[Hallicrafters] Hallicrafters Digest, Vol 96, Issue 5

[James Liles]

Hi Joe:

That is a common problem.  In most cases it is caused by one or two 
different errors.

1. The alignment of the 50.75Kc is aligned at 50.5Kc or not at all.  The 
Mark1 used 50.5Kc and Mark2 50.75Kc.  The fundamental reason that it was 
changed to 50.75 was the BFO can feed backward through V7 to  T6 to T5 to 
the AVC diode in V7.  They originally thought it was a adjacency problem 
because the BFO and AVC detector are in the same envelope but aligning at 
50.75Kc mitigates most of the problem.  A good way to verify alignment is to 
vary the BFO and see if the S-Meter varies with it in CW/SSB mode.

2. Check to see if the variable band pass caps were replaced and if so what 
type of cap.

Don't exactly understand the statement regarding AM mode??

Kindest regards Jim K9AXN


-------------- ORIGINAL MESSAGE ------------------------

Message: 5
Date: Wed, 4 Jan 2012 21:17:19 +0000 (UTC)
From: k7mks at comcast.net
Subject: [Hallicrafters] SX-100 MK 2 - Wierd S-meter
To: hallicrafters at mailman.qth.net
Message-ID:
<988122591.283528.1325711839308.JavaMail.root at sz0115a.emeryville.ca.mail.comcast.net>


With no antenna connected and mode in AM the S-meter will barely set at zero 
on all bands.? Connect a small antenna and tune to a "no?signal" frequency 
and ?the meter will no longer zero.? It?seems like it is showing white 
noise.?? Switch mode to CW/SSB and it will not approach zero adjustment.? 
This may be nor mal as the manual does no t mention the meter works in 
CW/SSB.? V-4 has been replaced with no improvement

?

I've heard that the S-meter zero on the SX-100's can be a challenge to 
accomplish.? True?or False?

?

Thanks for your helpful comments.

?

Joe k7m ks