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--- projects:hadie [2011/01/19 10:27] – [Antenna] fsphil
+++ projects:hadie [2011/07/10 18:54] (current) – fsphil
@@ Line 58: / Line 58: @@
 The flight code for Hadie-2 is available here: http://github.com/fsphil/hadie
 ===== Third Flight =====
-A third flight is planned for mid-March 2011. The plan this time is:
+The third flight launched a few months later than planned, on the 4th of June 2011. It recorded a maximum altitude of 31616m at 12:57 BST. This was a repeat of the previous flight with a few improvements:
-  * A proper PCB instead of strip-board.
+  * A much better 1/4 wave vertical antenna, made with just coax and no solder joints.
   * Add a 16-bit checksum to the SSDV packet structure.
-  * Use Reed-Solomon error correction on the telemetry strings.
+  * Fixed a trivial bug that caused the baud rate to be slower than expected.
-  * Have dl-fldigi configured to use a narrower filter width.
-Apart from the antenna problems everything went extremely well for Hadie's first solo flight, so this flight will not change too much.
 ==== Antenna ====
-I plan to use a 1/4 wave vertical again, but made in the style of the bazooka vertical used on the first flight. The end of the coax will be stripped back 1/4 wavelength, with the outer shield folded back and split into the four radials. To help keep the antenna from flexing as the payload spins, the ends of the radials will be fixed to the payload box and a straw placed over the vertical element. Without any solder joints it should be much more reliable than my previous attempt at this style of antenna.
+After the massive failure of the antenna in hadie:2 I decided to make this one without any solder joints at all. Only RG58 coax was used, with the outer insulator stripped back just over 1/4 wavelength long and the shield carefully untwisted and split into the four radials. I left the inner conductor and insulator as is, just placing a straw over them to keep it from flexing during flight. The radials where taped to the bottom of the box with gaffer tape, and an SMA socket crimped onto the other end of the coax.
+The improvement over the last flight was dramatic, with reception of telemetry and image data from over 500km away! The small mag-mount on the car was more than enough to receive telemetry during the chase, only weakening when we drove underneath the payload to get ahead of it. We didn't need to use the yagi at all this time.
+==== Landing ====
+We managed to receive telemetry all the way to the ground and after landing. It stopped descending at a surprisingly high 361 metres, which turned out to be because it landed 12 metres up a tree in a small forest on a mountain. The first two attempts to recover it failed, finally managing to cut it down on the third go. We used a 10m pole with a hook knife on the end to cut each of the four cords holding the payload up.
+==== Images ====
+All images including the live SSDV images can be seen here: http://www.flickr.com/photos/fsphil/sets/72157626013096240/