[Boatanchors] 17 M xtal for KWM-1

[Bill Cromwell]

Alex AI2Q wrote:

To determine the xtal frequency you need to look at the rig's
conversion 
scheme, and have your calculator in hand.

To put my KWM-1 on 17 meters I determined that an 11.034 Mc rock would
be 
doubled to 22.068 Mc. Then, subtracting 4 Mc would yield tuning at
18.068 
Mc. Subtracting 3.9 Mc would yield 18.168 Mc.

Wishing to use what I had on hand (namely a KWM-2A military xtal pack),
I 
deployed a KWM-2A's 11.0775 Mc crystal. That delivers coverage in my
KWM-1 
from 18.14 through 18.168 Mc. The dial reads from 085 to 013. The dial
at 
0.0 corresponds to 18.153 Mc.

Vy 73, AI2Q, Alex

Hi Alex,

I "think" that radio is one that covers it's chunk of spectrum in 200 kc
'bands'. From the math you presented it has a 4 mc I.F. and the crystal
oscillator is doubled to be 4 mc higher than the incoming frequency. Is
that correct? In the next part of your info I come up with something
different for your coverage from the 11.0775 rock.

So a KWM-1 owner can determine from your math where the xtal they just
happen to have will fall on the KWM-1 coverage. If I have the info about
the I.F. and oscillator doubling then a 11.0 mc xtal will give coverage
of the 17 meter band with the dial zero at 18.000 mc and the beginning
of the 17 meter band starting at .068 on the dial. So if an owner has to
buy a crystal that's what would be ordered. (It's what I would do)

Trying it two different ways I come up with coverage on your rig
starting at 18.155 (Dial = zero). What did I overlook? Maybe the 11.0775
crystal is a bit "off" in the KWM-1? I am also guessing your dial goes
down past zero to yield 18.140 at the very end. I have found that
crystals vary by that much from transmitter to transmitter and unless
you have a way to net them you live with it wherever it lands.

73,

Bill  KU8H