Errata for Chapter 3 of EMRFD
(10 Feb 13)
p3.4, middle col, 2.4 inches below top of text.
Remove the paren
) at the end of the sentence. (15May03)
p3.6, Table 3.2. g(3) for the Wide U. Sp.
filter should be 3.352 instead of 2.352. (16 Sept 05)
3, 2.9 inches up from text bottom. Replace "texts.(ref 6)" with "texts
such as Zverev.(ref 6)"
p3.9, col 3, 1.9 inches up from text top.
Add a footnote after "Zverev's text." The note
should read "see ref 6. (15Jan04)
p3.10, middle col, 4th line down from
top: Change "he" to "the" (24Feb03)
p3.10, left column, 4.2 inches up from
text bottom: Note the first few sentences
in the paragraph beginning with "The sidebar.." Just
past the bold Table 3A that appears in text
we find "(see sidebar on page 3.14)" Move
this expression to the beginning of the paragraph so that
we now have "The sidebar equations (see sidebar on page 3.14)
may be used ......This has been done done to form Table
3A . The
inductors ......" (9Dec03)
p3.11, Fig 3.22 caption. Change 0.4 mH
to 0.4 uH. (15Jan04)
p3.12, sidebar Fig B. It's
"scraps" of circuit board material rather than scaps.
p3.14, Table 3A. The inductors are
all in uH (microhenry) rather than mH (millihenry.) (24Feb03)
p3.14, Table 3A. The filter with center frequency
of 14.2 MHz has a bandwidth of 0.4 MHz rather than the value of 0.2 MHz shown.
p3.15, middle col, 1.3 inches down from
top of text: change "coil" like structure
to become "coil-like" structure.
p3.19, right column, 4 lines up from bottom:
Replace the existing text with "Normalized Q is q0=19.2,
p3.19, right column, 1.0 inch up from text bottom.
Replace k23=0.4512 with k23=0.5412. The
filter presented in the example was designed with k23=0.4512 and
is a nicely performing filter with a slightly narrower bandwidth
than the desired one. (4 Feb 05)
p3.19, Fig 3.35. This is not a report of an error,
but rather, a revision to an existing method. Jack Smith,
K8ZOA, pointed out a very interesting omission that we made in the formula
we use to calculate motional inductance from the frequency shift in the
G3UUR type crystal oscillator. The capacitance we had used was
just the series C that is inserted by the switch, including the capacitance
of the open switch. This value should also include the crystal parallel
capacitance, or holder C as it is sometimes described. The figure
below summarizes this:
The parameter C0 is the parallel capacitance of the crystal.
This is measured at low frequency with a device such as the AADE
LC Meter. This change is not a error
that needed fixing. However, I would recommend that anyone reading
this mark it in their copy and use the refined equation. It is typically
a 5 to 10% kind of refinement. (22may06) (15Nov07)
p3.21, middle col, 0.5 inch down from text top.
Replace "shape is severely distorted"
with " attenuation is markedly increased". (27July03)
p3.23, Fig. 3.44(C) The
vertical axis should not be dB, but ms for milliseconds. [That needs to be lower case ms
and not mS, which would be milli-Siemens, a unit of conductance
and not time. (corrected, 15Nov07)] (5Mar03)
p3.23, middle col, 3.6
inches down from top: replace "termina-tion"
with "termination" (24Feb03)
p3.23 and 3.24. On these pages we
describe the behavior of a "linear phase" crystal filter.
The use of the term linear phase is just an approximation
here. This filter was designed using the "linear phase
with equal ripple error" k and q tables from Zverev. These
tables are an approximation, as is often done in network
synthesis. (Indeed, the Chebyshev filter is an approximation
with ripples emulating a perfect brick wall filter.) Also,
the base filter is a low pass design. Here, it undergoes
a lowpass to narrow bandpass transformation when a practical
filter is designed. The approximations as well as the transformations
lead to departure from the ideal of a perfectly flat group
delay. (This is more of a comment than an actual errata
p3.24. Figures 3.46 and 3.47: Exchange
the two figures while leaving the captions in place.
That is, the Chebyshev filter is the one with a flat
passband response and severe "wings" on the group delay.
p3.24. Fig. 3.48 should be the
Fig 3.48 (same caption)
p3.24 left column, 0.6 inches
up from text bottom. Replace the text beginning with
"Fig 3.48" and ending in "5, and 10." with "Fig
3.48 is a special version with two equal resistors and a capacitor
that is A times the value of the first. Fig 3.49 shows representative
responses for R=10K, C=.01 uF, and A=1, 2, 5, and 10. " (10Apr04)
p3.24, middle column,
text up 3.5 inches from text bottom. Replace sentence
beginning with "For A<=2 and" with "For A=2 and
for equal R, the 3 dB cutoff frequency is given by" (10Apr04)
p3.24, middle column. Replace Eq 3.18 with
p3.24, middle column, text following Eq 3.18. Eliminate
from "where A is the capacitor ratio, C2/C1" to end of
paragraph. Replace with the following:
"For example, with R=10K-Ohm, C1=.01 uF,
C2=.02 uF, the cutoff is 1125 Hz. Eq 3.18 can be solved
for R for any cutoff or capacitor, but is restricted to A=2,
which is the Butterworth filter. (10Apr04)
p3.25, Fig 3.49. Add a sentence to the
caption: "The solid line corresponds to A=1 while highest peak
is for A=10." (27July03)
p3.26, Fig 3.53. Add a sentence
to the caption: "The solid line corresponds to A=1 while
highest peak is for A=10." (27July03)
p3.26, left column, line 2 down from text top.
Replace "ungrounded" with "grounded" (10Apr04)
p3.26, left column, line 3 down from text top.
Replace "grounded" with "ungrounded" (10Apr04)
p3.26, left column, 0.3 inch up from text bottom. Replace
"pure high" with "pure N=2 Butterworth" (10Apr04)
p3.26, middle column, replace Eq 3.23 with
p3.26, add text just below Eq 3.23.
"This is identical to Eq 3.18." (10Apr04)
p3.27, left col,
2nd line below equation 3.26. Text should
refer to Equation 3.25. (5Mar03)
p3.28, left col. 1.3 inches down from top of text:
"circ" should be "circuit" (24Feb03)
p3.28, left col. 4.2 inches down from top of text:
"generated" should be "generate" (24Feb03)
p3.28. Left column, 1.6 inches down from text
top. Says "all all".
Should read at all frequencies. (5Mar03, 10Apr09)
p3.30. Left column, 1.3 inches up from text
bottom. "It's" should be "its". (31July09)
p3.31, Fig 3.67. The
capacitors should be switched in the figure. The new figure is
p3.33, left column, 3.4
inches up from text bottom: Note the Greek mu followed
by i. The "i" should be a subscript, indicating that
this is an "initial" permeability. (9Dec03)
p3.34, middle column, 1.1 inches up from text bottom:
replace "later is -63" with "latter is -63"
p3.34, middle col. 2.7 and
3.5 inches down from top of text. Replaced
"powder" with "powdered" (24Feb03)
p3.36, left column,
0.7 inches up from text bottom: replace "while
Hybrid refers" to "while hybrid refers" (9Dec03)
p3.36, left col, 2.9 inches down from
top of text: add a hyphen to make text read "transformer-like" (24Feb03)
p3.38, Ref 4. The title
for the paper is "...Using Ultraspherical
p3.39, Ref 18. The complete reference is : B. Carver,
K6OLG, "High-Performance Crystal Filter Design," Communications
Quarterly, Winter, 1993. (27July03)