The Eggtimer Quasar - A WiFi-enabled GPS/Altimeter

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Hmmm....now I need to save money to get a Quasar 70cm. /sigh

So many projects, so little time (and money!).
my dual band HT fell off my speaker and broke the antenna base and the volume knob shaft. :mad: :facepalm:🤬 I may have to get one of those cheap-a$$ Baofeng radios. Mine was a Kenwood G-71 that my BIL gave me and it will cost me too much to get it repaired.
 

n3tjm

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I find those Baofeng radios are pieces of junk. Also, never had much luck with Kenwood and Kenwood Clones.
I saw a fellow ham radio operator working at our local elections. We talked a bit, I mentioned that repeater activity in this area is pretty much dead. The closest repeater is no longer functioning, and the only one I can hit with an HT from my office, I only had one contact from listening for over a month... Sad really.
 

cerving

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No accelerometer. I wanted to put one in originally, but the one that we use in the Proton (which was the only reasonably priced high-G accelerometer around) went EOL, and a replacement would be much more expensive. I didn't want to have to jack up the price a lot for a feature that is, frankly, not really essential for most flyers. BTW, we are re-doing the Proton around a different accelerometer... and unfortunately the "new" Proton is going to cost more.
 

Simon Auty

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Waiting to see the instructions go up on the web site Cris so I can assess if my soldering skills are up to it.
Found the Tx and GPS/LCD easy enough although the Quantum tested me (probably shouldn’t have done it first!)
 

cerving

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They should be posted shortly after I get the production PC boards, probably in about two weeks. It's roughly about the same as building a Proton... nearly the same number of parts.
 

Dan Griffing

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No accelerometer. I wanted to put one in originally, but the one that we use in the Proton (which was the only reasonably priced high-G accelerometer around) went EOL, and a replacement would be much more expensive. I didn't want to have to jack up the price a lot for a feature that is, frankly, not really essential for most flyers. BTW, we are re-doing the Proton around a different accelerometer... and unfortunately the "new" Proton is going to cost more.
The Eggtimer website doesn’t yet show the Quasar Assembly Instructions Document.

I wamt to know if the Quasar has an option for a cutoff switch between the B+/DP+ pads like the Proton does.

This is so I can configure the Quasar with the electronics and GPS can be powered-up and the deployment system armed, but with a pull-pin safety switch used to keep the ejection charges safe until the rocket is on the pad and vertical.

This configuration makes putting the rocket on the pad and getting it ready for launch less of a hassle. Sometimes the WiFi is difficult to connect on the pad, possibly because with some launch pads there is a lot of aluminum that attenuates the signal. Because of this, its easier to do the WiFi arming protocol at the bench, if there’s a pull-pin safety switch that keeps the ejection charges safe.
 

cerving

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Correct... we don't post the documents until we have the final production boards, since we need take assembly pictures. We don't like to do that with prototypes... the boards don't look the same.

The Quasar is a single-battery design (like the Quark), that makes powering it easier. If you need to shut off the power, just put a switch on the battery leads, like you would do with any other altimeter. The GPS in the Quasar generally acquires a fix very quickly... typically in 30 seconds or less. The large ground plane (compared to the Mini, for example) makes a big difference.

There IS a way to use a pull-pin switch just on the deployments... maybe I'll put that in the docs.
 

Dan Griffing

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Correct... we don't post the documents until we have the final production boards, since we need take assembly pictures. We don't like to do that with prototypes... the boards don't look the same.

The Quasar is a single-battery design (like the Quark), that makes powering it easier. If you need to shut off the power, just put a switch on the battery leads, like you would do with any other altimeter. The GPS in the Quasar generally acquires a fix very quickly... typically in 30 seconds or less. The large ground plane (compared to the Mini, for example) makes a big difference.

There IS a way to use a pull-pin switch just on the deployments... maybe I'll put that in the docs.
Thanks. That’s what I’ll be needing to do.
 

cerving

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For a given amount of power (100 mW in our case) you should theoretically get about twice the range in open air with 70cm vs. 900 MHz. Most people won't notice, though... I've personally tracked 900 MHz units to over six miles. Not many sites have a 30,000' FAA waiver.
 

Crayok

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What if any, is the advantage of the 70cm ham band to the 900 MHz band? Just curious...
outside of what is mentioned above, it is easier to place 900 Mhz antennas within the airframe that has less impact to the radiation pattern of the antenna. Generally speaking you try not to have much of anything within a wavelength of the antenna that can alter the impedance which in turn changes the resonance of the antenna and thus the efficiency of putting RF out. This is the biggest obstacle to get the best range. In reality it is almost impossible inside a rocket (outside is best but...). If you have the means, tuning the antenna in the place where it will transmit from is best (if the antenna can be tuned). yes wandered waaay off topic

I have done a bunch of university team inspections and they do not seem to know about the "magic" of RF. Buried antennas in the ebay, right next to the support rods, right next to the GPS antenna, need a whole class on that.

