YO Changes 7.01 YO looks for YO.INI and YO.SET in the directory of YO7.EXE. dBdi works, boom insulation correctly saved, and other bugs fixed. Math library updated. 7.02 YO.SET not required. FOM coefficients changed. TEMP used for NEC in and out files and npout. 7.03 \ not needed after TEMP. Reflector position fixed by default. 7.04 Perfect match becomes ideal match. Dot-matrix bugs fixed. 7.05 Spacing and margins changed for printed Yagi files. Optimizer code rewritten. TEMP bug in Windows NT fixed. 7.06 TEMP bug from 7.05 fixed in NY. Fixed and rounding notation changed in Elements menu. I works during graph overlay and grayed in graphs help. 7.07 Yagis per second displayed. Faster pattern calculation and plotting. Undefined TEMP is valid. 7.08 Mouse limits correct after plot. 20 kb less memory needed. Faster local optimization and watch mode. Faster ARRL log-dB calculation for pattern sketches. Boom diameter not lost when file saved with untapered output. Del and ^Del swapped and ^Ins added. MINSP observed for Ins or ^Ins. Notepad bug fixed and code cleaned up. 7.09 Five analysis freqs for YO-Pro. Saved graph restored after NEC. Upper-case W, X, Y accepted during optimization. 80-bit precision for intermediate variables in matrix solution. Optimization bug fixed for nonvariable KLM DE spacing. 7.10 Triangle cannot be overwritten after graphs or plot. 7.11 Linear polar scale for YO-Pro only. Some variables and constants made double precision. 7.12 YO-Amateur restricted to 50 elements (YO-Pro remains 70). KLM phasing-line velocity factor added to Match menu and Yagi file. Random deviations specified in Tradeoffs menu instead of YO.SET. Double-precision dB conversion. Bug when adding end director fixed. 32-bit number of restarts. Lockups for extremely low impedances prevented. Optimizer refurbished. Error handling improved. 7.13 Optimizer code tightened. Minor bugs fixed. Fixed/nonfixed boom length instead of allow longer boom. 7.14 Lockup prevented for elements spaced < MINSP. Zinc written/detected as resistivity for compatibility with old versions. SWR curves for ideal match automatically refined; I function deleted. Selected directory does not appear in directory list on file screen. Fixed dimensions persist after element insertion and deletion. SWR curve rescaled after SWR refined. KLM gradient bug fixed. 7.15 Accuracy improved for balun-lead inductance calculation. Balun-lead diameter can be specified. Wire gauge can be entered with # symbol. 7.16 Untapered/boomless output restricted to AO output files. 7.17 Wild-Z optimization termination check ignores temporary glitches. Maximum element length correct after element insertion or deletion. 7.18 Invoking the Match menu with Alt-M uses NEC input-impedance values. Untapered AO-output and rounding code simplified. 7.19 YO/NEC comparison not lost after certain menu functions. PCX filename correct after invoking NEC. 7.20 VGA code and math library updated. 7.21 Protection added for video BIOSes that trash registers. Minor display bug fixed. 7.22 Additional Pentium optimization yields slightly faster execution. NEC uses extended memory instead of hard disk for large models. Mouse doesn't jump on first movement. Color PCX files generated. 7.23 Internal changes, 1% faster execution. 7.24 Local optimizer fine-tuned to dig deeper. Minor cosmetic changes. 7.25 General bracket of arbitrary geometry added to mounting-bracket models. 7.26 Slightly faster execution for YO7.EXE and NEC-2.EXE. Better optimization when elements are at minimum spacing. Position deviation defaults to 20%. 7.50 Frequency weighting added to help flatten performance across a passband. Good-enough soft-limiting revised to let the optimizer dig much deeper. Trials with extreme element lengths rejected to speed global optimizer. Fletcher-Reeves and Polak-Ribiere optimization methods recombined. Ideal-match SWR not refined for graphs of spot-frequency designs. Optimization bug in 7.26 for nonvariable KLM DE spacing fixed. Accuracy slightly improved for 5° patterns and F/R. No traces dotted for PCX output of high-resolution plot. Model blow-up can't corrupt subsequent calculations. Bug fixed for output files with wavelength units. VBE file-screen message more informative. Graph resolution defaults to two pixels. 7.51 Slightly faster execution. 7.52 Bug fixed for F/R region forward of 90°. 7.53 Slightly more accurate YO and NEC constants. Faster screen capture for PrtSc. Typematic control removed. Refined graphs grid. Smaller YO7.EXE. 7.54 Series reactor replaces ideal match series reactance. Minor cosmetic changes and code-efficiency improvements. 7.55 Ideal match yields lower SWR. 7.56 Optimizer tweaked for better convergence. 7.57 Tabbing through matches does not alter match dimensions. 7.58 KLM optimization bugs fixed. KLM impedance accuracy improved. Path not required to specify subdirectory of current directory at Other. 7.59 YO and NEC account for mismatch loss for receiving antennas. 7.60 YO PLOT bugs fixed for asymmetrical patterns generated by AO. 7.61 All gain figures, including plot annotation, include mismatch loss. Cosmetic refinements for overlay plots and AO plots. Folded dipole rod length tracks single-taper driven element length. Optimizer fine-tuned. 