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The ARRL RFI Book -- Second Edition. Practical Cures for Radio Frequency Interference.

Transmitter Hunting -- Radio Direction Finding Simplified

AC Power Interference Handbook -- New insights into the causes, effects, locating and correction of power-line and electrical interference. 3rd Edition.

The RSGB Guide to EMC -- Tackle RF interference problems and understand the underlying causes.

March 2006 QST Feedback

In "Laptop Battery Modification" [Hints and Kinks, Nov 2005, p 72 and Jan 2006, p 64], the value of C1 should be 6800 µF, as correctly noted in the parts list.

In "A Short History of Radio Transmitters" [Jan 2006, pp 40-43], Figures 2 and 4 have an extraneous short across the gaps. In addition, an earth ground should be shown for each transmitter as a part of the antenna system. The corrected figures are shown in www.arrl.org/files/qst-binaries/feedback0306.zip.

In "Smaller Loop Tuner from MFJ" [New Products, Jan 2006, p 62], MFJ has confirmed that the tuner's power rating has been changed to 50 W.

In "Bridges -- A Doorway to Modern Electronics" [Technical Correspondence, Nov 2005, p 79], the text reference for footnote 1 should be at the end of the third full paragraph in column 3. The heading "Conversions*W*" should be just "Conversions." In the second paragraph of the Half Lattice section, "M2" should be "R2."

In "Technical Correspondence" [Jan 2006, p 73], Note 1 should be referenced at the end of the sixth paragraph in the first column. Figure 2C has the polarity signs at the input to the operational amplifier reversed. Figure 4D is incorrect as drawn. The corrected figure is shown in www.arrl.org/files/qst-binaries/feedback0306.zip.

In "A Sound Card Multimode Controller Switch" [Jan 2006], the drawing of Q1 (4N35) in Figure 1 on page 60 is shown upside down; the arrows are both pointing in the wrong direction. The pin numbers are shown correctly, however. In addition, subsequent to publication it was found that while the value specified for R3 worked for some radios, others required a lower value for proper keying. Details can be found in www.arrl.org/files/qst-binaries/feedback0306.zip.

In "VocalMaster -- A Speech Processor for Low Power Operators" [Jan 2006, pp 31-35], Figure 2 shows diodes D7 and D8 as 1N4148. They should be 1N4001 as shown correctly in the parts list.

Clarification: "Elevation Angle Measurements During a Local Contest" [Jan 2006, pp 28-30] was published earlier in very similar form in RadCom. In addition, "The HyGain DX-88 Vertical, Refined" [Feb 2006, pp 36-38] was published previously in German in Funkamateur.

In "A New England Treasure" [Up Front in QST, Jan 2006, p 21], the name of Robert W. Merriam, W1NTE, was misspelled.



Page last modified: 09:10 AM, 06 Mar 2006 ET
Page author: qst@arrl.org
Copyright © 2006, American Radio Relay League, Inc. All Rights Reserved.