[Heathkit] Premium tube replacement guide

[David Thompson]

In looking through an old 73 for November 1962 I came across a 2 page guide 
for a lot of those 4 digit
premium tubes.  Like the 1614 is a premium 6L6.
I have a sleive of 5726's which are 6AL5's.   There are about 5 or 6 
listings for 6AL5 replacements.  The Author, Roy Pafenberg, W4WKM gives you 
warnings on some such as 5933 (807) with a 3" greater base diameter.  Oh, 
the article is on pages 46 and 47.  Sorry no scanner on this PC.

Now if only I could find a listing for Mullard valves.

73 Dave K4JRB