[Elecraft] KX1 - Low Power Output

[Don Wilhelm]

First, check the soldering carefully.  If the solder connections look 
convex (like a ball on the component lead), the connection did not 
receive enough heat to flow the solder adequately onto the solder pad.  
If there is excess solder, wick it away and re-solder with a minimal 
amount of solder and adequate heat (at least 700 deg F).  Watch the 
solder flow - if it flows out to a thin, almost invisible, edge on both 
the solder pad and the component lead, that is a good connection.  The 
solder should be a bit concave - if it looks convex, it either has too 
much solder or did not receive enough heat or both.

Check the low pass filter toroids (and T1 and L3 too) to be certain the 
leads have been well stripped and tinned - if the solder connection 
looks like a miniature volcano, you have a bad connection and the only 
cure is to remove the toroid, re-tin the leads and re-solder it - you 
cannot do a proper job of it while mounted on the board (I have tried 
many times).

These two problems are the root cause for more than half of the repairs 
I do.  It is seldom that I have to replace a part because it failed.

If you have questions about how a good solder connection should look, 
check the drawings in the soldering tutorial on the Elecraft website 
(and now being shipped with many of the kits).

73,
Don W3FPR

Oliver Olsen wrote:
> Hello,
>
>  
>
> I recently constructed a KX1 with the 30/80 meter option board, and I'm
> having problems with low power out on all bands except 80 meters.  On a
> 13.8V power supply, I'm getting a hair over 3 watts, but only .5 - .7 watts
> on 20 meters (measured on a 50 Ohm dummy load).
>
>