"H. P. Friedrichs" wrote in message
news:1YOdna1FqcOin2DZnZ2dnUVZ_tCdnZ2d@velocitywest .com...
I am interested in the origins and purpose of the "IRE (Institute of
Radio Engineers) Standard Dummy Antenna," as used during the alignment
of radio receivers.

I first came across this circuit in some old Hallicrafter's
documentation, which described the alignment of a particular radio. The
"IRE Standard Dummy Antenna" consists of four components--- a 200pf cap
in series with a 20 uH inductor, which links the signal generator to the
receiver's antenna input. A 400 pF cap in series with a 400 ohm resistor
is connected in parallel with (shunts)the inductor.

I gather that this circuit models a wire antenna of some type. Is this
true? What is the import of the component values and how were they
arrived at? I modeled the circuit in Spice and graphed the transfer and
impedance curves but it is not entirely clear to me what benefit there
is to using this circuit.

I've also Googled this and found some references here and there, but
nothing explains the "why" of it.

Is there anyone who can shed light on this?

73
Pete
AC7ZL

Yes, the dummy antenna models a wire resonant at 2.something Mc. I suppose
that was taken to be more or less typical of the receiver antennas of the
30s. The dummy antenna's most important use is as a standardized load for
measuring receiver sensitivity. Terman's Radio Engineer's Handbook has a
few paragraphs on this.

If you're just adjusting the RF coils, peaking them up on the antenna
normally used would be as good or better. Any sort of loose coupling
between the generator and RF coils will get you in the ballpark with most
radios.

Frank Dresser