[Hallicrafters] Aligning a S-76

[kenneth hittson via Hallicrafters]

Hi Jim
My set had 2 paper caps in the sub-chassis. C23 had the wax end cap pushed off and it was dangling on the lead. I did get both manuals off Bama, but they are not great in regard to resolution. I have ordered an updated manual from a supplier, hoping for the best. 
I believe I will pull the sub chassis off again and replace all of the connector wires, and the coax. Or at least ohm to the tube socket. 
Thanks very much, I certainly appreciate the help.
Sincerely
Ken

-----Original Message-----
From: "Jim Liles" <hallicrafterssr2000 at k9axn.com>
Sent: ‎8/‎11/‎2015 11:13 AM
To: "Chris Farley" <kc9ieq at yahoo.com>; "hallicrafters at mailman.qth.net" <hallicrafters at mailman.qth.net>
Subject: Re: [Hallicrafters] Aligning a S-76

Does anyone have a copy of the service bulletin that speaks to the updated 
alignment procedure for the S76?  There was one for most later radios with 
the 50Kc system and one for the S76.

Regards Jim K9AXN

-----Original Message----- 
From: Jim Liles
Sent: Monday, August 10, 2015 7:44 PM
To: Chris Farley ; hallicrafters at mailman.qth.net
Subject: Re: [Hallicrafters] Aligning a S-76

Ken,

Do you have the users manual with schematic?

Chris and Grant are right about the sense point.

Step 1 50Kc:  V3 is removed.  The injection point is Pin 1 of T2 not L6. 
There is no voltage on that pin of T2.  The sense point is AVC because you 
are aligning the .5Kc bandwidth position to anchor the 50Kc I.F. system. 
The injection is un-modulated because it is the .5Kc position.

Step 2 1650Kc:  Askes you to use a modulated injection signal.  Read through 
it a few times after you get the 50Kc right.  It is essentially written to 
center the 5Kc wide 50Kc signal in the center of the wider 1650Kc pass band. 
The radio is set to band 1 and a modulated 1650Kc signal is injected into 
the grid of V2 the first mixer simulating a signal from the antenna.  This 
step senses at the speaker leads because it is modulated and 5Kc wide.

There are no paper capacitors under the sub-chassis.  I would not remove it 
unless you measure a defective component.  You can measure all components 
from tube pins and under chassis connections.

Thoughts?

Kindest regards Jim K9AXN


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