I want to revisit this post after flying my unit a handful more times: I flew it 3 times a couple weekends ago at ROC. -Flight 1: couldn't get unit to power on until the motor lit and I started getting telemetry. Post flight tear down showed one of the switch wires not being connected super great. My bad on that one. -Flight 2: perfect flight with full tracking and dual deploy. -Flight 3: no configuration changes-just snipped charge wires and twisted new charges on without opening up the altimeter bay. Altimeter gave proper power on beeps (4.1V, pad mode) but failed to transmit anything at any point, perform any duties during flight or log any data. I cycled the power a handful of times to no avail. This is similar behavior to the issue I was having at Balls with nearby transmitters, minus the nearby transmitters.
These flights were flown on the same sled I used at Balls with a Stratologger on the backside in a fiberglass bay. There were no other RF transmitters in the rocket on these flights. Transmitting APRS every 10 seconds, and the frequency was clear aside from the flight where the telemetry worked and I was picking up packets from the unit. Is anyone else having any similar issues with the TeleMega? -Andrew On Thu, Oct 9, 2014 at 2:07 PM, Andrew Wimmer <[email protected]> wrote: > I flew my TeleMega, serial #1639 with 1.4.1 at Balls in a 2 stager. > Ran into a few problems, as follows: > > 1. Unable to connect in to TeleDongle in idle mode. I had previously > found that I couldn't get a connection with the TeleMega in channels > 7-9, so I was using channel 3 for this flight. I was unable to get a > connection in idle mode in Channel 3. I haven't explored other channel > or tried to re-create this problem. > > 2. RFI issue with Beelines. The rocket had 4 Beeline trackers in it as > follows: > - 1x 100mw 70cm GPS aprox 30" above the TeleMega on 434.350 > - 1x 70cm beacon aprox 6" below the TeleMega on 438.850 > - 1x 16mw 70cm GPS aprox 48" below the TeleMega on 434.350 > - 1x 70cm beacon aprox 48" below the TeleMega on 438.350. > With any combination of the beacons turned on, attempting to startup > the TeleMega in pad mode would result in battery voltage beeps, pad > mode beeps followed by silence, on both the radio (I was listening in > to 434.850 on my FT1DR) and buzzer (ie, no continuity beeps). After > spending an afternoon troubleshooting this, it was determined that > turning on any combination of the Beelines prior to startup would > cause this, but turning them on after the TeleMega was transmitting > didn't result in any adverse affects. > In investigating the manual post-flight, I did note the point about > twisting wires, which I did not do on this flight as I hadn't seen it > previously. I'm not certain that that would have fixed the issue or > not. It would be really really great if there was a separate manual > for each product. It's very easy to miss things when you are > intentionally skipping a significant portion of the manual since it > doesn't relate to the product you are interested in. Additionally, > this is the only time I've seen a suggestion in a manual to twist > wires. This comes in a section of the manual, that in most other > rocket electronics manuals, is reserved for things like "how to attach > wires to screw terminals" and "how to not have battery issues", which > experienced fliers have a tendency to already know and skim. > > 3. Accel calibration with temp. After spending an afternoon at the pad > troubleshooting the above issue, the rocket sat overnight and was > powered up within 30 minutes of sunrise. I was unable to get the > TeleMega into pad mode until it had been in the sun for 10 minutes, at > which point, it went into pad mode and read a Z accel of -5.1m/s/s. We > left the rocket in the sun for the next 45 minutes and in that time, > the Z accel when it was being held vertically had migrated from -5.1 > to -3.3 to -2.2 and was continuing its upward trend. The accelerometer > was previously calibrated at room temp 2 weeks prior to the launch. > > 4. Angle lockout for staging-not so much a bug as it's probably > exactly what it's designed to do, but I had the telemega setup to do > staging and also staging inhibit on a backup timer. The TeleMega was > to stage if conditions were after burnout, >4 seconds into flight, <25 > degrees and >400m/s. I had an additional circuit acting to open the > igniter circuit on a timer I was using for backup. This was to occur > if the angle exceeded 25 degrees at any point. Shortly after the > breakup, the inhibit circuit fired as anticipated. What I didn't > expect was for the fire circuit to fire as the rocket rolled back > within 25 degrees of vertical 2 seconds later. Fortunately the igniter > had already ripped out of the motor, so no harm was done, but this > could have been interesting had it not. > > Anyway, hopefully this helps alleviate frustration for at least > someone. I understand the issues now and they're more annoyances that > I can live with than anything. As I hadn't seen them documented > previously, I figured I'd put them out there. Let me know if anyone > has further questions or needs more elaboration. > > Thanks, > -Andrew >
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