"The RAS2 - A Remote Antenna Switch" by John Albert, WA9FVP, in the May 2024 issue, contains an error in Figure 4. The BC807 PNP transistors are incorrectly drawn as NPN devices. The emitters should be connected to +12V. A correction has been made to the digital edition. Also, good practice would include adding 1 K remisotors in the gate fee linies to each 2N7002, rather than have direct connections to the Arduino pins.

The article “Comparing Mobile/Portable Antennas of 20 Meters” by Ulrich Rohde, N1UL, published in the January 2020 QST contain a few typographical errors. The company name should be spelled Rohde & Schwarz in the caption of the lead image; the call sign mentioned on page 41 should be S51DX, and the author’s email address should have been listed as dr.ulrich.l.rohde@gmail.com.

In the article “An SWR-Shifting T” by Bill Conwell, K2PO, published in the February issue of QST, it should be noted that depending on the transmit power and capacitance value needed, there can be high circulating currents in the capacitor. The CDE catalog lists mica capacitor series and their continuous current versus capacitance value and frequency. Lower current capacitors can also be paralleled to increase the current rating.

Issue

Feedback

February

In the article “A Force-Sensing CW Paddle” by Art Heft, K8CIT, in the February 2019 QST, pins 2 and 3 of U1A and pins 5 and 6 of U1B should be swapped.

March

In the article “An Arduino-Powered RF Detector” by Teri Bloom, AC5YL, in the March 2019 QST, there are two errors in the schematic diagram shown in Figure 3. The Arduino Nano pin labeled “RAW” should have been labeled “Vin.” The cathode of diode D1 should be connected to the Vin pin, not the 5.5V pin.

The Hints & Hacks item "Upgrading an Analog Voltmeter” that appeared in the March issue of QST generated several questions to the author Dino Papas KL0S, specifically regarding the requirement to isolate from ground the VTVM’s 6.3 Vac transformer winding. The concern is that the additional inrush current may over stress the transformer’s capability and the article that Dino based his modification from specifically recommends doing this. 

In the article “Super Simple 6-Meter SDR Transceiver” by James Forkin, WA3TFS, the connections to pins 6 and 8 of U1 in the schematic diagram shown in Figure 1 should be swapped. The connections to Pin 8 should go to Pin 6 and vice versa.

In the article “A Portable End-Fed Half-Wave Antenna for 80 Meters” by Rick Littlefield, K1BQT, published in the March 2019 issue of QST, the second left-hand paragraph on page 33 refers to L1 as being wound on an “FT160-2” core. Instead, it is a T106-2 core as shown in the Figure 1 parts list.

April

In the article “State and Regional QSO Parties – Something for Everybody” by Hal Kennedy, N4GG, published in the April 2019 issue of QST, a photo caption states that the University of Michigan Amateur Radio Club was the winner of the 2014 Michigan QSO Party. This is incorrect. The Michigan State Amateur Radio Club was the winner of the Michigan QSO Party that year.

In the article “The Joy of Soldering” by Joseph L. Lynch, N6CL, published in the April 2019 issue of QST, an editor’s note at the end of the article states that lead/rosin core soldered has been outlawed and replaced by lead-free solder. This is inaccurate. While certain restrictions have been imposed in California, Europe, and other areas, the prohibition against lead solder in the United States applies only to its use in plumbing.

May

There are two errors in the parts list in the article "The Moxy Antenna" by Dave Ahlgren, K1BUK.

There are two 3-foot lenghs of ½ OD tubing to make the driven element, not one. There are also three 6-foot lengths of ½ OD tubing for the reflector and two directors, not one.

In the article "Identify and Track Down RFI," the author, Randy Standke, KQ6RS, describes how to locate interference using a loop antenna. W6HDG produced a video showing the author using the loop in this application. Click here to see the video.

July

In the article “The Vibro-Debugger” by Mike Bryce, WB8VGE, published in the July 2019 issue of QST, there is an error in the schematic diagram shown in Figure 1. The junction of resistors R6 and R8 should be connected to pin 5 (collector) of Q5, the 4N25 optocoupler, not base to pin 6, which should be left open.

