Help Support RocketryForum by donating using the link above or becoming a Supporting Member.


Results 1 to 25 of 25
  1. #1
    Join Date
    22nd February 2013
    Location
    Garland, TX
    Posts
    3,646

    Nose Cone and Shockcord Mount for TeleGPS - Available

    EDIT: See post 14 regarding availability

    Several people contacted me about a sled for the TeleGPS similar to those for the Eggfinder, Eggfinder mini and MWT3, so when I found out a rocket buddy got a TeleGPS I had to hit him to borrow his tracker for a bit. He graciously loaned me his tracker and battery (Thanks Jeff). After an embarrassing amount of tries I have a sled that is strong, fits the largest LiPo (850 mAh) Altus Metrum sells (as well as many others), and works with the same mounting dodads as my other sleds.



    Everything mounts up with 4 screws and 2 zip ties...one to hold the battery, and one to provide extra antenna support. The battery is held laterally by the sides in the case of the 850 mAh battery, but there is a zip tie pass through to secure narrower batteries.

    This sled uses the same 1/4-20 nut capture as the others for a mounting point.



    It works with the same 38mm nosecone bulkhead as the other sleds for nose cone mounting (show here with drill guide and set screws).



    There is also a shell (not the same as the EFmini) to allow for shock cord attachment (shown here with screws).


    Last edited by Cl(VII); 28th November 2017 at 06:51 AM.
    So much of my rocket building time has been diverted toward my "other hobby": Race Timing

  2. #2
    Join Date
    29th May 2015
    Location
    Keller, Texas
    Posts
    618
    Not that I had any doubts but that turned out great Chris, nice job. Looks like the lead on the battery is about the perfect length to tuck away nicely.

    Jeff Jones

    TRA 04736
    NAR 75968
    L3 KF5YYI




  3. #3
    Join Date
    22nd February 2013
    Location
    Garland, TX
    Posts
    3,646
    Quote Originally Posted by PokerJones View Post
    Not that I had any doubts but that turned out great Chris, nice job. Looks like the lead on the battery is about the perfect length to tuck away nicely.
    Thanks Jeff. Also, thanks again for the loan of the TeleGPS and battery. Gotta say, that 29mm wide battery gave me fits.

    Also, I didn't realize my Yaesu FT2DR would directly receive the coordinates from the TeleGPS. I though you needed a Tele-thingy to decode everything. I know you don't get as rich a data, but finding the rocket is what I'm after. Need to add one of these as a tiny backup tracker to move between rockets.
    Last edited by Cl(VII); 27th November 2017 at 04:52 AM.
    So much of my rocket building time has been diverted toward my "other hobby": Race Timing

  4. #4
    Join Date
    20th February 2009
    Location
    Cayuga, Indiana
    Posts
    12,828
    Where can I purchase this?

    From the Ether...
    L3, TRA #11847
    Tripoli Indiana #132
    Tripoli Central Illinois #59
    Central Illinois Aerospace (NAR) #527
    Chicago Rocket Mafia, "Big Bucks" Dixon
    ___________________________________

    Quiet little voices creep into my head. -- We Were Promised Jetpacks

  5. #5
    Join Date
    22nd February 2013
    Location
    Garland, TX
    Posts
    3,646
    Quote Originally Posted by dixontj93060 View Post
    Where can I purchase this?

    From the Ether...
    Give me a few days. I need to do some boring stuff, like batch printing to figure out final print times and ensure consistency. Thanks for asking though.
    So much of my rocket building time has been diverted toward my "other hobby": Race Timing

  6. #6
    Join Date
    26th November 2009
    Posts
    4,712
    Quote Originally Posted by Cl(VII) View Post
    Thanks Jeff. Also, thanks again for the loan of the TeleGPS and battery. Gotta say, that 29mm wide battery gave me fits.

