I would think a 13 MHz IF would reasonably work well with a 5 MHz VFO.
There are 13 MHz crystals available in the 13 MHz range.
Mouser has 12.96 MHz crystals in stock, 520-HCU1296-18X. This would
place the 3rd harmonic of the VFO at 15 MHz, and the 4th at 20 MHz, to
move it as far as possible from 18 MHz. Running the VFO at 5 MHz is
not too bad.
- Dan, N7VE
--- In BITX20@..., "Ron [W5RCM / ZS1MCD]" <w5rcm@...> wrote:
10 MHz IFs in the US can be problematic with WWV broadcasting there.
72, Ron McDowell - W5RCM / ZS1MCD
Austin TX / Hermanus ZA
w5rcm [at] Ham-Stuff [dot] NET
Greg Derda wrote:
Now that I have completed my BitX20a, I have started another BitX
the Far Circuits boards, and I would like to build this one for 17
meters. I've found some very useful information in the messages,
files, and photos archives of this group, but so far, I have not seen
mention of the IF frequencies people have used for 17m. Although I
have a couple of potential DDS options available to me, I don't know
that I want to use such a "valuable resource" on the narrow
of a 17m rig.
Options that come to mind for a traditional IF/LO combination are
(presuming a 18.1Mhz target):
14.76 3.34 (chosen as an oddball example using available oddball
I don't see many HF VFO's in the 8Mhz range, so I am guessing it
common. I have crystals for the latter two options easily
me and am leaning toward one of them.
I guess that instead of babbling on with guesses, I'd like to just
Does anybody have suggestions for a good IF/LO combination?