[Elecraft] Low voltage on AGC threshold

[John R. Lonigro]

Mike:

How accurate is your DMM?  The 8v and 5v regulators should still produce 
8 and 5 volts even with a slightly low supply voltage.  Also, if the 
K2's internal voltmeter reads the same as your DMM, that tells me your 
DMM is reading low because there is a diode in the K2 power line which 
will make the K2 internal voltmeter read LESS than an accurate external 
DMM.  Only if the external DMM reads low would the two voltmeters agree.

Try to check your voltages with a different DMM.  My guess is your 
problem is NOT low voltage all around.  Good luck.

73's

John AA0VE

Mike, W8ENG wrote:

>This is an update to my earlier post.  I touched up a solder joint and
>reassembled the radio.  The voltage on pin 5 of U2 was still 3.78 volts,
>with the RF gain set fully clockwise.  The input voltage from my power
>supply was 12.4 volts, both on my DMM and on the K2's internal voltmeter.
>The voltage out on the 8v regulator was 7.8,a nd on the 5v regulator was
>4.9.
>
>I'm thinking that the problem may be low voltage all around.  I don't have a
>better power supply to check with at a higher voltage.
>
>Any addational help or comments would be appreciated.
>
>73,  Mike, W8ENG
>  
>