Recap of EOSS-70/71

Recap of EOSS-70/71

Each flight has a page dedicated to it to cover individual idiosyncrasies. Common information for both flights found here.

LAUNCH DATE: August 2, 2003
LAUNCH TIME: See individual Flight Recaps
LAUNCH SITE: Deer Trail (directions)

EOSS Frequencies:

  • Preflight Net:
    • 147.225 MHz 8 pm MDT preceding Friday night
      • 145.160 MHz simulcast in the Springs
    • 146.640 MHz will serve as a backup frequency
  • Tracking and Recovery Operations
    • 448.450 MHz 100 Hz tone (primary EOSS T&R Repeater) Pikes Peak FM Association
    • 146.550 MHz simplex (same simplex for field and launch ops)
  • HF Net during Flight
    • 7228 KHz (see notes about this freq)
    •  starting at 12:15 UTC (6:15am MST)

CU Frequencies:

  • The Vans will be using Family Radio Service (FRS) channel 8 - 467.5265 MHz
  • Backup FRS channel 1 - 462.5625

Internet Gateway Stations:

For K�ANI-11

  • K�YG-7 - Mark Patton

For K�YUK-11

  • K�QED - Lee Inman
  • K�YG-7 - Mark Patton
  • K�UT-3 - Bill Beach

For W5VSI-11

  • K�QED - Lee Inman
  • K�YG-7 - Mark Patton
  • K�UT - Bill Beach

BACKUP iGaters

  • KC�CAT -  Gerry Singer
  • KI�KN - James Cizek
  • KC�LNO - Mike Skinner
  • K�ANI - Larry Cerney

EOSS wishes to express our sincere appreciation to those stations above who iGated the balloon APRS telemetry onto the internet.

We are relying heavily on real time position information available on the net to allow the FAA controllers to have up to the minute location data to assist them in traffic control.

The backup stations for each balloon provide excellent coverage. If you go to and enter in the callsigns of any of EOSS's APRS payload systems to retrieve the raw position data you will note that all of these stations contribute to the flow of information. And in the event of a station dropping out momentarily, the others pick up the slack quite nicely.

Thanks again guys! The FAA (and EOSS) are very grateful for your assistance in this endeavor.

EOSS Grid:

Location Grid X Grid Y
Punkin Center 25 10
Kit Carson 74.5 4.5
Deer Trail 6.5 62.5
Stratton 84 41.5
Predicted Landing 39 25.6

Suggested N�LP Grid Calculator Reference Point:

Since Punkin Center is located on a predefined (scoped by trackers with GPS) latitude Longitude you might consider using that as your reference point.

The lat/long is:

  • 38.852083 decimal degrees north
  • 103.70053 decimal degrees west

And that would be associated with Marty's X/Y coordinates of 25,10 as shown above


  • Ground Station Photos by Nick Hanks
  • Landing Site Photos by Jim Zimmerman
  • Landing Site Photos by Marty Griffin
  • Car Crash Photos by Jim Zimmerman, K. Mark Caveziel and Marty Griffin


Playing these clips in sequence will essentially recreate the flight. Very minor edits have been made to clean up the beginning and ending of each clip.

Each title refers to the nature of the clip, however it does not preclude other activities. For instance, If you download the "Burst of EOSS-70" you will still hear traffic referring to the ascent phase of EOSS-71".

Although I'm not heard extensively on the tape you may notice that people appear to be talking to me and then there is silence followed by more traffic directed to me. But I appear not to be responding. Well actually I was desensing the receiver during transmissions while the pre-amp was inline. When that was removed, I seem to reappear with a very weak signal. The weakness is an artifact of desense as I've never had complaints on my actual signal into Pikes Peak.

The recorder used was a Sony ICD-MS515 pocket digital voice recorder. It was set in VOX mode. If someone drops the repeater and 30 minutes pass before the next transmission there will only be a second or two of silence between one transmission and the next. Keep this in mind when listening to activities.

Actual elapsed time of the event was approximately 7 hours. As you can see, VOX reduced that to 3.8 hours of actual radio traffic.

The Sony was plugged directly into the record out jack of an Icom IC-R8500 receiver. The antenna used was a discone. That's why the noise. With a normal receiver and antenna the PPFMA repeater is full quieting at my location. May have to change the receive setup if I keep doing these audio recordings.

Mark Conner put me to shame by running one of these files through Sound Forge and filtering out the noise. So, I spent some additional time attempting to learn how to do that with Cool Edit Pro (my audio editor) and as of 8-Aug-03 these files have been considerably cleaned up. There is still noise but I was as aggressive as I could be in removing it without impacting the voice quality to any great extent. Thanks for pushing me in the right direction Mark.


Tracking and Recovery Recap
by Benjie Campbell, W0CBH

Great time on this recovery. We didn't spend too much time eating in Limon, ha! We were on site early and had time to try and get the &^*%$#@)(*&^ computer working right. Got it partially working, enough to see where I was and go from there. I had both the D700 and D7 working, so we could at least see where the payloads were.

I had time to explain the procedure to Carla, so she took all the bearings and gave the reports to Marty. She was pretty proud of herself having done that. I finally have found someone who can see the dial on the compass correctly, ha!

The convoy that was following the payloads was impressive. We counted over thirty cars going by our tracking site. Lots of dust.

Several ranchers came by and asked what we were doing. Had good talks with both of them. They were pretty interested, so I want to get some brochures or cards printed up with the web site, so in the future I can just hand them a card and say "go check it out". One of them said it gets pretty boring out there, and they need some diversions to keep them sane, ha!

We need the Public Information officer for the group to find a newspaper out there that might run a story on us, with some pictures and see if we can start a group of rancher/trackers out there. Maybe an open house in Deer Trail on the next flight? I know we have enough to do, but these people seem to be pretty interested. Also, the school teacher that helped us locate some land owners seemed pretty interested. Maybe we should make a trip to her school for a show and tell?

This time the equipment worked well, antennas and radios. The computer is still a problem, and I need to mount it on a table like Chris's. We had a good time teasing him about Carla's bearings.

The weather was good. We had enough trackers to leave some stationary and send others to retrieve the payload on 70. That was a change from several flights. Good to see everyone also. Really enjoyed talking to some of the students and supporters.

I haven't heard about the accident yet, hope the person is okay????

I am planning on getting an FRS radio, so I can monitor and talk to some of the people that we fly for. It might also be an idea to take along a "CB", sorry I said that, but it is another communications tool we might be able to use. It might be a neat test to see how many of us can communicate on that band, and see if it might work for non-hams to participate with us in taking bearings?????


HF Radio

Bruce, NA�BR was our HF net control.

We try and start an HF net approximately 45 minutes prior to launch on 7.228 MHz. If that frequency is busy we try 7.235 or 7.240 MHz.

Conditions were very unfavorable for a 40 meter net today and so it was suspended early (14:00 UTC) because of lack of participation.