September

In the article “A Slightly Off-Center-Fed Dipole” by Brian Machesney, K1LI/J75Y, published in the September issue of QST, the “Mismatch” heading in the fourth column of Table 1 should have been applied to the fifth column. The column labels should read, from left to right: Operating Frequency (MHz), Feed-Point SWR, Feed-Point Impedance (W), Line Loss (dB), Mismatch Line Loss (dB), and Total Line Loss (dB).

The article “Automatic Antenna Selection for a Remotely Controlled Station” by John Hill, W2HUV, that appeared in the November 2019 QST, contains three minor errors.

On page 35, directly following the subhead “LED Display,” the second sentence should read, “Install a 14-pin DIP socket at Z1(RA1) and solder it in place."

On page 36, the fourth sentence following the subhead “Antenna Controller” should read, “Cut a six-socket header in thirds to make three two-socket headers; another six-socket header in half to make two three-socket headers, and one of the three-socket headers in thirds to make three single-socket headers."

January

In the article “Testing the Eclipse’s Effect on 80 Meters with WSPR” by Barry Pfeil, K6RM, published in the January 2018 issue of QST, the arrow in the DXplorer graph on page 75 should be pointing to a sharp peak that occurred during the regular daytime lull between 1300 UTC on August 21 and 0100 UTC on August 22. In addition, it is important to emphasize that WSPR beacons on the HF bands must function with an operator in control, either on site or remotely, with the exception of beacons operating between 28.200 to 28.300 MHz.

 In the article "Digital Audio Oscillator," the Max294 (U3) is an analog device, not a digital device as stated in the article.

February

In "Live Trees Affect Antenna Performance," published in the February 2018 issue of QST, the Figure 5 ordinate label is incorrect. It should be "Front to back ratio, dB."

 In "An Audio Switching Unit," the labels for jacks J6 and J8 are reversed. On J8, change the words RADIO HP to RADIO MIC. On J6, change the words RADIO MIC to RADIO HP. 

May

In the article, "Build a 2-Meter Quadrifilar Helix Antenna" by David P. Finell, N7LRY,  Step 4 should read, "Drill or punch four 1⁄4” holes evenly spaced at 90 degrees to each other around the 2” PVC coupler 1⁄4 the distance from one lip and on the same plane. When the 2” coupling and the 1” cap are oriented centered and on the same axis the holes in both should align."

The author adds that the antenna can be mounted by feeding the phasing network assembly into a length of PVC and glue the PVC to the bottom of the antenna.  The antenna can then be mounted like many other vertical antennas with U bolts to a mast or other vertical structure

June

In the article, “A Stacked, 16-Element Collinear Array for 6 Meters” by Paul Kiesel, K7CW, in the June 2018 issue of QST, the wall thickness of the 3/8-inch tubing (.375-inch) should be 0.028-inches, not 0.28-inches as shown in the article.

In the article “A Two-Element Wire Beam Antenna for 20 Meters,” pp 30-31, the author identified the wire used as insulated #14 AWG THWN copper wire. The dimensions in Table 1, however, are those for bare #14 AWG wire, which can be used. If it is desired to use the specified THWN wire, the wire lengths A and C in the table, should be reduced by 2% (multiply by 0.98).

In “Hints and Hacks” in the December 2018 issue of QST, Paul Dobosz, K8PD, described a circuit to allow the use of dynamic microphones with transceivers that require electret microphones. The schematic diagram in Figure 3 omits a resistor that needs to be included in series with the collector of the transistor (Q1) prior to the junction of R1 and C2.  Adding a 1.2 or 1.8 kΩ resistor in series replicates the power supply impedance the preamp was designed for. In addition, the captions of Figures 2 and 3 captions make reference to “phantom power.” The correct terminology is "plug-in power."

January

In Figure 3 of the January 2017 "Hands-On Radio" column, the traces are mislabeled. The blue trace should be labeled Insertion Loss (S21) and the red trace should be labeled Return Loss (S11).

