Amateur Radio on Balloons - Ilmari 2003 IRC-5
 

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SUPER ILMARI REALITY CHECK meeting number 5

2003-01-18 klo 13:00

TTY (a.k.a. tut.fi), TAMPERE

(Most meetings have been at Helsinki, but some participants are from Tampere region, thus we decided to have once session closer to them...)

Meeting notes:

  • Translator:
    • New subassembly: controlled power switches and current measurement subsystem differential amplifiers at their own card:
      , [2].
    • CW-beacon with FSK ? Idle/Mark separation about 600-700 Hz. This at both 2m, and 80m beacons.
  • Balloons: We got a donation of 5 Totex TX1200 balloons.
  • Separation mechanics:
    • OH1MRH has done experiments with 0.5mm Nylon fishing-line melt-cutter. A wee bit of warmth -> nipsnaps
    • Problem has been finding thin resistive wire, a 0.5mm Kantal-wire is "a bit" too thick needing lots of current to heat up sufficiently.
  • IHU
    • Estimated power consumption: With various power-save tricks it should be possible to operate below 200 mW of total power, with 70% (inefficient) PSU this drains under 15 mA from the 14V battery.
    • Lattest card revision has 33 A/D inputs, as those are being consumed at alarming rate..
    • All major components have been acquired either as samples, or bought. Something small is still missing.
    • Software writing has begun, more info at the IHU page.


Latter things:

System total mass estimations have begun.

An alternate radar reflector made of aluminized paper: 9g.
One strip of paper, and one strip of sticky-tape. Edge length 18cm. An example of Japanise artform of Origami ;)

This used a strip with dimension ratio of 1:4. Also a square recipe exists, but while doubling edge length, will also quadruple mass to above 40g.




Larger version without double-ply paper. Using glue, and sticky tape. Edge length 35cm. 25 grams.

Matti Aarnio <matti.aarnio@zmailer.org>; OH2MQK

 

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