[Hallicrafters] HT-32 Mystery Circuit

[Harry Vaught, KT4AE]

Thanks, Al and Jim.

It certainly sounds similar.

My HT-32 showed no signs of having an ALC, but maybe it was the 
forty-year old caps.  This will let me check it out.

Harry, KT4AE
Maryville, Tennessee

Al Parker wrote:
> 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>
> 
>