 February

In the article “Get Ready for the Solar Minimum” by Steve Ford, WB8IMY, published in the February 2017 issue of QST, the length of the inverted L antenna shown in Figure 2 should have been labeled as 130 feet.

In “A Panadapter for your Transceiver or Receiver” by Jim Kocsis, WA9PYH, published in the February 2017 issue of QST, the URL shown on page 35 (in the last paragraph of the third column) should be: hdsdr.de/RTLSDR_with_HDSDR.pdf.

 March

In the article, “Tri-Band Antenna without Radials for 2 Meters, 1.25 Meters, and 70 Centimeters," by Edison Fong, WB6IQN and Tessa Fong, KJ6QXM, published in the March 2017 issue of QST, page 35, an arrow should point from the notation "RG-174A coaxial cable" to the gray coaxial cable inside the lower helix, and a connection should be added between the shield of the coax and the ground side of the SO-239 connector. Click here to download a copy of the corrected drawing.

In “Hands-On Radio” by H. Ward Silver, N0AX, published in the March 2017 issue of QST, the equation e = 4kTRB should have had a square root over the right-hand side. Converting e to power should be shown as e/4R (instead of e/R) as well. The correct name of the constant k is just Boltzmann's constant, not the related Stefan-Boltzmann's constant. The temperature conversion should show 290°K = 16.9°C = 62.6°F.

 April

Concerning the article “A Bluetooth Interface for Fldigi” by Jim Cook, W8WKE, publishing in the April 2017 issue of QST, the interface will not function with Fldigi versions 4.0.2, 4.0.3 and 4.0.4. The sound card interface software was changed in version 4.0.2 and was fixed in version 4.0.5. A new setting was added to the audio devices configuration screen “Device supports full duplex” and it must be unchecked for the interface to work.

October

In the article “Understanding Propagation with JT65, JT9, and FT8” by Carl Luetzelschwab, K9LA, published in the October 2017 QST, all references to a quiet rural noise environment should be to a residential noise environment instead. Also, in Figure 5, the Y axis should be labeled SNR (dB) and the -15 label should be -10.

In the “Done In One: Battery Back Up For Your Wall Wart” by Paul Danzer, N1II, in the January 2016 QST, the mechanical drawing of Q1, a P-channel MOSFET shows connections that may be unique to some RadioShack parts. Other sources for this part may use different connections for the gate (G), source (S) and drain (D). For example, if Q1 is purchased from a different source, the pinout diagram would be effectively reversed. D could be the middle pin and S the one on the right. It would be best to verify these connections for the part you buy.

In the same article, the positive and negative designations of pins 1 and 2 of the 741 op-amp shown in Figure 1 are backward. The correct label should be pin 2 (negative) and pin 3 (positive). The circuit functions properly as shown, however.

In the article “Desk Microphone Power-On and PTT Indicators” by Don Dorward, VA3DDN, in the January 2016 QST, LED1 in Figure 1 is reversed. The green cathode should connect to point Kg while the red cathode should connect to Kr.

Also, in the list of parts for Q1 and Q2, there are 4 different common transistor types as being suitable for use. However, the BC547B transistor pin-out is 180 degrees reversed from the silk-screen outline on the pcb. This applies to the 2N2222 as well. The silk-screen outline on the pcb matches the 2N4401 and 2N3904.

In “Meter Bands and Megahertz – Why We Use Both” by John Stanley, K4ERO, in the February issue of QST, Table 1 shows 0.400 – 0.410 as having a wavelength of 0.7477 – 0.7496 meters. The frequency should have been listed as 400 to 401 MHz. The comment about this being close to our present 472 to 479 kHz allocation should instead have mentioned our present 420 to 450 MHz band. Finally, in Table 2, the label at the top of the left-hand column should have read “Band, Meters.”

