[Hallicrafters] Indentifing capacitors (?)

[Troglodite at aol.com]

In a message dated 9/16/04 8:18:12 PM Central Daylight Time,  
k2wh at optonline.net writes:

I'm restoring a SX-24 and having some trouble finding some of the caps  with 
the exact values.
Some are close, but I'm not sure if they would be  close enough.

Example:
Will a .022 mfd 630 vdc work in place of a .02 mfd 600vdc  ?
and
Will a .0047 mfd 600 vdc work in place of a .005 mfd 600vdc ?
 
--------------

The short answer is yes. Most of the old wax/paper capacitors were not  
critical.

There are as many opinions on this as there are brands of capacitors.  :-) 
Likewise, some people don't believe in a "bulk" recap of all the old  wax/paper 
capacitors. Personally, I replace ALL the wax/paper capacitors in any  radio I 
restore. The ceramic and mica caps I leave alone unless I find a bad  one. 
Resistors are checked for tolerance and replaced if off by more than 20%.  
Electrolytics are almost always replaced. In the long run I think it saves a lot  
of time.

If you are getting into restoring old gear, it pays to build up  a stock of 
common values. Buying in bulk is one way to do this. Check this  source for 
quality inexpensive poly capacitors.   _http://www.radioantiques.com_ 
(http://www.radioantiques.com) 

Also,  since the replacement capacitors are usually smaller than the old 
ones, use  insulated sleeving where required. Install the capacitor using the same 
 connections that were used for the original - avoid the temptation to use a  
closer "ground" for example. If you try to second guess the original 
engineers,  you will usually end up with the short straw. They had the advantage of  
statistical data from a production run to determine optimum parts  placement.

If there is a capacitor from the AC line to the chassis, this  should be a 
type approved by the safety agencies for that purpose. These  capacitors are 
available from Digi-Key and others. An ordinary 600V capacitor  should not be 
used in this spot. If you have one of these and have trouble  finding a proper 
replacement, drop me a line and give me the value you need.  It's worth a 
capacitor sent in the mail to keep another old radio enthusiast  alive.
 
Regards,
 
Doug Moore KB9TMY