USB cable hacking went a long way. Having the USB cable tied in a knot directly over the antenna jammed it. The cable was shielded but probably leaked high frequency energy from Vbus.
Next came moving the antenna outside the remote control. It seems to do better outside the case.
Antenna inside case sucked.
Antenna routed outside case.
Transmitter soldering job.
Next, converted all the receiver antennas to loops. The TRC101 datasheet prefers loops above all others. They're robust enough for 1 radio to transmit on top of a receiver.
The biggest gain came from separating the RF components from the Earth.
Hanging the transmitter in a tree was optimum. Putting it on a tripod was 2nd. The tree hanging was what did it for the 1st boards & it gives the same results with new boards.
The receiving end testing different ground stations.
In summary, we now have
AFC of +15/-15 Fres
receive bandwitdh 400kHz
transmit bandwidth 165khz. It won't work any higher.
86206 baud
loop antennas for everything, isolated from USB cables
The Marcy 1's just don't have as much power as 72Mhz & XBees. 72Mhz with good antennas used to go 600ft easily. If buying replacement 72Mhz antennas, GWS Pico receivers, & crystals isn't your thing, consider tethering manual override to the ground station.
FLIGHT TESTS CONTINUE
Hand launches don't work. Marcy 1 is too unstable. Threw her in the air & she spun vertically until smashing into the ground. Don't tell Major Marcy about this.
A few autopilot flights with automatic takeoff showed Marcy 1 can take off & stay inside a cloud over the sonar but needs attitude sensing to get the precision hovering of a human pilot. A human making constant cyclic inputs can keep her very precisely in position. She's not statically stable enough to hover without feedback.
Faster RPM would make her more stable but that defeats the purpose of the Marcy 1 development program. She's supposed to extend flight time by using slow RPM & throttle pulsing won't work if the RPM is too high.
A magnetometer on the equator can sense pitch easily but not roll. In Calif*, it can sense pitch & roll but only pitch shows up on monocopters. Roll may change the azimuth result.
That leaves 1 thermopile taking 4 readings per revolution, eliminating indoor use. Marcy 1 can be used as a testbed with thermopiles but would have to be rebuilt using a 4' wing, GPS, & barometer for outdoor use.
VIKA 1 RIDES AGAIN
Finally had some Vika 1 flights with the Marcy 1 radios for manual override. Made a mosaic from the 86kbit UARTCAM. The Marcy 1 radios are only reliable enough really close to the ground station, so you're basically tethered.
The only heroines near Silicon Valley are the ones brought in with marriages, so Valentine's day for men is a flying day. We went above the Major Marcy dishes. They moved, probably to support Haiti operations. Drones in the middle east use uplinks in Germany. Drones in Haiti would use uplinks in Mexico or maybe even these particular dishes.
Surprisingly tight position for a 3 DOF IMU. Position gets sloppy if there's a lot of horizontal motion. 7 months & we've never seen Her in real life & probably never will.
Comments
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