In the article “Understanding Controlled Envelope Single Sideband” by Dave Hershberger, W9GR, published in the February 2016 issue of QST, the axes in Figures 9, 10, and 13 are mislabeled. For each of these three figures, the top of the left hand vertical axis should be labeled 1.6.

In the article "Can Solar Power and Ham Radio Coexist?" by Tony Brock-Fisher, K1KP, published in the April 2016 QST, the first line of the second paragraph should read "A typical home consuming 720 kWh per month would need an average of about 1 kW continuously delivered to the home." In the original text, kW appeared rather than kWh.

In the “Doctor is In” column, July 2016 QST, p 53, Figure 1 has the incorrect pin designations shown. The correct RS-232 9-pin assignments are as follows:

Pin       Signal Name

1          Data Carrier Detect (DCD)

2          Receive Data (RD)

3          Transmit Data (TD)

4          Data Terminal Ready (DTR)

5          Signal Ground (SG)

6          Data Set Ready (DSR)

7          Ready to Send (RTS)

8          Clear to Send (CTS)

9          Ring Indicator (RI)

 In the article “Measure Inductance with a Digital Volt Meter” by Paul Danzer, N1II, in the November 2016 issue of QST, there is a footnote on page 37 that references an “Inductance Adapter” kit being offered by Rainbow Kits. Unfortunately, Rainbow Kits discontinued the product just after the November QST went to press.

In the article “A Long-wave Upconverter” by Fred Brown, W6HPH, published in the December 2016 issue of QST, there is a mention on page 38 of R2 being the balance control. That is incorrect. The balance control is R12.

In the December 2016 article "Safety First! - Part 2 - Grounding”, Wayne Eckert, WT4FEC, notes some clarifications and supplements to Figure 1 are needed. First, any clamp used for grounding should be a mechanically appropriate type rated for that use. You can find them in the electrical section of hardware and home improvement stores or from local electrical supply houses. The clamp should also be of the right material to avoid corrosion from direct contact between dissimilar metals. For example, recognizing the difficulties of connecting galvanized towers to copper ground systems, Rohn now offers the R-CPC1/1.25 Tower Base Ground Clamp (http://www.3starinc.com) that will not result in corrosion. Stainless steel shim between a bronze clamp and galvanized steel has also been used for this purpose. Finally, if it is practical to do so, curve or sweep grounding conductors toward the earth connection as the connection to the ground system is made. This results in a lower impedance connection. These practices are covered by the NEC Articles on grounding (www.nfpa.org/codes-and-standards/resources/free-access) and are described in detail in the NEC Handbooks, which are available from your local library.

Several minor errors occurred in “An Easy WSPR 30 Meter Transmitter” by George Steber, WB9LVI, that appeared in the January 2015 issue of QST. Although the parts list descriptions of L5 and L6 are correct in Figure 2, the text on the same page mistakenly states: “For L4 wind 13 turns on a T37-6 core" and “For L5 wind 17 turns on a T37-6 core." The text should have read: “For L5 wind 13 turns on T37-6 core" and “For L6 wind 17 turns on T37-6 core" respectively. In addition, Test Point label TP3 is missing from the Figure 2 schematic. It is located at output of J2 and the top of C2. The 12 Vdc label is missing from schematic as well. It is located after diode D1, on the cathode side. Finally, labels for drain (D), source (S) and gate (G) are missing from Q2 and Q3 from the Figure 2 schematic.

In “A Solid State 1.25 kW Linear Amplifier” by Andrew J. Buckler, K2OP, that appeared in the January 2015 QST, there is an error in the diagram of the HF+Six amplifier deck (Figure 3). The anode of the Zener diode should be grounded, as should the adjacent 22 pF capacitor, 150 Ω resistor and the bottom of the primary winding of T1.

In “Untangling Digital Voice Above 50 MHz” by Bob DeMattia, K1IW, published in the April 2015 QST, the article implies that all NXDN, P25 and DMR transceivers are digital only, single band and not front panel programmable. This is inaccurate. There are a number of models for each mode that are multiband, analog compatible and front panel programmable.

