[Johnson] FS: Box of FT241 Crystals

[Bry Carling]

FOR SALE:

Quantity of 52 FT241 crystals. These are the LF range crystals as 
used in the military BC620A tank radio set. Excellent condition.

During WWII these quartz crystals were manufactured for use in military 
vehicle radios.

There are two series of these ft-241 crystals, those marked with "two digit" 
channel numbers,
and those with "three digit" channel numbers. These crystals are marked for 
frequencies
in the 20 - 40 mhz range, but the fundamental frequencies are much lower. 

Some of the crystals fall in the 455 khz range, and were used by homebrew 
radio builders 
in the 1950's to make crystal filters, especially for SSB exciters (see early 
50's ARRL 
handbooks).

These are LF crystals in the 300 - 500 kHz range. Marked with channels 
such as
14, 19, 60, 68, 317, 320 (sorry no specific choices offered) but for example,
Channel 68 = 496.3 kHz.

There used to be the N4JVP calculator online here:
http://www.subdevo.com:82/FT241/FT241.aspx - maybe ask Fritz, N4JVP 
where it is now.

These can be used for experimenting and for use as a crystal lattice filter 
since several
are on the same frequecies. (These have the same pins as the popular 
FT243 crystals 
and use the same socket but the body is slightly wider)

This box of 52 crystals is available for $16.00 plus shipping.

Pictures and details at:

http://www.af4k.com/FT241_crystals.htm

73 - Brian, AF4K