I could use some help please

teepot

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After 8 months of back and forth with MCTronics I have a partially assembled Eggfinder GPS system. The boards are all assembled and some components are in the hand held box. If one of you nice TRF'ers would like to finish the assembly I will gladly pay you. At this point the cost of the assembly is the least of my worries. PM me if your interested. Thank you in advance. If you would like to hear my tale of whoa PM me.

Dave
 

heada

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Are you having issues with the flight electronics or with the base station? Flight electronics are fairly easy. Making the base station is fairly easy too but stuffing it all into the handheld station is a pain.

I've done several TRS and minis if you need help with that. Only done 1 base station and could solder another up but stuffing it into the handheld station I'll pass on since I'd probably screw it up for you.
 

KenECoyote

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Are you having issues with the flight electronics or with the base station? Flight electronics are fairly easy. Making the base station is fairly easy too but stuffing it all into the handheld station is a pain.

I've done several TRS and minis if you need help with that. Only done 1 base station and could solder another up but stuffing it into the handheld station I'll pass on since I'd probably screw it up for you.
Actually I thought the handheld case was much roomier than the custom Tri-corder case I made for the early version of Eggfinder back ~2015...
View attachment VID_20220628_194536530.mp4
IMG_20220628_194238800_HDR.jpg
😁
 

hobie1dog

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I have a local flier who has offered to assemble the LCD receiver and put it in their case for me, and the GPS transmitter that goes with it. It says that it provides an arrow in the screen showing the direction. ?? I still don't quite understand how the 70cm ham radio unit works, as I have a 2m/440 Kenwood G71 handheld radio, but it doesn't have GPS in it, so I assume you have to use a HT radio with GPS in it? and if you do, why would you have to use their receiver? Yes, I'm not intelligent
 

Sooner Boomer

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According to the Eggtimer web site, the GPS transmitter works on 900MHz. The LCD receiver picks up this signal, and (w/o add-on) will display the coordinates of the rocket (transmtter). If you add on the LED-GPS module, it knows where the receiver is, too, and can point you in the direction of the rocket. You don't need an additional receiver.
 

KenECoyote

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I have a local flier who has offered to assemble the LCD receiver and put it in their case for me, and the GPS transmitter that goes with it. It says that it provides an arrow in the screen showing the direction. ?? I still don't quite understand how the 70cm ham radio unit works, as I have a 2m/440 Kenwood G71 handheld radio, but it doesn't have GPS in it, so I assume you have to use a HT radio with GPS in it? and if you do, why would you have to use their receiver? Yes, I'm not intelligent
Eggfinder is actually available as GPS or Ham license. GPS doesn't require anything (similar to a car's gps). The Ham one I know nothing about (see... I'm NOT a know-it-all 😆), but I'd guess works like the Altus Metrum stuff
 

hobie1dog

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Eggfinder is actually available as GPS or Ham license. GPS doesn't require anything (similar to a car's gps). The Ham one I know nothing about (see... I'm NOT a know-it-all 😆), but I'd guess works like the Altus Metrum stuff
Well I will need to find out how the ham version works first before spending any of my hard to get money
 

waltr

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Eggfinder is actually available as GPS or Ham license. GPS doesn't require anything (similar to a car's gps). The Ham one I know nothing about (see... I'm NOT a know-it-all 😆), but I'd guess works like the Altus Metrum stuff

This does not make sense....

All Eggfinders have a GPS module. This does the receiving of the GPS satellites and calculates the 3D coordinates and outputs results in NMEA text strings.

Next is the RF (radio) link from the airborne Eggfinder to the Ground station (the LCD Reciever). there are two Options:
1- 915MHz no license band
2- 70cm (435MHz) Ham Radio band requiring a license.
Both of these work the same as to using the LCD Receiver. Only difference is the 70cm Ham version has a greater range (may be desired if flying very, very high and expect landing miles away).

Other options are in the LCD Receiver box. These are:
1- BlueTooth RF module to send the GPS NMEA strings to a smart phone or Laptop.
2- Another GPS module to locate the LCD box and show arrow and bearing from LCD Receiver to the rocket.
3- A Voice module for the LCD Receiver (could be handy if need to drive to landing location).

Then there is a simple 915MHz RX with a serial USB cable to send NMEA stings to a laptop.
With this RX the Laptop must run software to show rockets location on a map and/or display the Lat & Long.

All this is here:
 

KenECoyote

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This does not make sense....

All Eggfinders have a GPS module. This does the receiving of the GPS satellites and calculates the 3D coordinates and outputs results in NMEA text strings.

Next is the RF (radio) link from the airborne Eggfinder to the Ground station (the LCD Reciever). there are two Options:
1- 915MHz no license band
2- 70cm (435MHz) Ham Radio band requiring a license.
Both of these work the same as to using the LCD Receiver. Only difference is the 70cm Ham version has a greater range (may be desired if flying very, very high and expect landing miles away).

Other options are in the LCD Receiver box. These are:
1- BlueTooth RF module to send the GPS NMEA strings to a smart phone or Laptop.
2- Another GPS module to locate the LCD box and show arrow and bearing from LCD Receiver to the rocket.
3- A Voice module for the LCD Receiver (could be handy if need to drive to landing location).

Then there is a simple 915MHz RX with a serial USB cable to send NMEA stings to a laptop.
With this RX the Laptop must run software to show rockets location on a map and/or display the Lat & Long.

All this is here:
Screenshot_20220630-063625-821.png

Actually, maybe it's only the TRS, which I last assembled. My guess is that it has a version which transmits on Ham frequency vs. regular radio (?) frequencies around 915mhz. The reciever also comes in Ham version, which is something I saw even before getting a TRS.
Screenshot_20220630-064714-537.png
 
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Grant_Edwards

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441799-0cabe0b3161e0474cc43efe7fa957f29.png

The receiver requires a HAM license?