A few errors crept into the article “Don’t Blow Up Your Balun” by R. Dean Straw, N6BV, published in the June 2015 issue of QST. On page 32, in the fourth line from bottom of column three, “435.8 -j326.7" should have read “435.8 -j1326.7.” On page 33, in the first column, second paragraph from the bottom, “435.8 - j 326.7" should have read "435.8 - j1326.7." Finally, in Figure 10, the red label at the top right should be "1027 W to antenna at 14.1 MHz."

In “Repair and Restore Your Mosley Beam” by Dick Sander, K5QY, published in the July 2015 issue of QST, the author's website URL is shown incorrectly. It should be: www.k5qy.net.

In the October 2015 “Doctor is In” column (pp 55-56), there is a serious computational error in the presentation of the antenna shortening by the use of a shunt inductor as shown in Figure 1. Bill Wortman, N6MW, author of an excellent QST article on the “hairpin” match (June 2013, pp 30-33) noticed a problem with my analysis. The center inductor should have acted in a similar fashion to a hairpin, with the result that the impedance would be raised significantly, in this case to tens of thousands of ohms. The problem was that I neglected to change the EZNEC model of the inductor exterior connections from series to parallel — my apologies for any confusion or consternation. The use of a shunt inductor (or hairpin) is only appropriate for antennas that are much closer to resonance. The shortening techniques shown in Figures 3 and 5 should be correct as presented. -- Joel Hallas, W1ZR

In “Antenna Gain, Part I: What Do Antenna Gain Numbers Really Mean?” QST, November 2015, pp 42 – 44, the caption for Figure 1 has an error. It should have said, the peak gain is 2.13 dB with reference to an isotropic antenna or 2.13 dBi.

Mike Aiello, N2HTT, the author of the "Digital Fist Recorder" offers the following advice . . .

 1. The sketch as downloaded is set up to work with an external keyer, so it holds the TX line  high, and drops it low to key the rig. If you wish to key the rig using a optocoupler or a transistor switch, the TX line should idle low, and be raised high to key. This is configured in line 142 of the main sketch. To idle the pin high, no change is needed:

DigitalOutputPin KeyingOutput( KEYING_OUTPUT_PIN

,DIGITAL_PIN_INIT_STATE_HIGH

,DIGITAL_PIN_INVERTING);

 To idle the pin low, change the declaration to read:

 DigitalOutputPin KeyingOutput( KEYING_OUTPUT_PIN

,DIGITAL_PIN_INIT_STATE_LOW); 

2. A few hams have reported problems with recordings that have clipped beginnings, or do not reproduce the keying correctly. These have been traced to the SD card, and have been corrected either by formatting the SD card again, or switching to a faster one. If you run into difficulties of this nature, try switching SD cards.

● There are several corrections to the parts list shown in “A 10 Meter Beacon Transmitter” by Lou Burke, W7JI, in the February 2014 QST, page 33. T1 should be 12 Turns of #22 AWG wire on a T50-6 core; T2 should be 13 turns of #22 AWG wire on FT50-43 toroid; T3 should be 4 turns of #22 wire bifilar on T50-43 core and there is only one heat sink required for the driver (not two).

● In the article “Designing a Shortened Vertical for 75 and 160 Meters” by Christoph Kunze, DK6ED, published in the March 2014 issue of QST (page 30), the Figure 3 caption should have read, “Current distribution in a shortened vertical antenna with a base loading coil (at A) versus a shortened vertical with a capacitance hat (at B)." Also, the illustration in Figure 1 should have indicated that the height limit for the blue pattern was 52 feet (not 25 feet).

In “A Tube-Based Bench Supply for Tube Projects” by Bryant Julstrom, KC0ZNG, that appeared in the August 2014 issue of QST, the label for resistor R11 is shown in the Figure 2 schematic diagram, but not the schematic symbol for the resistor. The symbol should appear next to the label between R12 and the junction of the common pole of switch S3 and the +HV output. Also, vacuum tube V2 is correctly labeled as a 12AU6 in the schematic diagram, but is incorrectly listed as a 12AV6 in the Figure 2 parts list.

