Introducing the Eggtimer LR-Series GPS/Telemetry Systems
Eggtimer Rocketry is proud to announce the Eggtimer LR-Series of GPS tracker and telemetry systems. The LR-Series uses LoRa technology to give you extended range and a more reliable data link compared to the previous digital technology. You will also get a lot more unique transmission settings to help prevent conflicts at large launches. They will be replacing the existing Hope RF-based products within the next few months… our target release is by the end of 2026.
Why are you replacing your existing GPS/telemetry systems?
The Hope RF radios that we’ve been using since 2014 have become increasingly more difficult to obtain in the past few years. Although they technically are still available, we see the writing on the wall and have pretty much been forced to look for an alternative.
Will the new GPS/telemetry transmitters and receivers be compatible with older Eggtimer Rocketry gear?
Unfortunately, no. The Hope RF radios and the LoRa radios in the new LR systems are on different base frequencies and use different modulation techniques. But, that also means that they can coexist together in the same rocket with essentially no degradation in performance from either one.
Will I still be able to obtain the older gear? I have some already and I’d like more…
We have a decent supply of the Hope RF radios, but in some cases it’s the PC boards that we have on hand that is the constraint. We will still have them on sale during our annual Holiday Sale in November, but once they’re gone, that’s it. BTW, we also intend to have the LR systems on sale too… although you may have to wait a month or so for delivery.
I have a lot of the existing Eggtimer GPS/telemetry gear, will it be obsolete?
We will continue to sell the Hope RF based gear as long as we have the parts, and we will support it as long as we’re in business. That should be a LONG time…
That being said, if you want more of the current products it would be prudent to buy them sooner rather than later, while we still have them. Some products will be in very short supply.
I don’t have any Eggtimer GPS/telemetry products yet, but I’m thinking about it. Should I order the current ones or wait for the new LR ones?
We’ll be honest… if that’s your situation, wait. We’d love to take your money now, but we don’t want you to be unhappy in a year or two if you can’t get another transmitter and have to buy all new gear. We’ve been selling the Hope RF-based systems for over 12 years, we expect to get another 12 years out of the new LR systems.
Will the new LR GPS/telemetry gear cost more?
In most cases, no. We try very hard to make our products as affordable as possible. And in some cases, you’ll find that they actually cost less than the equivalent existing products, because they will all ship with external antennas rather than simple wire antennas.
Will the new LR systems be compatible with Brand X’s LoRa gear?
Probably not. The frequency and modulation settings we’re using are different than that of existing rocketry LoRa systems, so our receiver won’t pick up their transmitters and their receivers won’t pick up ours. But, that is by design… we want you to be able to mix and match gear in your rockets without worrying about them conflicting. We have flown rockets with both our LoRa gear and Brand X’s only a few inches away from each other, with no apparent ill effects on either one. We have also bench-tested them with a spectrum analyzer to confirm that they don’t conflict.
Will the new LR systems have the same range as the old gear?
Yes, at the very least, and in some cases the range can be much higher. In particular, the new TX-LR and Quasar-LR transmitters will have settings that should extend the range to close to 100,000’. That’s based on the current TX having a range of about 30,000’… you can probably get more than that out of it.
The Mini-LR and the Eggtimer Telemetry Module LR will have similar range to the existing units (around 20,000’), since they have similar RF output power. Those devices will also have reduced-power settings that saves battery life if you don’t need the full power (i.e. if you’re using an ETM in an EZ-DD rocket that’s going to 2,000’ you do not need 30,000’ of range).
How much RF output power do the new LR transmitters have?
The TX-LR will go up to 1W, the Quasar-LR will go up to 500 mW, and the Mini-LR and ETM-LR will go to about 150 mW. That is the maximum setting… the default on them is going to be the minimum power settings, since you’ll have to test them after you build them anyway. After testing, you can set the Frequency, ID, Power, and AirData rates to whatever is appropriate.
How many different settings will the new LR transmitters support?
It depends on which transmitter, but in general you will have 25 base frequencies, 20 ID codes, and at least two data rates. Those three parameters make the transmission unique… if any one of those three is changed, a receiver set to the other two will not read the data. That’s 1,000 different settings.
Note that the RF power output setting does NOT affect the uniqueness of the data transmission.
What kind of battery power will the new LR transmitters use?
The TX-LR and the Quasar-LR will require a 2S Lipo battery, just like their predecessors did. The capacity that you need will depend on the radio settings… in general, lower RF power and higher data rates will take less battery power, and conversely higher RF power with lower data rates (which increase range) will draw more battery power. In some cases, a LOT more power… the instructions will have charts that illustrate the differences in battery draw at different radio settings. Obviously, a TX-LR transmitting at 1W is going to draw a lot more battery power than one transmitting at 125 mW.
To give you an idea, the current TX transmitter rated at 100 mW of RF output power draws about 85 mA on average, the new TX-LR will draw about 120 mA with similar settings but will provide about 30% more range. If you’ve been using a 500 mAH 2S Lipo battery for your TX (a pretty typical capacity…), it should be fine for the new one too.
The Mini-LR will operate with a 1S or 2S battery, just like the current one, and the ETM-LR will use the 3.3V output from your altimeter, again just like the existing units. The LCD-LR receiver will require a 2S Lipo battery… again, just like what we have now.
Operationally, how will they work compared to the existing gear?
Operation will be nearly identical, if you’ve used an Eggtimer LCD receiver before you won’t even know the difference. You’ll use the LCD-LR receiver to display the data from the transmitter, and the existing LCD-GPS Module and Voice Module will both the compatible with the LCD-LR receiver. Like the existing systems, you’ll change the radio parameters of the transmitters by connecting them to the LCD-LR receiver and programming the receiver (except for the Quasar-LR, which has those settings in its browser menus).
Honestly, making them as much like the current system as possible benefits both us and existing users. It makes our development process easier, and for YOU it makes using them easier because it’s just like what you are already using… the changes are all on the back end and essentially invisible to you.
How do they compare size-wise?
All of them have about the same footprint as the current transmitters, although they are a few mm taller because the radio module is a through-hole part in a shielded metal can rather than a surface mount “stamp” part. That actually makes it MUCH easier to build… and greatly reduces the chance of shorts between the pads, which was always an issue with the Hope RF part.
The Quasar-LR will be a stacked-board format… the footprint is the same, but it has two circuit boards stacked about 6mm apart. This is due to the larger format of the LoRa radio, and because the radio has its own power supply.