[Elecraft] K2 and HW-101? Swamping Resistor

[N2EY@aol.com]

In a message dated 1/15/02 9:57:48 PM Eastern Standard Time, k0wa@swbell.net 
writes:

> Place a 50 ohm 
>  10 watt non-inductive swamping resistor from the grid connection to 
>  ground.  You should have a blocking capacitor in there also.  As long as 
it 
>  is AB1, I think you could get away with it.  If I am not mistaken, the 
>  HW101 as did all those rigs...run at AB1 or was it AB2 to get a little 
more 
>  power output?  The other thing I would do is  to place a small MFJ tuner 
>  before the amp...but I doubt you would need it.

This won't work very well.

First off, the bias on the final must not be shorted to ground. Second, there 
needs to be an impedance step-up because the 6146 grids need more RF voltage 
than a K2 can develop across 50 ohms.

The biggest challenge is getting the TR system right.
>  
>  The resistor has to be non-inductive...carbon composite.  I wonder if 
>  anyone out there has a HW100 or HW101 who would like to 
>  experiment????  Yes, I think you could do that with a 807, or 813 as well.
  
>  The only difficult things these days is to get the HV.  That is where the 
>  Heath gear would be good if you could get one of those shoe-box power 
>  supplies as well.
>  
All you need is a TV power transformer, some diodes and filter caps.

I may just try this on a basket-case HW-101 I have. Tear out all but the 
final and work out some sort of TR system. Power supply might be built on the 
liberated chassis space. 

73 de Jim, N2EY