[ForSale-Swap] Re: GB> Re: BC221

[MillerKE6F at aol.com]

In a message dated 8/25/2006 9:34:40 A.M. Pacific Daylight Time,  
kd4e at verizon.net writes:

http://www.btinternet.com/~allan.isaacs/bc221.html


Nice little ditty on the BC221
 
    These are amazing little (little by 1940  standards)  instruments and 
I've been collecting these toys and their Navy  (LM) equivalents for many years.  
And they are truly amazing in that they  all operate quite well despite their 
50-60 year ages.  
 
    I have a few that allow me to easily get within  25-50 Hz of any 
frequency on the lower ham bands without any tricks other than  making sure the 1MHz 
crystal was on the money and that the gear system was clean  and properly 
lubricated to minimize any backlash. 
 
    Back in the 1950s most of the participants in the  ARRL frequency 
measurement contests (FMTs) used either BC-221 or LMs.  and  were able to get within 
fractional parts per million readings.  There were  a few adventuresome folks 
who mad a minor modification to the units to whit  they  heterodyned the  low 
frequency band of the instrument against  the 1 MHz calibration oscillator 
harmonics to get more resolution.  I can't  recall the details of the mod, but 
would sure like to see it again.   Perhaps one of the other Senior Mates on the 
Glowbugs list could remember and  make that little trick available.  
 
    Tnx for the read.
 
 
    Bob, KE6F