[Hallicrafters] HT-32 Mystery Circuit

[Al Parker]

Hi guys,
    I just found it, "Modifying the HT-32", by Ross Fox, W8PZX, in CQ mag, 
Feb. 1965.
    I've been planning to do it to my HT-32 as it's awfully easy to 
overdrive it, and it sounds so great, according to reports, when set right.
    I'll scan it in the AM and send it to Harry, Jim, and anyone else who'd 
like it.  The ALC mod looks like a grand total of about 7 simple components.
73,
Al, W8UT
New Bern, NC
www.boatanchors.org
www.hammarlund.info

----- Original Message ----- 
From: "Jim Zellmer" <jim at ka0vsl.com>
To: <kt4ae at bellsouth.net>; <hallicrafters at mailman.qth.net>
Sent: Monday, March 31, 2008 7:58 PM
Subject: Re: [Hallicrafters] HT-32 Mystery Circuit


> Those diodes might be a modification for an (AALC) amplified automatic 
> load control like the one in the HT-32B.  I seem to remember a segment is 
> a old Hints & Kinks manual about this one.  I will have to rummage through 
> my old books and will scan a copy if I find it.
>
> Jim Zellmer
> KA0VSL
>
> Harry Vaught, KT4AE wrote:
<snip>
>> In the compartment under the finals there is an added terminal strip. On 
>> it are a couple of 1N33 diodes, a .47 mfd cap, 3-.1 caps and a couple of 
>> resistors across the caps.  It's hooked in some subtle way to the finals, 
>> but I couldn't figure it out with all the back and forth.  The caps are 
>> 200 volt units so they aren't dealing with high voltage.  From this 
>> circuit there are two wires running to the SSB deck and are in series 
>> with the normal lead to the contact on the Function switch (wafer 1R) 
>> which is selected in USB or LSB.
>>
>> From this limited description does anyone get a glimmer of what this 
>> might be? A limiter?  ALC?  The thing doesn't act like it has either a 
>> limiter or ALC.  It's easy to over-drive, as is normal with these units.
>>
<snip>