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In “Product Review -- Yaesu FT-450 HF and 6 Meter Transceiver” [Dec 2007, pp 53-37], the Key Measurements Summary graphic has the 3rd-Order Intercept taken at the wrong level. The correct values at 20 kHz spacing are 17/17 dB. The 2 kHz bar should be –11 dB.
In “The Handy Yagi” [Nov 2007, pp 37-38], we left out the lengths of the Yagi elements. The correct lengths are shown in the following table.
Table
1
Handy Yagi Dimensions (inches)
Element |
Spacing |
Cumul |
Length |
Half-length |
DE |
|
|
12.88 |
6.44 |
D1 |
5.25 |
5.25 |
11.75 |
5.88 |
D2 |
11.0 |
16.25 |
11.69 |
5.84 |
D3 |
5.88 |
22.13 |
11.63 |
5.81 |
D4 |
5.75 |
27.88 |
11.56 |
5.78 |
D5 |
5.75 |
33.63 |
11.50 |
5.75 |
In “A Computer Interface for CW” [Dec 2007, pp 46-47], there were two errors. The value of R3 in the parts list should be 10 W as shown correctly in the schematic. The wiring of switch S1 is incorrect in the schematic; it should be wired as shown in Figure 1.
In “Simple Sideband, Another Approach” [Nov 2007, pp 39-44], there were a number of errors and updates. All text references to the J-176 P-Channel FET switch in Figure 1 should be to “Q8” rather than “Q9.” Q8 is incorrectly drawn in Figure 1 as an N-channel rather than a P-channel FET. The picture caption on page 39 should identify the rig on the right as having the FreqMite counter from Small Wonder Labs. On page 41, second column, the “signal-isolating transformer T3” text should also include transformer T4. In Figure 3, a connection dot is missing between relay K1 and a common node of R1, D3 and C1. Transmit channel gain can be further controlled by replacing resistor R12 with a 100 Ω trimpot in the emitter circuit of Q3 in Figure 3. Wayne McFee, NB6M, and the NORCAL QRP Club deserve credit for popularizing the soda straw PTO. There are several extraneous references in the text to “FN-6” (page 39, column 2, second paragraph) and “FN-5” (page 43, column 2, third paragraph) that should be disregarded.