    Also, I didn't realize my Yaesu FT2DR would directly receive the coordinates from the TeleGPS. I though you needed a Tele-thingy to decode everything. I know you don't get as rich a data, but finding the rocket is what I'm after. Need to add one of these as a tiny backup tracker to move between rockets.
    That's the thing with the Tele-Mega and Tele-GPS. They can be programmed to send APRS positions so one wouldn't
    have to use a Tele-BT. Some of the live in Flight data wouldn't he had but one could simply download it once they recover the device. Kurt

  7. #7
    Join Date
    22nd February 2013
    Location
    Garland, TX
    Posts
    3,646
    Quote Originally Posted by ksaves2 View Post
    That's the thing with the Tele-Mega and Tele-GPS. They can be programmed to send APRS positions so one wouldn't
    have to use a Tele-BT. Some of the live in Flight data wouldn't he had but one could simply download it once they recover the device. Kurt
    I just plugged it in, and turned my B channel to the frequency and started getting coordinates. Really straight forward.
    So much of my rocket building time has been diverted toward my "other hobby": Race Timing

  8. #8
    Join Date
    26th November 2009
    Posts
    4,712
    Quote Originally Posted by Cl(VII) View Post
    I just plugged it in, and turned my B channel to the frequency and started getting coordinates. Really straight forward.
    I think there is a programming option to "turn on" the APRS packet that is transmitted with the Altus encoded flight data or turn off APRS in the software. A fellow posted if APRS is turned off, it lowers the power consumption. I haven't messed with
    the programming on my Tele-GPS for ages as once on, I want to be be able to use either. Kurt

  9. #9
    Join Date
    21st January 2017
    Location
    Wichita KS
    Posts
    95
    Chris, I don't mean to derail your thread, but I'm curious about the picture with the nose cones. It appears the antenna gets crammed in and squished. Kurt, what are your thoughts on the antenna in that picture?

    I've got a TeleGPS that I want to fit into a Mongoose 38 nose cone which is about the same size as those, and I've been wondering about coiling the antenna around a mandrel to reduce the footprint without actually changing the length. I just don't know how sensitive 70cm is to coil vs straight for a given length. I do wish the Altus Metrum guys had some different antenna options for this thing.

    edit: If it's worth a whole 'nuther thread, I don't mind deleting the post here so your thread doesn't get off track.

  10. #10
    Join Date
    22nd February 2013
    Location
    Garland, TX
    Posts
    3,646
    Quote Originally Posted by AeroAggie View Post
    Chris, I don't mean to derail your thread, but I'm curious about the picture with the nose cones. It appears the antenna gets crammed in and squished. Kurt, what are your thoughts on the antenna in that picture?

    I've got a TeleGPS that I want to fit into a Mongoose 38 nose cone which is about the same size as those, and I've been wondering about coiling the antenna around a mandrel to reduce the footprint without actually changing the length. I just don't know how sensitive 70cm is to coil vs straight for a given length. I do wish the Altus Metrum guys had some different antenna options for this thing.

    edit: If it's worth a whole 'nuther thread, I don't mind deleting the post here so your thread doesn't get off track.
    I'm with you in that I don't know how much the antenna bending effects range. I suspect it isn't practically too terrible given the level of overkill the transmitter is in a 38mm. Short of a multistage project getting a 38 much over 20k is gonna be rare. This is of course just a feeling as I have no data to back it up.
    So much of my rocket building time has been diverted toward my "other hobby": Race Timing

  11. #11
    Join Date
    29th May 2015
    Location
    Keller, Texas
    Posts
    618
    Quote Originally Posted by AeroAggie View Post
    Chris, I don't mean to derail your thread, but I'm curious about the picture with the nose cones. It appears the antenna gets crammed in and squished. Kurt, what are your thoughts on the antenna in that picture?
    . I do wish the Altus Metrum guys had some different antenna options for this thing.
    .
    Altus Metrum also sells an rp-sma edge connector (available almost anywhere) you can solder on to the board after removing the whip antenna so you can use a small 70cm HT antenna. I have a 8" diamond antenna and 4" comet that I intend to use with the TeleGPS after a little testing on strength and range.

    https://www.ebay.com/itm/COMET-MH-51...53.m1438.l2649

    https://www.gigaparts.com/diamond-antenna-srh519.html
    Last edited by PokerJones; 28th November 2017 at 05:34 AM.
    Jeff Jones

