[Heathkit] Re: CWF-2 Audio Filter and HW-16s.

[Kenneth G. Gordon]

On 28 Jun 2006 at 21:12, Tom NØJMY - AAR7FV wrote:

> that I've had.  I usually end up taking them out of their cabinets and
> installing them behind the detector in HW-16's. 

Tom:

I just did that to my HW-16. I also included the 4th selectivity position of 
the CWF-2, so that I have (what is it?) 180, 110, 90, and 80 Hz 
selectivity.

Trouble is, my HW-16 has a LOT of hum, especially with the volume 
control all the way down, and so far, I can't figure out where it is coming 
from.

I have taken it down the the shop at work and intend to follow the hum 
around with a scope until I find it. I know it is not coming from any place 
ahead of the audio amp stages. If I yank the 12AX7 product 
detector/bfo tube, there is no change.

I also have a problem with my HW-16 in that there are terribly loud 
clicks in the headphones or speaker, but not on the air, when keying 
the darned thing.

I've tried several different methods for minimizing those, but have not 
yet succeeded in finding a proper cure.

I'm not even sure where it is coming from yet. I know at least one fellow 
attempted to add a limiter to the receiver to take that out, but it didn't 
work very well for me.

I wonder if anyone else has had this problem and fixed it?

Lastly, it turned out that the reason I couldn't get any audio through my 
audio amp stage was that I had inadvertently installed a 270 K ohm 
resistor in the cathode lead of the 6HF8, instead of the 270 ohm 
resistor that it should have had. Therefore the audio amp stage was 
cut-off.

Ken W7EKB