TEXAS HAM RADIO BALLOON PROJECT 16
AUGUST 9, 2008 HILLSBORO
The North Texas
Balloon Project was launched on Saturday, August 9, 2008 from the
Hillsboro Airport South of Dallas, Texas
The planned high altitude balloon
carried Amateur Radio Transmitters aboard including a cross band
2/440 repeater and voice beacon along with GPS locating
(Details of the radio equipment aboard can be found at
this link ( http://www.ntexbp.org/ )
This page contains audio
files from the voice beacon and the 2 meter side of
the onboard repeater transmitters.
The recording QTH was located in Gun
Barrel City, Texas, about 60 miles from the launch site at the
Equipment , Software and web
Compaq Computer using Wave Pad audio
Receiver was a Radio Shack HTX- 212 (Used "A"
and "B" vfo with preset frequencies)
Receiving antenna - 2 meter
homebrew Slim Jim up about 10 - 12 feet from the ground fed with
RG-58 coax. Total length of coax, about 20 feet.
FT-107 monitoring HF 40 meter ground frequency with Hustler
http://www.dfwaprs.net/ (For GPS
locating, altitude, etc)
started listening to the voice beacon and the repeater downlink at
exactly 8:30AM Central until I first started hearing ANY signal
from either of the balloon transmitter frequencies by switching
between the A and B vfo's on the receiver. At 21 minutes from the
presumed launch time, I started hearing very weak signals and
started a continuous recording of the flight at about the 22 minute
I did not hear a countdown to launch on 40 meters
due to extreme QRM so it is presumed that the launch took place
at the scheduled launch time of 8:30AM Central time.
At 21 minutes past the 8:30AM time
(8:51AM local), I started to hear some very weak signals and started
recording shortly thereafter, and over the next 2 hours and 19
minutes, I recorded the entire length of the flight from launch
until presumed landing.
The below recordings are only a small
portion of the audio recorded starting with the earliest at 21 to
22 minutes into the flight: Some are large files so be
ntbp22min.mp3 (First audio heard from
ntbp26min.mp3 (Repeater audio)
ntbp29mins9audio.mp3 (Repeater audio)
ntbp37minbeaconid.mp3 (Beacon ID in
beacon status report from 30,000 feet) 369kb
(Voice beacon status report at 1422 UTC) 422kb
Final Voice Beacon
It is believed
that this was the last transmission heard by anyone due to a
malfunction of the beacon transmitter. This appears to have happened
on the way down at around 49,000 feet (assuming data was
accurate), with an "inside" temperature of -46 degrees! (Minus
There were no further
transmissions from the beacon transmitter heard by my
station. Listen closely to the recording, it ends abruptly
and goes to noise when it attempts to start another
ntbplastbcnrpt1542utc.mp3 516kb (Final Voice beacon heard! Status
report at 1542UTC)
observations and notes:
repeater continued to function normally thru the remainder of the
flight and the last transmission heard at this station, although
very weak, was at about 13,000 feet according to GPS tracking. It
was in the noise level and no more transmissions were heard below
As you listened to the recordings, you can
tell that many were "full quieting" (no background noise).
recordings made were Full Scale on the S meter on the
On the average, most signals heard
from the balloon had some heavy oscillation in the S meter readings
due to movement, etc of the balloon.
According to GPS readouts, the maximum altitude
appeared to reach about 83,000 feet as reported on the
http://www.dfwaprs.net/ web page.
Below is a map of the landing area taken
from the above web page.
On the map, W5SJZ-11 is the balloon. You
can see various "chase" vehicles also.
The landing area is about
10 miles East of Meridian, Texas near highway 22, West of Lake
Whitney, Texas. Total distance from my station was about 84 miles
with a flight distance of about 25 miles from the Hillsboro airport
according to my unvarified measurements.
(Exact location of landing site may
be slightly different)
As a further note of interest
for whatever it is worth, when I was monitoring the S meter readings
on the receiver during all of the flight, I noticed that at the
"maximum" altitude, the S meter readings were weaker than during
lower altitudes. I believe this may have been caused by the pattern
of the Slim Jim antenna being very near to the ground.
"Facts and numbers" in this article are
believed to be accurate,
but, check with the http://www.ntexbp.org/ for
I hope you have enjoyed looking and
listening to the "sounds from near space" and I would like to
congratulate the very dedicated hams and all concerned at the
North Texas Balloon Project 16 for a job well done.
was a fun experience for