In the article “Antenna Masts: Safety and Selection” by Don Daso, K4ZA, in the September 2014 QST (page 30), there is a statement that DX Engineering offers software to calculate stress on masts. This is inaccurate. The DX Engineering Mast Load Estimator is an on-line calculator that allows the user to model an installation to determine which of the two mast sizes sold by DX Engineering is adequate for the proposed installation. It is specific to only those two masts. There is also DX Engineering mechanical calculation software (YagiMechanical) available, but it does not calculate mass stress.

In the article "A New Life for an SB-610 Monitor Scope" by Dave Cook, WA0TTN (page 37), we neglected to include an updated author biography with the address to his web site for more information. You can find his web site at www.netdave.com/wa0ttn.

A few errors crept into the “Hands On Radio” column by Ward Silver, N0AX, in the October 2014 QST. In Figure 3, the + and - inputs to the input amplifier are reversed. "Input" should connect to pin 2 (the non-inverting input) and "V_REF" through R1 to pin 3 (the inverting input).  This will result in the output of U1A being zero when Input and V_REF are equal. V_REF and Input must both be ground-referenced. In addition, pin 4 of U1 should be connected to V- (a negative voltage) and not ground as shown. The supply should be at least ± 6 V as indicated in the text.

Ralph Crumrine, N0KC, author of “A 1500 W Centennial Amplifier for the 80 – 6 Meter Bands,” published in the December 2014 issue of QST (page 30), advises that two versions exist of the Ohmite Model 111 tap switch used for the band selector switch, S301A. Old stock might be ceramic; new stock will be plastic. The ceramic bodied part must be used.  The Model 212 switch is ceramic only and might be a useful substitute.

In "Transceiver Power Control Accessory" by Phil Salas, AD5X, in the second paragraph on page 38 the author states: "With S1 set to NORM, the voltage at ALC XCVR and ALC AMP should vary . . ".

The sentence should have read: "With S1 set to NORM, the voltage at ALC XCVR should vary . . ."

You can't measure voltage at ALC AMP because that is after a reverse-biased diode.

● In “Hands-On Radio” [Jan 2013, pp 63-64] the output connection in Figure 3 (B) should be to the normally open (N.O.) relay contact.

● In “Down Periscope” [Jan 2013, pp 36-38] The galvanized steel pipe identified in the “Mounting Arrangement” section should be 1 1/4 inch, not 1 1/2 inch diameter.

● In “A Sampling Down Converter for Low Frequency Oscilloscopes” [Jan 2013, pp 39-45] the description of L1 in Figure 2 is incorrect. Please use the description in the parts list instead. In Figure 3, the INPUT and OUTPUT terminals of U7 are shown reversed.

● In “A Three to One Dummy Load” [Feb 2013, pp 30-32] there is an inconsistency between the wiring of R6-R9 in Figure 1 and the text. The text describes them interconnected at the intermediate point (bottom of R6 to bottom of R8), while the schematic doesn’t show the connection. Either arrangement will provide the desired 1:1 SWR.

In “The Penticton Solar Flux Receiver” [Feb 2013, pp 39-47] the lead map incorrectly shows Lake Sakakawea in Montana. It should have been shown in North Dakota.

●In Figure 3 the block labeled “2.75-2.85 GHz Band-pass Filter” in both the A1 and B1 paths should read “GasFET Amplifier.”

●In “Digital Detective” [Feb 2013, p 80] in the digital edition of QST, the link www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=8861 text is correct but the link address is not. When selecting the link, change “8661” to “8861” and you will be able to access the correct web page.

● In Figure 1 of “An MCW Keyer for V/UHF FM” [Apr 2013, pp 37-38], Q1, Q2, Q4 and Q5 are misidentified as PNP transistors. They are actually NPN types. The base diagram for the Q3 is correct as shown, just its label has a typo.

