cc: <[hidden email]>
Sent: Thursday, February 28, 2008 3:16 AM
Subject: Re: [Elecraft] K2 AGC set

> Jack,
>
> The cause of the low AGC Threshold is a low output from the 8 volt
> regulator (Control Board U4)
> It will llikely not cause any problem at all if you simply set the
> Threshold to max.  You could consider replacing the regulator if it
> causes you concern.
>
> 73,
> Don W3FPR

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[Don Wilhelm-4]

Jack,

An 8 volt regulator voltage of 7.96 volts should allow you to set the
AGC Threshold higher than you reported.  Did you have the RF gain
control all the way to the clockwise rotation stop?

The voltage at U2 pin 5 is determined simply by a 3 branched resistive
divider which involves the RF Gain, Control Board R1, and Control Board
RP6, so you apparently have either a high resistance connection
somewhere or you have an incorrectly placed resistor (or control pot).
Check All connections to (and values of) R1, RP6, the RF Gain control
and the connectors between the Control and RF boards as well as the
connectors between the RF Board and the Front Panel board.

73,
Don W3FPR

Jack wrote:

> 8v regulator output was 7.96v.
>
> Thanks for the input guys. I'll finish the rig then set again.
>
> cheers
> Jack VK2CJC / MM0AXL
> FISTS #9666 - CW QRP Club #753 - Elecraft K2 #6404
> Mid North Coast Amateur Radio Group  www.mncarg.org
> For MSN Messenger, use this emails return address
>
> ----- Original Message ----- From: "Don Wilhelm" <[hidden email]>
> To: "Jack" <[hidden email]>
> Cc: <[hidden email]>
> Sent: Thursday, February 28, 2008 3:16 AM
> Subject: Re: [Elecraft] K2 AGC set
>
>
>> Jack,
>>
>> The cause of the low AGC Threshold is a low output from the 8 volt
>> regulator (Control Board U4)
>> It will llikely not cause any problem at all if you simply set the
>> Threshold to max.  You could consider replacing the regulator if it
>> causes you concern.
>>
>> 73,
>> Don W3FPR
>
> _______________________________________________
> 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   
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
>

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