[HBR] options for the 2nd oscillator

[Walt Hutchens]

John Landrigan said:

> It is beginning to appear that a 1650, 1685 or 1700 KHz crystal that can take
> the voltages present in vacuum tube oscillators is not going to be found.

Where are you looking?  This oscillator doesn't have to run any significant
power -- actually, it SHOULDN'T, since unnecessarily high power will lead to
drift and other problems.  Any HC 18 crystal should work just fine --
basically anything available in a leaded or plug in package of that size.
The smaller crystals may not be available at so low a frequency.

You probably need only a couple of volts p-p output so that's the ballpark
for the voltage across the crystal.

It probably will have to be a custom item and may cost $25 or so but there
are companies that do this work.

Another option is using a slightly different frequency that you CAN find and
adjusting the 1st IF accordingly.  This will in turn require a slight change
of the 1st oscillator frequencies but 50 kcs one way or the other won't be
enough to require changing the number of turns on the coil.

Tom wondered:
> Q.  On BBOD's (Black Beauties of Death) - does one read the color bands like
> normal?  i.e. org, org, red - 3300 pf?

That sounds right.   There may be two more bands with the voltage rating and
tolerance.  Any of the Handbooks should have the info.

Walt
KJ4KV