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Posts posted by Flutter

  1. Hi,

    I got the TX40 a couple of months ago. I have been flying it with my modified X-UFO 10-20 minutes in total. Today I was going to power it up again after having finished a new pan-tilt setup but it seems to be totally dead. I have measured the current draw and it is only 0,14mA (should be 220mA).

    Anyone experienced this?

    I do not want to remove the wrapping to measure the voltage regulator yet before I have checked with Kilrah regarding warranty. I was really happy with this cam. Great quality as long as it worked ;) Fits perfect to the small X-UFO as well....

  2. I bought a JVC GR-D290E today which I will use for video capturing since my Panasonic NVG400 doesn't match with the KX131 and KX141. I got the cam for less than half price since it is a demo model. When I got home I discovered that there is no AV-cable included. The AV connector on the cam is flat almost like a USB connector. Anyone knows the name of this cable or where I can get a new one?

  3. I am currently setting up a KX-141 cam, BWAV 500mW TX and RX. I use a Panasonic NV-GS400 for recording and my challenge is to get rid of the red/green lines that appear on the cam-monitor. These do not show up when using the television. Also, using the same RX but a smaller 10mW cam/tx the picture is nice on the Panasonic.

    I have read about these issues when matching KX-131 with the NV-GS400 and but not about any solutions yet.

    Anyone have any suggestions how to overcome the red/green lines? I would rather swap the KX-141 than the NV-GS400 (due to cost... :) )

  4. I am currently using about 15" of separation but this doesn't help a lot. The rc rx is not shielded at the moment (emi penetrates shielding???)

    The "antenna down" range with the 15" separation is about 90-100ft....but it should really be 150ft +. The radio tx is a JR 9303 and the rx is a JR R770S.

    The rc antenna is routed along leading edge of wing and the 900MHz antenna is positioned vertically in aft of the fuselage.

    Does anyone know the relationship between antenna down range and extended antenna range?

    I don't have a photo of the setup at the moment.


  5. I have a problem with a 900MHz tx/rx operating on 1watt very close to a JR 72MHz rx (PCM). The range of the JR rx is degraded significantly due to EMI from the 900MHz system (30ft with antenna down on ground test). Since both radios have to go into a 60 size trainer the separation between components is limited. Is there an effective way of "shielding" the 72MHz rx from the 900MHz system? Should I wrap the 900MHz device in copper entirely ;) ?


  6. Diyguy. Imagine that you are in a car driving on the highway. You put your hand (flat) out the window, so the palm is paralell to the road. Now the AoA is zero of the hand relative to the airflow, and the road, no lifting force felt, only the force paralell to the road, pushing your hand backwards. The flight path angle is also zero, the car moving paralell to the road (earth fixed system). Now, tilt your hand a little , exposing the palm to the wind, you will feel the lifting force. The hand has still the same "flight path" angle, following the car down the road, but the AoA has changed, positive, resulting in a lifting hand (or wing). Tilting the hand down again, past neutral, will push your hand downwards, due to negative AoA, but the flight path is still unaltered. Go for a ride :=)

  7. The stall warning device on the link works after the same principles. More advanced you can make a little fin on a potmeter, place it somewhere where the airflow is relatively undisturbed and measure the angle of attack. Very commonly used. Some fighters use probes with two sets of pressure holes. When the aoa changes there will be a pressure difference measured, the probe adjusts so the pressure equals, and the amount of adjustment needed gives the AoA. Not very practicall for my Cub I guess..... :).....but a "bitching betty" would be cool..... Warning warning.....pull up.....

  8. I am not sure if I quite understand you now. Angle of attack should not be mixed with flight path angle, the latter one being the angle indicated on a horizont indicator. The AoA is the relative angle between the wing and the free flow. If you have a negative angle of attack on landing you most sure have negative lift (or close to zero for a non-symmetric profile), but negative flight path angle is common until flaring out for touch down.

    If I will make myself an AoA indicator I will make a small flap that will be bent down, actuating a microswitch, at leading edge. When approachin stall AoA the flap should be "grasped" by the flow and flip over, releasing the switch, the stall alarm should sound. The angle of the flap would probably have to be greater than your expected stall angle, but I will not go into the that theory..... Anyway, I would start with a flap angle of, say 15 deg, then do a flight test, adjust, test....and so on. Mechanically very easy, and should be a good indicator.

  9. Just want to point out that stall is only dependent on AoA, not velocity. Of course, as lift depends on AoA and velocity, a low velocity will require greater AoA to maintain proper lift. The little "flap" on a full size plane actuates when the AoA gets too great (maybe 14-15deg), not when speed is too low.

    Aslo, since the mass of the plane will differ some from flight to flight (and during flying due to fuel burn) the "stall speed" will differ. "Stall AoA" will not change, since it depends on the wing itself.

  10. This is one of the sub routines. If I reset the pic I can push my 3rd test button, and the servo moves....but to the same pos. no matter what value I choose for the duty cycle CCPR1L.

    void servo3(void){

    TRISC = 0b.1000.0000; /* Config. PortC.2 for out put=0 */

    CCP1CON =0b.00111111; /*Conf. CCP1 module for PWM operation */

    T2CON =0b.00000100; /* Timer2 Prescale 1 (to obtain 19.53kHz) */

    PR2 = 255; /*PWM period (0xFFh) */

    CCPR1L = 100; /*about 40% duty cycle*/

    led3=1; /*For identifyig the respective interrupt*/

    del(); /*delay routine*/


  11. I hae been trying to control a standard servo for some time now, but I can't get my routines to work properly.

    Can anyone give me a clue about the right config on





    just so I can get it to work. I only get a movement on the first interrupt, then

    changing the value of CCPR1L gives me only a small tick, changing the position maybe 1deg. I most likely have configured the above registers wrong.....

    I have read the theory, but obviously don't understand it in total...so some working values would be great!


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