[CW] NM0S - HyperMite 200 Hz Audio Filter - NO RINGING!

[D.J.J. Ring, Jr.]

This looks like a good piece of kit, http://www.4sqrp.com/HiPerMite.php

Does anyone have one of these?

If so, do you like it?














































*HI-PER-MITEAn Active Audio CW FilterDesigned byDavid Cripe, NMØS[image:
JPEG Not Uploaded Yet]
<http://www.4sqrp.com/kits/filter/cwfilterdarpic2big.jpg>Click for larger
image.Kitted and Offered For Sale By The Four State QRP GroupThe
HI-PER-MITE is a HIgh-PERformance SMALL audio filter. It is designed to be
very versatile, have low parts count, be inexpensive, yet provide
outstanding performance. This is a flexible design that can be used as a
stand-alone unit driving headphones, earbuds, or speakers, or it can be
easily integrated into an existing receiver needing additional CW filtering
(see manual for details).Designed by David Cripe NMØS, it features a 200
cycle bandwidth with NO RINGING! It can be used as an external stand-alone
unit with an onboard audio amp for driving a speaker or headphones. It also
can be built into a receiver without using the audio amp, or with it if you
need an audio stage. This is a very useful accessory for direct conversion
or other rigs needing additional selectivity. It removes/reduces signals
and noise outside the 200HZ passband, and also power line hum in Direct
Conversion receivers. Thus providing comfortable listening while using
earbuds, headphones, or a speaker. If you have a direct conversion
receiver, you will love this filter.The HI-PER-MITE is a much improved
version of Dave's HI-PER Audio Filter circuit that was published in the May
1994 issue of 73 magazine. If you wish to learn more about the genesis of
the HI-PER Mite, and learn about important audio filter design parameters,
click on the original 73 article link in the documentation section
below.This low cost kit sacrifices nothing in the way of quality. It
features a high quality printed circuit board, low parts count, all through
hole parts, and fast and easy building. It is an excellent kit for first
time builders, and was chosen as the Buildathon kit for OzarkCon
2012. First time builders please note: This kit is not difficult to build,
there are NO SMT parts and the parts are wide spaced on the board making
installation easy.    Specifications and Design Features    Bandwidth:  200
cycles at the -3 DB bandwith points.    Center Frequency:  The center
frequency in the passband is 700 HZ    Signal Gain:  0 dB to 50 dB, user
selectable    No Ringing or Buzz:  Nice, smooth audio - care has been taken
in the design to eliminate ringing.    Versatile:  Drives speaker, earbuds,
or headphones. Use standalone or install inside rig.    Audio Power:  500
mW into 8 ohms, from 9v supply    DC Power:  5 to 13 VDC at less than 15
mA    NO SMT Parts:  All through hole parts..    NO Toroids:  There are no
toroids to wind, special circuits simulate them.    PCB:  High Quality,
silk screened, two sided 2.2"x1.5" printed circuit
board.    Documentation    Assembly Manual
<http://www.4sqrp.com/kits/filter/cwfiltermanual4.pdf>    Parts List
<http://www.4sqrp.com/kits/filter/cwfilterpartslist5.pdf>    Assembly
Manual in Spanish
<http://www.4sqrp.com/kits/filter/cwfiltermanual4_es.pdf> Translation by
Jon Iza EA2SN, thank you Jon.    Parts List in Spanish
<http://www.4sqrp.com/kits/filter/cwfilterpartslist4_es-1.pdf> Translation
by Jon Iza EA2SN, thank you Jon.    Assembly Manual in Portugese
<http://www.4sqrp.com/kits/filter/cwfiltermanual4_pt_br.pdf> Translation by
Ed Freitas PS7DX, thank you Ed.    Schematic
<http://www.4sqrp.com/kits/filter/cwfilterschematic3.gif>    Part Layout
<http://www.4sqrp.com/kits/filter/cwfilterpartslayout.pdf>    Want a
different center frequency? Here's How.
<http://www.4sqrp.com/kits/filter/cwfilter_f_vs_r_table_2.pdf>    Center
frequencies in Spanish
<http://www.4sqrp.com/kits/filter/cwfilterfreq_es.pdf> Translation by Jon
Iza EA2SN, thank you Jon.    Center frequency Calculator by Paul Jorgenson,
KE7HR.
<http://www.4sqrp.com/kits/filter/hpmfrequencycalculation.xls>    AA7EE
Dave Richard 's incorporation into a DC receiver.
<http://aa7ee.wordpress.com/2012/07/27/using-the-nm0s-hi-per-mite-filter-from-4sqrp-to-make-a-simple-40m-dc-cw-rx/>
 Posted
with permission, thanks Dave.    AA7EE Dave Richard's YouTube video of the
Hi-per-Mite in action. <http://www.youtube.com/watch?v=jc7e9VYgubk>  Posted
with permission, thanks Dave.    BX2ABT Hans Fong's You Tube Video Review
<http://www.youtube.com/watch?v=Pk_GFJsux24&feature=plcp> posted here with
permission.  Thanks Hans.    75 wpm dit performance by Chuck Vaughn, AAØHW
<http://www.4sqrp.com/kits/filter/cwfilter_75wpm_dit_performance.pdf> posted
here with permission.  Thanks Chuck.    Audio Bandpass Test by Chuck
Vaughn, AAØHW
<https://soundcloud.com/chaseology/hi-per-mite-audio-bandpass> This is an
audio file and a must listen,  Thanks Chuck.    K9PL's Review
<http://www.4sqrp.com/kits/filter/k9yatelegraphfeb2013hpm.pdf> in the K9YA
Telegraph  <http://k9ya.org/> (posted here with permission)  Thank you
Philip.    NMØS Original article in 73 Magazine
<http://www.archive.org/stream/73-magazine-1994-05/05_May_1994#page/n11/mode/2up>
 click
to turn the pages.    Photo Page
<http://www.4sqrp.com/kits/filter/cwfilterphotopage.html>    Electronics
2000's Excellent Capacitor Identification Page
<https://www.electronics2000.co.uk/calc/capacitor-code-calculator.php>
Posted with permission.    Electronics 2000's Excellent Resistor Code
Graphic Calculator
<http://www.electronics2000.co.uk/calc/resistor-code-calculator.php>
Posted with permission.*

73
DR
N1EA
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