EMRFD Message Archive 1714

Message Date From Subject
1714 2008-06-16 08:25:41 cwfingertalker VFO toroid phase splitter
Hello emrfd group,

I am planning a single band transceiver. What I want to do is "split"
the output of the VFO. One signal would to to the receiver mixer and
the other to the transmitter mixer. I have looked at FET and toroid
phase splitters and think the toroid is the way to go. I understand
it should be a bifilar wound coil fed at the midpoint by the VFO with
the two outputs on the opposite ends of the windings. My problem is I
don't seem to find any criteria for winding the toroid. How do you
figure out how many windings is correct? The VFO will run 1.8 to 2.0
mhz mixed with a 9 mhz carrier oscillator for an output on 7 mhz.

Thanks in advance for some help

Bill N7EU
1719 2008-06-16 12:37:49 Wes Hayward Re: VFO toroid phase splitter
Hi Bill,

This is Fig 3.81 on page 3.36. The ferrite winding is not very
critical at all. I've used this scheme in a lot of rigs. For
example, see Fig 6.150
1720 2008-06-17 06:51:02 cwfingertalker Re: VFO toroid phase splitter
Hello Wes,

Thanks for the references. I have those pages highlighted. I was
just concerned there might be some criteria I was missing or not aware
of. The mixers will be identical so I am hoping to maintain the match
on all ports. This makes three projects going at one time. Thanks again.

Bill N7EU