Topband: Henry 3K-A 160 mts Band?

[Harold Smith]

George:

I am very familiar with the Henry Amplifiers

I have to agree with you that the addition of 160 would be a nightmare. In
the Heath amps one could add a toroid in series with the plate coil and
switch it in and out with a Rj-1a vacuum relay in the 80 meter position. A
modification switched in and out in the input circuit with a reed relay
works fine.

I did this to my homebuilt 2 x 3-500Z amp and it worked fine. If I remember
right, I used a toroid coil of 10 microhenry wound on 2 Ft200-2 cores with #
14 wire (1.5mm2). Put teflon tubing over the enamel coated wire and wrap the
toroid forms with glass tape and a heavy coat of Q dope before winding.
Also, I had to bypass the plate choke with 5 more .001 x 6kV disc ceramics.
I used a B&W 801 plate choke. Now I would purchase an Ameritron Al-1500
plate choke. Perhaps increasing the bypass caps on the filament choke might
be in order.

I added a spst toggle switch and actuated the added relays for 160 in the 80
meter position. I saw the same output on 160 as 80 meters ~1400 watts.


Now it sits in the corner, since I have an Alpha 77DX. I also have a plain
Alpha 77 with their 160 mod. Yes the original Alpha had the switch position
but the 160 components were not installed.

73 de Price WØRI and St. Louis Low Banders Club WØCKC



----- Original Message ----- 
From: "George & Marijke Guerin" <gmguerin at voyager.net>
To: "Javier Remoto" <jlopez at plasticosomega.com>; <topband at contesting.com>
Sent: Sunday, July 18, 2004 9:45 AM
Subject: Re: Topband: Henry 3K-A 160 mts Band?


> Javier,
>
> I have not seen any mods for a Henry amplifier to 160 meters.  If you can
> find an SB-220, it is much easier to make it a single band amplifier for
> 160, and there are articles on how to make the conversion from 80 to 160
> meters and use higher bands.
> I believe it is a lot easier than trying to rework the Henry, which I
would
> not do.
>
> Most Henry amps have a roller inductor and fixed tuning capacitors in the
> plate tank circuit, and one would have to add fixed inductance for 160 as
> well as add padding capacitors to the existing capacitor.
>
> Just my personal opinion.
>
> 73    es Buena Suerte
> George
>