EMRFD Message Archive 9001

Message Date From Subject
9001 2013-08-21 14:56:43 Peter Parker Wideband RF phase shift circuit
Wonder if anyone's tried this:


Wide-band passive AF phaseshift network makes direct-conversion SSB
generation possible Bridge networks each provide 45°phase shift, to give
differential phase shift of 90°over entire frequency range with maximum
phase error of about 1° Overall loss of network is about 6 dB,T1,T2,and T3
are wound on Neosid 1050-1-F14 of Indiana General F684-1 balun core. Twist
together three 7-inch lengths of No. 26 enamel and wind 3 turns through the
two holes. Connect two wires in series for 200-ohm windings. Article gives
data for winding all other coils.-R. Harrison, A Review of SSB Phasing
Teqhniques, Ham Radio, Jan. 1978, p 52-62.

There are many adjustments but with modern equipment this should be easier
than it was.

73, Peter VK3YE
9002 2013-08-21 19:08:09 kb1gmx Re: Wideband RF phase shift circuit
9003 2013-08-21 19:31:03 Dave Re: Wideband RF phase shift circuit
ECL flip flops are not extinct. In my UHFSDR, I use 2 SY10EP52
following a grade A (3.5 to 1400 MHz) LVPECL Si570. The LVPECL flip
flops are guaranteed to a min of 4 GHz! Price is under $4 each. The
LVPECL Si570 has 2 180 deg. outputs, so 2 of the SY10EP52's will
generate I and Q LO at 1.75 to 700 MHz. With PowerSDR and NO hardware
adjustments, I can't see the opposite sideband at 432 MHz. The LVPECL
outputs directly drive a ADE-2ASK DBM through a 3 dB pad.

Dave - WB6DHW

9004 2013-08-22 01:48:30 Ashhar Farhan Re: Wideband RF phase shift circuit
It promises 1 degree error. That's quite a lot in phasing systems. You
can acheive far more for possibly less with a single 74AC74.
- farhan

9005 2013-08-22 15:04:21 kb1gmx Re: Wideband RF phase shift circuit
9006 2013-08-22 15:12:35 kb1gmx Re: Wideband RF phase shift circuit

Yes, you understand. Old (slow) parts VS modern and much
faster parts. Even at that the RC network was limited in
the same range.

The significance of the article was that it was a indicator
of what could be done and even the article suggested that
better parts on the horizon could significantly improve

An example of that was Tayloe's design with a QSD mixer
driven digitally and feeding opamp based allpass phase
shifter. That produced a receiver that is a stellar