● In “Overvoltage Protection for ac Generators” [Apr 2013, pp 43-46], some of the identified parts are no longer available, or are not available in single unit quantities. Please make the following changes:

C1 — 220 µF, 35 V electrolytic capacitor (Digikey P5166-ND).

DS1, DS7 — Red LED (Digikey 751-1129-ND).

DS3-DS5 — Green LED (Digikey 751-1099-ND).

DS2, DS6 — Yellow LED (Digikey 751-1144-ND).

The original amber LED is no longer available in 3 mm size so that has been changed to yellow.

●In “Overvoltage Protection for ac Generators” [Apr 2013, pp 43-46], the author provided the following update: If you are using the circuit board from Far Circuits, note that they have included the two jumpers I discussed as connection on the board. Thus, you will not be able to use the on-board jumpers as part of the calibration process. Instead, you will have to carefully touch your positive voltmeter probe to the LM-3914-1 pins. The negative lead attaches to the negative foil strip on the bottom of the board where the negative lead of capacitor C1 is attached.

LM-3914-1 pin 6 is for the lower voltage setting (0.35 V dc) and pin 4 is for the higher voltage setting (0.55 V dc). Remember, those are starting voltages and will have to be adjusted a little.

Remember, while making adjustments, avoid contact the leads going to the GFCI and with R5 and U3, including the foil side of the board around those components.

• In "Remote Control of Accessories via the Internet" [April 2013, p 31] in the Figure 1 parts list, the K1-K8 SPDT relays should be identified as Digikey part 225-2077-ND or Mouser part 769-JQ1P-12V-F. These are only examples of relays that can be used in this project.  Relays should be selected based on the ac or dc voltages and currents required by the devices being switched

• In “Build a Linear 2 Meter 80 W All Mode Amplifier,” by James Klitzing, W6PL [May 2013, p 30-34], two heat sinks are included in the parts list, but only one is necessary, specifically: Heat sink extrusion 5.375 x 8 x 1.375 inches (Heat Sink USA A008).

• In “Up Front” [June 2013, page 20], the photo at the upper left corner of the page with the caption "On the road with the tower trailer" is actually a photo of different tower trailer that the author built in the 1970s and towed from California to Vermont. It is not the same trailer shown in the rest of the article.

In “The Real Q-Pole” [July 2013, pp 37-38] the spacing between the rods of the Q section is 2 3/4 inches measured at the outer edges of the two elbows, not 1 1/2 inches as shown in the diagram.  This is not an electrically critical dimension, but should be noted.

• “Hands-On Radio” column #127 [August 2013, pp 53-54] mistakenly uses 1.866 for the square root of 3 when the correct value is 1.732. The correct voltage between two phases of a three-phase 120-V system is then 120 x 1.732 = 208 V.  Two hundred and forty volts would be supplied in a split-phase system with each phase supplying 120 V.

 In “Level Converter to Allow Full Control of Peripherals by Computer or Radio” [pp 38-40] the ground connection on J4 should go to pin 5, not pin 4. Also the "Hamspeak" item was in error. It should have read:

Null Modem -- An adapter to interconnect two devices both wired as EIA RS-232-C DCEs or DTEs using DSUB25 or DSUB9 connectors. To allow communication, interconnect RECEIVE DATA (pin 3) on one connector to TRANSMIT DATA (pin 2) on the other for either connector type. The SYSTEM GROUND connection should also be interconnected end to end -- pin 7 on DSUB25, pin 5 on DSUB9.

For most devices that require flow control, cross connecting CLEAR TO SEND and REQUEST TO SEND either at each connector, or from end to end, will allow data flow. Some implementations may also require DATA SET READY and CARRIER DETECT at one end connected to DATA TERMINAL READY at the other.

In “The 43 Foot Vertical — What’s the Magic,” June 2012, pp 30-31, I was remiss in not mentioning that the 43 foot vertical, as any monopole fed against ground, requires a good radial ground system to be efficient. The radials can be on or under the ground, or can be elevated. If you’re not familiar with the requirements for such a system, please look over the excellent QST article by Rudy Severns, N6LF, on the subject.¹— J. R. Hallas, W1ZR, Technical Editor, QST.

