= NOW 30 WPM = TEXT IS FROM JANUARY 2020 QST PAGE 58 = A WAVEGUIDE FOR 1296 MHZ WOULD BE QUITE LARGE. I CHOSE TO MAKE THE MESH WAVEGUIDE WR 229 SIZE 2R29 X 1R145 INCHES VISIT WWW. WA1MBA. ORG/ WAVEGD. HTM FOR A TABLE OF WAVEGUIDE SIZES, COVERING 3R3 TO 4R9 GHZ, BECAUSE I HAD A SURPLUS PIECE TO HOLD THE MESH IN SHAPE AND A COAX TO WAVEGUIDE TRANSITION TO EXCITE IT. THE SETUP, SHOWN IN FIGURE 3, USES THE SAME CHINESE SYNTHESIZER AS THE COAXIAL LINE FOR A SOURCE, RETUNED TO 3456 MHZ, BUT ANY SIGNAL GENERATOR, TRANSVERTER, OR EVEN A SIMPLE OSCILLATOR WILL DO. FOR SAFETY, KEEP THE POWER LEVEL LOW A FEW MILLIWATTS IS PLENTY. THE SAME SENSITIVE RF DETECTOR IS USED. I MADE A NEW LONGER, THINNER PROBE AND INSULATED IT WITH A BIT OF WIRE INSULATION TO PROBE THROUGH OPENINGS IN THE COPPER MESH. PROBING THE OPEN COAXIAL LINE AT 3456 MHZ SHOWED MINIMUM VOLTAGE AT 16R4, 20R6, AND 25 CENTIMETERS, MINIMA SPACED ABOUT 4R3 CENTIMETERS AS EXPECTED, FOR A WAVELENGTH OF ABOUT 8R6 CENTIMETERS. WITH A SHORT CIRCUIT PLATE AT THE END OF THE WAVEGUIDE, PROBING ALONG THE SLOT IN THE WAVEGUIDE SHOWED MINIMUM VOLTAGE AT 8R5 AND 15 CENTIMETERS, FOR A GUIDE WAVELENGTH OF 13 CENTIMETERS. THIS DIFFERENCE IN WAVELENGTH AT THE SAME = END OF 30 WPM TEXT = QST DE W1AW <