I have found that once on the ground, along with what Cris said in the air, is you have about 2-3 times the distance to get something (favoring 70cm). Receiver sensitivity and antenna are big factors here.

David
 

Dan Griffing

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outside of what is mentioned above, it is easier to place 900 Mhz antennas within the airframe that has less impact to the radiation pattern of the antenna. Generally speaking you try not to have much of anything within a wavelength of the antenna that can alter the impedance which in turn changes the resonance of the antenna and thus the efficiency of putting RF out. This is the biggest obstacle to get the best range. In reality it is almost impossible inside a rocket (outside is best but...). If you have the means, tuning the antenna in the place where it will transmit from is best (if the antenna can be tuned). yes wandered waaay off topic

I have done a bunch of university team inspections and they do not seem to know about the "magic" of RF. Buried antennas in the ebay, right next to the support rods, right next to the GPS antenna, need a whole class on that.

I have found that once on the ground, along with what Cris said in the air, is you have about 2-3 times the distance to get something (favoring 70cm). Receiver sensitivity and antenna are big factors here.

David
The 900 MHz transmitter is compatible with the current Eggtimer GPS receiver equipment.
 

cerving

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I've had a few people ask for a picture of the bottom (where most of the components are), so here it is. It's similar to a Proton in parts count. We got a shipping notice for the PC boards, so assuming that our shipment of RF modules comes in as expected we should be able to ship these out around the end of November.

thumbnail_IMG_4714a.jpg
 

Thorfire

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Is this able to record GPS data (internally or on an add-on board)? Asking before I order one in the next day or two.
 

heada

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Is this able to record GPS data (internally or on an add-on board)? Asking before I order one in the next day or two.
I ordered 2 Quasars with the OpenLog option. OpenLog is an add on board that writes the data output to a microSD card. From the holiday sale page:

OpenLog datalogger for TX/Quasar, $12

Edit: Here is some text from the Quasar page

What data does it collect?

The Quasar collects real-time altitude, velocity, and “milestone” events (i.e. launch detect, deployments). This is pretty typical of recording altimeters. By default, on the way up it samples at 20 times per second and on the way down it sample as 2 times per second. These rates are configurable in the Settings screen. The Quasar saves your last 14 flights, on a rotating basis. There are also pads to connect an OpenLog datalogger to capture the GPS/telemetry data, which can be imported into Google Earth or similar programs after the flight.
 
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DarthMuffin

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Can you post the PCB dimensions, mounting hole spacing and size, and approx antenna length (70cm)? I'd like to get a head start designing a 3d printed bay.

Thanks.

I've had a few people ask for a picture of the bottom (where most of the components are), so here it is. It's similar to a Proton in parts count. We got a shipping notice for the PC boards, so assuming that our shipment of RF modules comes in as expected we should be able to ship these out around the end of November.

View attachment 546703
 

cerving

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I'll see what I can do, but it may be a few days. I'm really busy just trying to catch up with invoicing and shipping what we have in stock.
 

A-ron

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The assembly guide is now on the Eggtimer Rocketry web site...

Very nice design!

The only things I would change about the Quasar is to refactor it into a two-board solution and add a dual-battery option. A KiCAD project for a rainy day, maybe.

Suggestion Box: It would be nice to be able to use an Eggfinder TX/Mini as a telemetry module for the Quark, Quantum and Proton.
 

StreuB1

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Placed a large order with Cris yesterday and one of the items is a 70cm Quasar setup for a 2023 Balls shot.

Can't wait to try it out. Also have some Quantums and a few Apogees coming as well.

Really looking forward to expanding my electronics kit and trying out more of Cris' handiwork!!

We'll be trying out the Quantum and Quasar on some staging duties in the spring. Lots to look forward to in 2023!

Thanks Cris!!!!
 

Rustoleum

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Looking forward to building some Quasars and a Ground Station when they Arrive.

Already received some Quantum's to solder up between Christmas and New Year's.
 

DarthMuffin

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FYI, TRS vs Quasar comparison. For anyone 3d printing something, the mounting holes are 3.15mm (I think instructions say #4 screw, I'm going to use m3 nylon screws because I have a ton). About 22.75 x 92mm on center. You'll need 4mm standoffs, 3mm if you don't need the antenna to clear (if it sticks past your mount).
trs vs quasar.jpg
 
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