[Heathkit] More on HW-101 Finals

[Kenneth G. Gordon]

On 5 May 2007 at 15:54, Ted Bruce wrote:

> This from RF Parts Company's web page, which seems to
> support Glen's assertion on the subject:
> 
> "6146W-GE (GE Brand) is not recommended for Kenwood
> transceivers, and is not interchangable with the
> 6146B."

Right.

> 
> Well, the pair I pulled out were GE 6146-B tubes,
> which a Heathkit HW101 bulletin (#89, I think) said
> that the GE 6146B tubes were finally deemed
> appropriate for the HW-101.

I just re-read that bulletin: what it says is that certain 6146Bs have 
been, "...reworked by GE..." to be suitable for use in the HW-101 (and 
the other SB/HW rigs). These have 6146B etched in the glass 
somewhere, but say 6146A in paint on the tube or on the base also. 
That bulletin also says that 6146A tubes are "...no longer available from 
the manufacturer..."

> I still haven't done the neutralization without plate
> and screen voltage.

That method works best for me. However, you also have to be very 
careful about the neutralizing wire that is used for the driver tube. If that 
wire is stuck down into hole "W" much more than about 1/8 inch, it will 
make it nearly impossible to neutralize the finals.

> with the HW-101, I have significantly
> lower output on 10m.

How MUCH lower? It is supposed to be somewhat lower. I get between 
90 and 95 watts output there as opposed to at least 100 watts on all 
other bands, and over 110 watts output on 80.

>  I bought a 6GH8A locally, as
> Gordon suggested, as a replacement for the 6EA8 for
> the mic amp yesterday, so back to work on the HW-101.

Well, the 6GH8A works great for me.

I also use 6AH6s as the receiver RF amp and 1st mixer tubes since 
6HS6s are so hard to find.

I have been using a pair of real 6146Bs (not the etched kind) in my 
HW-101 for the past year, and they have worked just fine, but I had to 
be extremely careful about the neutralization, both for the finals and for 
the driver. I used the remove-the-B+ method to neutralize the finals.

The problem I am having now with my HW-101 is that the VFO won't 
track properly. According to one of the HW-101 bulletins, I have to 
change a capacitor in the VFO.

Ken Gordon W7EKB