7.62 Impedance limit during optimization raised from 1 to 5 ohms. ZMIN in YO.SET changes impedance limit. Good-enough peak/RMS F/R bias calculated separately for each frequency. Optimizer once again rejects design trials with 0.15-wavelength elements. Mismatch-loss and low-impedance colors shown when setting colors. Better annotation for plot overlays and comparisons. Conductivity value can be set with Enter key. Minor bug fixed in NEC. 7.63 Minor bug fixed for untapered elements with a zero-length taper section. Minor change to conductor loss calculation. 7.64 Element-current phase velocity displayed. 7.65 Cosmetic VBE bug fixed. 7.66 H-plane pattern sketch glitch when F/R region not 90°-180° fixed. Cosmetic changes for Tradeoffs menu, graphs labels, and plots. Gain figure-of-merit includes mismatch loss. Rounding bugs fixed. 7.67 Random number generator modified. 7.68 NEC plots and command-line results include mismatch loss when specified. Untapered AO output files use symbols. 7.69 Random number generator uses assembly language and new seed generation. Pressing X to abort the current trial does not advance the restart count. INT 15h delay replaced with timer wait. Generalized value.asm used. 7.70 PCX image can include a border. 7.71 Slightly more accurate wire gauge expression. Denormal flag not included when testing for floating-point exceptions. Re(Z) changed to Zr. 7.72 YO-Pro becomes YO, callsign display and linear-field plot removed. Forward gain not renamed when mismatch loss is enabled. NEC uses current directory instead of TEMP for files. Bug fixed in Conductor Material menu. Zr optimization and Alt-Z function removed. Numerical entry right-aligned with no cursor to match AO. Cursor blink rate added to YO.SET. Cursor changes. Font changes. 7.73 Screen flicker eliminated when changing Yagi with mouse when no VBE. Polar and rectangular plots updated to match those of AO. ^C changes colors instead of F5 to match AO. Graph resolution defaults to one pixel. Initial mouse sensitivity halved. N key normalizes plot overlays as well as plot comparisons. 7.74 VBE, PrtSc, Watch Trials, and Abort Trial functions removed. Notes highlight, YO.INI validity check, and phase velocity curve removed. Plot displays both overlay titles when different and never filenames. YO plots only total-field AO plot files. Phase data in plot files is optional. Single-sided F/R notation changed to double-sided (90°-270°). NEC approximation distance defaults to 1 wavelength. Bug fix: initial graph for spot-frequency designs saved. Position deviation based on adjacent-element spacing. YO writes all frequencies to AO output files. Right mouse button in files screen does not inhibit next execution. Reflector position variable when boom length not fixed. Reflector position normalized to zero in AO output files. Minimum-bracketing bug for Yagis with two or three elements fixed. Series reactance replaces series reactor in ideal match. YO looks for YO.SET and YO.INI in the current directory. 7.75 PCX border, file naming, and file overwriting like AO. Yagis per second continuously displayed in upper-left screen corner. YO can eliminate screen flicker during optimization. Bug fixed in mouse event handler. Mouse range restricted on main screen. YO turns off mouse cursor for PCX image. Upper case once again works in Notes. Graph resolution always one pixel. 8.00 Differential Evolution optimizer. YO can individually calibrate any model to NEC. SSE 4.1 vector instructions increase speed by a factor of 3.3. Gain, F/R, and SWR response flattening replace frequency weighting. Optional 2° pattern resolution improves F/R accuracy for long Yagis. Individual element dipole factors improve E-plane pattern accuracy. YO can optimize matching network rod length and capacitance. Mouse can alter fixed dimensions and dimensions during optimization. YO can list files in a YO.SET directory without the complete path. Shift key shows results for the second and fourth of five frequencies. Minimum phasing line and Yagi impedances can be individually specified. Reflector position once again fixed when boom length allowed to vary. NEC.PF gain corrected when mismatch loss enabled with ideal match. NEC matrix factor speed increased by a factor of 4.75. NEC uses perfect ground by default to match YO. YO displays NEC element-current profile. Automatic graph scaling improved. F/R can use average rear power. Tradeoffs triangle can be disabled. Dual driven element model improved. Gamma match and T-match models improved. Mounting bracket model revised and corrected. Balun lead spacing independent of feedpoint spacing. Ideal match revised and SWR graphed without refinement. Scientific notation suppressed for E-01 to E-05 in output files. Output files have full numerical precision. All AO output files use symbols. Inverse tapering accuracy improved. Undo/redo better handles fixed dimensions. Graphics symmetry artifact corrected. GIF output graphics replaces PCX. Yagi file format simplified. Dimension rounding refined. 72 elements maximum. 8.01 AO output includes shunt reactances for direct feed and hairpin match. First taper section of tapered AO output includes any boom correction. YO & NEC compensate tapered element length for end cap diameter.