[Drake] Drake 2B AVC

[Garey Barrell]

Hi Kees -

Have you checked the timing caps for the AVC.  The stock AVC circuit 
works just fine as long as there are no faults.  It  _IS_  however a 
VERY high impedance circuit.  There are also terminals on the back to 
allow addition of a supplemental AVC timing cap if you want "really 
slow" AVC.  I have seen cases where there is accumulated crud under that 
terminal strip,  forming a leakage pathThe 2-B is one of the "classic" 
circuits of all time!  :-)

Also, if you haven't already, replace the 6U8 with a 6EA8.   Helps a 
little in the First Mixer slot, and makes a big difference in the 
reliability of the HF Oscillator, especially on 40M.

73, Garey - K4OAH
Atlanta

Drake C-Line Service Manual
<http://www.k4oah.com> 



windy10605 at juno.com wrote:

>I have a Drake 2B and found the "common" 2Meg AVC pot to ground leakage
>path (unable to adjust the AVC "sensitivity" level), cleaned the pot
>after taking it apart, and can now adjust for the required -1.5V bias
>level. The S-meter still barely registers and the sensitivity seems to be
>lower than it should be. Has anyone come across the same problem ? Know
>of any AVC circuit redesign or things to check ?
>
>73 Kees K5BCQ
>
>  
>