Kitted and Offered For Sale By The Four State QRP Group
If your receiver is plagued with 60/120 cycle buzzing in your shack or favorite portable QTH, the BUZZ-KILL will save your sanity.
From the creative mind of NMØS, the BUZZ-KILL is a special audio filter that removes 60 cycle noise and all of its harmonics, beating them down 40 db or more - it kills the buzz! If you have been suffering with bad line noise QRM, this add-on audio accessory will make ALL the difference in your rig's reception. Similar in concept to the Hi-Per-Mite, it is a drop-in AUDIO filter/AUDIO amp with configurable gain. This filter is unique - it is not a noise blanker. Instead, it has a notch at 60Hz and at _every_ harmonic of 60Hz, so it will completely null all the power line frequency hum and buzz that plagues the HF bands, it's just gone! ALL THROUGH HOLE parts ensure an easy build, there are NO SMT parts.
This is a compact, flexible design that can be used as a stand-alone outboard unit, or it can be easily integrated into an existing receiver
(see manual for details). It's onboard audio amp is capable of driving a speaker or headphones. Gain is constant from 100 Hz to 5kHz,
so it can be used with any CW, SSB or AM receiver.
Employ this filter and your 60 cycle woes will disappear!
A quantity discount is available for Club and Group builds, 5 kit minimum order required please.
Contact the kitter at the email address at the bottom of the page for more info.
Specifications and Design Features
Signal Gain: 0 dB or 20 dB, user selectable
Audio Power: 500 mW into 8 ohms, from 9v supply
Bandwidth: 100 Hz to 5 KHz, with notches every 60 Hz
Max Input Signal: 5.0v p/p
DC Power: 7 to 13 VDC at less than 75 mA
Altoids Compatible: Perfect for SOTA and /P operations.
Easy Build: Nice sized pads and traces make soldering easy. NO SMT parts.
NO Toroids: There are no toroids to wind.
PCB: High Quality, blue solder mask, two sided 2.6"x 1.7" printed circuit board
Parts List BOM
Part Layout Part location on board.
Photo Page Rig pix, part ID, and building tips.
Elecraft's Excellent Capacitor Identification Page Posted with permission.
Electronics 2000's Excellent Resistor Code Graphic Calculator Posted with permission.
The cost of this kit is $35 plus shipping which is included in the Paypal buttons.
If paying by check or money order (US dollars only)
please make it out to "Four State QRP Group" and send to:
Four State QRP Group
Tom Brown WØMFQ
PO Box 627
St. Charles, MO 63302
The BUZZ-KILL is carefully kitted and shipped by Keith Ford,
Please direct kit and part related questions to Keith
All proceeds are applied toward funding OzarkCon.   Thank you for supporting
The Four State QRP Group.