Have the FCC rules changed since I was a Ham (several decades ago)?

Or was I wrong in my understanding that the FCC rules allowed anybody to own/operate a HAM band receiver?
 

Grant_Edwards

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It is not the HAM version.
I'm sorry, I don't know what "it" refers to above or how it relates to my question.

There are two versions.
I know that there are two versions. The screenshot in my post says that the 70cm version of the receiver requires a Ham license. Back when I was a Ham (admittedly a long time ago) I'm quite sure that was not true: no license was required to own/operate a Ham band receiver. Only transmitting required a license.

Hence my question:

Have the FCC rules changed so that receivers now require licenses?
 

heada

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The hand-held device has the ability to transmit as well I think. Since it is transmitting on 70cm you have to have a FCC license, no?
 

cerving

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The 70cm units are only available for use with the Eggtimer TRS or the Eggtimer Telemetry Module when used with an Eggtimer Quantum or Proton. altimeter. You need to have an FCC Ham license to use them. The "dumb" transmitters (Eggfinder TX/Mini) do not have the capability to send out the required Ham call sign, and neither does the Quark altimeter. Most flyers will be fine with the license-free 900 MHz units... I have personally tracked rockets to over 6 miles with the 900 MHz units, and I have heard anecdotal accounts of them going to a lot farther than that.
 

Grant_Edwards

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The hand-held device has the ability to transmit as well I think. Since it is transmitting on 70cm you have to have a FCC license, no?
If it transmits on 70cm, then yes you need a license. I see no indication in any of the Eggtimer LCD Reciever documentation that it transmits on 70cm. It will transmit using Bluetooth (with an add-on module), but that doesn't require a license.
 

Grant_Edwards

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The 70cm units are only available for use with the Eggtimer TRS or the Eggtimer Telemetry Module when used with an Eggtimer Quantum or Proton. altimeter. You need to have an FCC Ham license to use them.

People seem to be reading way more into my question than I intend. I'm not asking about the transmitters.

Of course you need a Ham license to operate a 70cm transmitter, I'm not questioning that.

My question is: does the FCC require a Ham license for a 70cm receiver?

Or does the 70cm Eggfinder LCD Receiver also transmit on 70cm as heada stated above? [And therefore it requires a Ham license.]

Buying, building and operating a 70cm Eggfinder LCD Receiver without also operating a corresponding 70cm transmitter obviously makes little practical sense. I'm asking if from a purely academic, regulatory standpoint are you legally allowed to operate the 70cm receiver without a Ham license?

I suppose in theory, the transmitters being used could be operated by somebody else with a Ham license, with the receiver being operated by a non-licensed person — an improbable situation which would render my question not-quite-entirely moot. :)
 

waltr

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But what good is a receiver without a matching Transmitter???

You need the SYSTEM, RX + TX for it to be useable.
 

Grant_Edwards

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But what good is a receiver without a matching Transmitter?

I'm not asking about usefulness. I'm asking about FCC regulations.

You need the SYSTEM, RX + TX for it to be usable.

Yes, I know.

When I asked if a Ham license was required for the 70cm receiver, all I wanted to know was whether the FCC requires a Ham license to operate the 70cm receiver.

I'm not asking or implying about its usefulness, I don't mean to imply that I want or plan to do it, that somebody else should do it, or anything else.

I'm asking a very simple question, which should be interpreted 100% literally:

Does the FCC require a Ham license to operate a Ham band receiver?

Back when I was a Ham many decades ago, that was not the case. I was wondering if the FCC regulations have changed so that a Ham license is now required to operate a 70cm receiver.
 

waltr

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Does the FCC require a Ham license to operate a Ham band receiver?
No license needed for just a Receiver.

Can the Eggfind RF module in the LCD Receiver transmit?
Yes, both the airborn and LCD RX use the "Hope RF HM-TRP RF module".

This module is a Transceiver Therefore an FCC license is required for the 70cm version for what at first glance looks like 'just a receiver'.
 

heada

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The same hand-held receiver is used by all 3 GPS products; finder, finder mini and TRS. For the TRS, the hand-held receiver can transmit to the TRS for things like testing deployment channels and pre-flight configuration.

Since it does both, transmit and receive, if you get the 70cm version, you must be a ham.
 

Grant_Edwards

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The same hand-held receiver is used by all 3 GPS products; finder, finder mini and TRS. For the TRS, the hand-held receiver can transmit to the TRS for things like testing deployment channels and pre-flight configuration.

Since it does both, transmit and receive, if you get the 70cm version, you must be a ham.

Thanks for the explanation. That's indeed why the 70cm "receiver" requires a license: it's a transceiver.
 

msjohnso

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Worthy of note: Getting a ham license isn't all that difficult these days. Just about every major city (and a lot of less-than-major ones) have a radio club that serves as a volunteer examiner for all classes of license. The entry-level Technician class license has 35 questions and requires about a 70% grade to pass. Questions cover radio law and basic electronic theory; the exams are created dynamically from a question pool available from the FCC or many online sources. Study books for all levels of license exam can be had from numerous sources and are not prohibitively expensive.

Everything you are likely to want to do with amateur radio and rocketry (in terms of radiolocation and telemetry, for sure) can be done with the Technician grade license privileges. Morse code proficiency has not been required for some years, but the FCC did re-instate license fees ($35 for 10 years) a few months ago. Still quite a bargain.

Check out arrl.org or just google 'amateur radio' and you will be drowned in information. Most of it is even useful.

Mark J
Amateur radio WB9QLR, since 1975
 
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