W5HN North Texas Microwave Society NTMS 1 Craig S. Young, KA5BOU 10 GHz Flyswatter Antenna Experiment

W5HN North Texas Microwave Society NTMS 2 The Problem No Room at the Inn! –And still missing 2304/3456 loop yagis Feedline Loss at 10 GHz I Don’t Climb –Want access to transverter

W5HN North Texas Microwave Society NTMS 3 Potential Solutions Roving –Great when the weather cooperates –Enhancements don’t always coincide with roving times “Flyswatter” arrangement –Well documented by W1GHZ MUD Paper Website Recent QST Article

W5HN North Texas Microwave Society NTMS 4 Flyswatter?

W5HN North Texas Microwave Society NTMS 5 Actually, a Periscope An antenna configuration in which the transmitting antenna is oriented to produce a vertical radiation pattern, and a flat or off-axis parabolic reflector, mounted above the transmitting antenna, is used to direct the beam in a horizontal path toward the receiving antenna. Note: A periscope antenna facilitates increased terrain clearance without long transmission lines, while permitting the active equipment to be located at or near ground level for ease of maintenance.

W5HN North Texas Microwave Society NTMS 6 Performance Analysis Estimated performance at 10 GHz –Courtesy W1GHZ Excel Spreadsheet

W5HN North Texas Microwave Society NTMS 7 Designed to mount to Rohn 55 Tower (17” leg center-to-center) Includes rung hooks for easier installation Clamps to tower legs System Design – Top Reflector 32” 1 ¼” Angle Iron ¾” Angle Iron

W5HN North Texas Microwave Society NTMS 8 Fly Swatter on the Ground

W5HN North Texas Microwave Society NTMS 9 System Design- Dish Mount 32”

W5HN North Texas Microwave Society NTMS 10 Dish Mount on the Ground

W5HN North Texas Microwave Society NTMS 11 Elevation Control Used a TVRO actuator for control with a Winegard DM for feedback. –Actuator uses 12VDC – polarity changes direction Integrated Az rotor controller and Elev control into single chassis with room to add future polarization controller

W5HN North Texas Microwave Society NTMS 12 Flyswatter Controller

W5HN North Texas Microwave Society NTMS 13 Complete System

W5HN North Texas Microwave Society NTMS 14 “First Light” NT5NT Beacon

W5HN North Texas Microwave Society NTMS 15 Recent Activity – Aug UHF Contest Of course, there were only 2 10GHz entries from NTX –KA5BOU –NM5M Both with same 10 GHz score! –Congrats, Eric!

W5HN North Texas Microwave Society NTMS 16 Recent Activity – Jan VHF Contest Worked W5LUA and WW2R Direct –Once we found each other in frequency! –3 and 6.4 miles, respectively Worked NM5M and WA5VJB via rainscatter –16.5 and 40 miles, respectively, via direct path –However, was working off storm near Red River Approx 100 mile path to Eric Approx 120 mile path to Kent

W5HN North Texas Microwave Society NTMS 17 Issues In traditional dish installation for terrestrial work, elevation and polarization are fixed More Degrees of Freedom! –Azimuth –Elevation –Polarization –Frequency Azimuth Elevation Polarization

W5HN North Texas Microwave Society NTMS 18 Issues Alignment – Base to Reflector Pointing Resolution Elevation Polarization

W5HN North Texas Microwave Society NTMS 19 Alignment (base to reflector) “1001 uses for a laser pointer” –#907 – use it to find the center of the dish mount relative to the center of the flyswatter –Mark cross-hairs on base

W5HN North Texas Microwave Society NTMS 20 Azimuth Pointing Resolution of current rotor controller is 6 degrees However, every time I “tap” the meter face, the needle moves +/ degrees! Currently, I “get it close” with the meter and then fine-tune visually against the yagi-array

W5HN North Texas Microwave Society NTMS 21 Azimuth Pointing

W5HN North Texas Microwave Society NTMS 22 Elevation Issues Winegard unit appears to be not 1:1 –I set it such that 45 degrees on readout is 45 degrees actual elevation using protractor/level – resulting in zero degree elevation of beam (at the horizon) –However, flat down (storage position for least wind load) is 9 degrees on the readout –Highest elevation reads 63 degrees, but is actually closer to 70 (didn’t measure) –May be where I have sensor mounted relative to flyswatter pivot point

W5HN North Texas Microwave Society NTMS 23 Elevation Issues (cont’d) One degree of flyswatter tilt = 2 degrees of beam tilt! 45º 0º 70º 50º Beam=2(Elev) - 90

W5HN North Texas Microwave Society NTMS 24 Elevation Issues (cont’d) Higher flyswatter tilt = loss from spillover

W5HN North Texas Microwave Society NTMS 25 Polarization Either dish or feed must rotate with flyswatter to maintain correct polarization

W5HN North Texas Microwave Society NTMS 26 Polarization 180 degrees of swing required on dish-end to maintain correct polarization –Must be synchronized to flyswatter Current polarization control via “armstrong” method Angles in this half have equivalent polarizations in opposing half

W5HN North Texas Microwave Society NTMS 27 Next Steps Sun Noise Measurement? Experiment with Other Bands Permanent Dish Mount with Radome Finer Resolution Az Control Another 10ft?

W5HN North Texas Microwave Society NTMS 28 Sun Noise? What is lowest elevation for good sun noise measurement? Given current geometry and assuming max flyswatter can be rotated in elevation is 65º, highest beam can be steered is 40º –Is this high enough?

W5HN North Texas Microwave Society NTMS Analysis 50’ run of LMR-600 would have approx 3.6dB loss

W5HN North Texas Microwave Society NTMS Analysis My current plan for this band is a 12’ Directive Systems loop yagi (25.2 dB) at tower top (61’). Assuming 70 ft. of LMR-600 (~5dB/100’), total system gain would be 21.7 dB

W5HN North Texas Microwave Society NTMS GHz Analysis With 2 ft dishWith 1 ft dish

W5HN North Texas Microwave Society NTMS 32 Dish with Radome

W5HN North Texas Microwave Society NTMS 33 Finer Az Resolution (and polarization sync) AA5C had great article in recent QST on fine azimuth control for 24 GHz My plan is to take a similar approach for both flyswatter azimuth control and polarization control –Controlled via BASIC Stamp Microcontroller –Will allow synchronization of polarization with flyswatter azimuth –Will calculate and display actual elevation as well

W5HN North Texas Microwave Society NTMS more feet? The KA5BOU “Bowl”

W5HN North Texas Microwave Society NTMS 35 Questions?