[Hallicrafters] Summary - SX-96/100 microphonics topic

[Chris Kepus]

Please note this revision: 

"I meant to say solder the wipers to the capacitor frame." From Carl KM1H
Revision incorporated below: (thanks, Carl)

-----Original Message-----
From: Chris Kepus [mailto:ckepus at comcast.net] 
Sent: Wednesday, November 23, 2011 10:16 AM
To: 'Chris Kepus'
Subject: Summary - SX-96/100 microphonics topic

Thanks to all who commented on the microphonics topic.  

The consensus or solitary views on several points are:

The equipment, as shipped NIB from Hallicrafters, was free of microphonics.

The variable cap assembly (main tuning and BS) could be a contributor to
microphonics.  Clean bearing races on the main and BS caps; use alcohol or
acetone then repack using moly grease.

Tighten all the screws for terminal strips that are used as grounds and
solder all of the rivets that hold tube sockets to the chassis and that are
used as grounds.
  
Tap on tubes and other components to help identify possible contributors to
microphonics.  When found, remove and replace (substitute) and/or tighten as
appropriate.

Thoroughly clean (and lube if applicable) all moving electrical contacts,
tube pin sockets, and mechanical bearing / metal to metal surfaces with
appropriate stuff.

Solder the spring brass variable cap wipers to the capacitor frame. (revised
11/23)

Place receiver on thick foam pad.  Do not touch table or breathe on
receiver.

If your efforts are not making any difference, your BP goes thru the
ceiling, and your receiver still continues to yowl, yelp, and squeal, put
lipstick on it (your choice of color, location, and coverage) and SELL THE
SQUEALER!!!!  (on eBay of course:  description should include (but not
limited to) the following words and phrases: AS IS.. lights up...worked well
when purchased...audio has excellent sonic range...lipstick is not
contaminated....)!!  

Happy Thanksgiving to all.  Give special thanks for the new sunspot cycle.
Happy radioing.

73,
Chris
W7JPG