[Elecraft] XV-144 Overdrive protection

[Don Wilhelm]

Andrew,

Some transverters suffer from false overload detection due to noise on 
the DC circuit to the microprocessor.
The cure I have found effective is to remove the front panel metalwork 
and solder a 0.1 uF capacitor between the collector and emitter of Q7.

If you do not have the two 0.1 uF capacitors on the 5 volt regulator and 
the 10 uF electrolytic across the 5 volt line (between pins 1 and 2 of 
the main board P1) they should be added as well.
See 
http://www.elecraft.com/Apps/XV_Bypassing_Cap_Builder%27s_Alert_Rev_A.pdf

73,
Don W3FPR

On 2/13/2014 5:09 PM, Andrew wrote:
> Hello
>
> Just starting Part VI-Filter Alignment, other tests prior worked no problem.
>
> Using a KX3 on 5 watts with XV-144 set to 5 watts input.
> With key line and coax from ant socket (kx3) to XV-144.
> Dummy load via power meter connected to output of XV-144.
>
> The XV-144 goes into overdrive protection whatever power I apply to the
> input all I get is the power led's flashing on the front panel.
>
> Any ideas where to look, am I missing something?
>
>