 ¹R. Severns, N6LF, “An Experimental Look at Ground Systems for HF Verticals,” QST, Mar 2010, pp 30-33.

In “A Digital Interface for Fldigi” [Aug 2012, pp 36-38] Figure 1 shows the connectivity of the output pins of U2 in error. Pin 4 should go to MIC GROUND, pin 5 should go to PTT and pin 6 should be left unconnected.

The miniature audio isolation transformers, T1-T3, are no longer listed by RadioShack. Rick, WA6NUT, suggests the Triad TY-145P as a suitable replacement. It is available from the usual suppliers, including Jameco (www.jameco.com)and Mouser (www.mouser.com).

In “The Uncooperative Tree” [Sep 2012, p 30-32] the value of the inductors in Figure 2 should have been shown as 33 μH.

In “Power Carts for Scouts and Field Operations” [Sep 2012, pp 36-40] switch S3 in Figure 6, shown as a DPDT center-off switch, could be a SPDT center-off unit instead.

In “The Evolution of DX Spotting” [Oct 2012, pp 71-72] the author noted that he used the work “splitter” when he meant “skimmer” when describing certain terminology related to the Reverse Beacon Network.

● In “Boat Anchor Buddy” [Nov 2012, pp 53-56] there should have been a footnote indicating that PC board files and other layout information is available on the QST in Depth website.

● In “Boat Anchor Buddy” [Nov 2012, pp 53-56] the parts list in the caption of Figure 1 has the values of C5 and C6 reversed, they are shown correctly in the schematic. R11 is missing from the parts list and is a 6800 ohm resistor like R13. In Figure 1, Q7 has the collector and emitter leads reversed. The board layout is correct.

● In “Boat Anchor Buddy” [Nov 2012, pp 53-56] some builders have experienced excess current and heat in the NE555 timer IC. Lower current operation will be achieved by removing R6 from the + 12 V line and inserting it between pin 3 of U1 and the base of Q4. A revised layout drawing is on the QST-in-Depth website at www.arrl.org/qst-in-depth.

● In “Building Inexpensive HF Power Attenuators” [Nov 2012, pp 32-33] the first formula on page 32 should indicate 1.41 A, not 0.71 A.

● In “Have Fun Building the Simplest Transmitter” [Nov 2012, pp 46-49] the author has provided some additional coil data. He notes that his 40 meter L3 is five turns, wound exactly as L2 and that he uses his 40 meter L2 as his 80 meter L3.  The value of R1 is not shown. The correct value is 100 kohms, 1 W.

In the “Power Supply Options” sidebar C1 and C2 are 8 μF, 450 V electrolytic capacitors. They are available from Antique Electronics Supply (www.tubesandmore.com), part number C-SA8-450.

● The author of “Distracted Driving and Amateur Radio—A Civil (Law) Perspective” [Nov 2012, pp 81-82] has sent us an update regarding his article. The article includes the statement: “In Illinois, an effort by ARRL officials quickly convinced the legislature to adopt a blanket exemption for Amateur Radio from the measures being considered.” The final legislation (Public Act 97-828) that was adopted does not appear to contain the blanket exemption for Amateur Radio. The blanket exemption has been amended onto another bill that remains in committee and is unlikely to be passed this session but could be reintroduced next year.

● In “PSK-31 Operation on 2 Meter FM” [Dec 2012, pp 37-38] in Figure 1, the word “Ring” should be further to the right to line up with the contact for the right channel. The portion of the connector on the far left is the “sleeve.” In addition, the tip should be shown to the right of the ring.

● In “Product Review—Elecraft KX3 HF and 6 Meter QRP Transceiver” [Dec 2012, pp 39-44] the last word of the first paragraph under What’s In The Box on page 39 should be “translator,” not “transistor.”

● In “Life Members Elected” [Dec 2012, p 60] Brad R. Woodward, KG4FUS, was included in the list in error.