    TRA 04736
    NAR 75968
    L3 KF5YYI




  12. #12
    Join Date
    7th July 2013
    Location
    Toronto
    Posts
    3,224
    Quote Originally Posted by PokerJones View Post
    Altus Metrum also sells an rp-sma edge connector (available almost anywhere) you can solder on to the board after removing the whip antenna so you can use a small 70cm HT antenna. I have a 8" diamond antenna and 4" comet that I intend to use with the TeleGPS after a little testing on strength and range.

    https://www.ebay.com/itm/COMET-MH-51...53.m1438.l2649

    https://www.gigaparts.com/diamond-antenna-srh519.html
    I have several TeleGPS units and have pretty much just zip tied the stock antenna to a G10 board, but I would like to hear more about these antenna options. Do you have any idea on the performance, as compared to the stock antenna? My experience with the stock, using a 3 element Yagi, is lock (except for Mach) to just over 22,000 AGL, and 3.5 miles on the ground.
    Michael Pitfield
    TRA 14579 L2
    NAPAS BoD
    URRG
    MARS
    CRC

  13. #13
    Join Date
    22nd February 2013
    Location
    Garland, TX
    Posts
    3,646
    Quote Originally Posted by mpitfield View Post
    I have several TeleGPS units and have pretty much just zip tied the stock antenna to a G10 board, but I would like to hear more about these antenna options. Do you have any idea on the performance, as compared to the stock antenna? My experience with the stock, using a 3 element Yagi, is lock (except for Mach) to just over 22,000 AGL, and 3.5 miles on the ground.
    Did you loose lock at 22k, or is that as far as you have pushed one?
    So much of my rocket building time has been diverted toward my "other hobby": Race Timing

  14. #14
    Join Date
    22nd February 2013
    Location
    Garland, TX
    Posts
    3,646
    Quote Originally Posted by dixontj93060 View Post
    Where can I purchase this?

    From the Ether...
    I've worked out print times, and weights...came out very close to the EFmini, so these are now available as the below kits:

    1) The Shockcord Mount: Contains - (1) Sled, (1) Outer Shell, and (3) 4-40 screws - Price $21
    2) Nose Cone Mount: Contains - (1) Sled, (1) Bulkhead, (1) Drill Alignment Guide and (5) M4 set screws - Price $20
    3) The Works: Includes - (1) Sled, (1) Outer Shell, (1) Bulkhead, (1) Drill Guide, (3) 4-40 screws and (5) M4 Set Screws - Price $30
    4) Just The Sled - Price: $15

    Shipping $4 CONUS

    I have a few on hand, but after that these will be print to order until I can gauge interest. As always I will not invoice until your request is in hand. I'll also honor the same sale price through the end of the month on these as with the EF and EFmini sleds: 15% off, and free shipping over $25 (after discount).

    If you are interested PM me or email me: c_f_bender at hotmail -dot- com

    Include what you would like and your PayPal associated email.
    So much of my rocket building time has been diverted toward my "other hobby": Race Timing

  15. #15
    Join Date
    7th July 2013
    Location
    Toronto
    Posts
    3,224
    Quote Originally Posted by Cl(VII) View Post
    Did you loose lock at 22k, or is that as far as you have pushed one?
    There seems to be some GPS data loss when going transonic and through Mach, so far up to Mach 2.5, but it always gains lock as soon as it pops back into the transonic range. The down-link appears to track all the way up but I sens that there is some buffering and extrapolating going on.

    As far as performance and reliability, I have nothing but praise for the product, Bdale and Keith. It has been awesome so far and I have somewhere around a couple of dozen launches between the three units, all flawless.

    22K is as high as I have used it for tracking, and it is the highest AGL I have launched so far. I am hoping to add another 15K to that record in 2018 and plan on using the TeleGPS.

    Here is a pic of the sled from the nosecone of my Tomach, which also has a Comspec AT-2B mounted on the opposite side. The two units don't cause any noticeable interference with each other. I use the Comspec for backup, but I have never really needed it. I use it more for fun as well as testing my tracking skills, which is a bit of an art and something I work at getting better. The TeleGPS is so good and easy, I almost feel guilty as its a bit like cheating.

    Michael Pitfield
    TRA 14579 L2
    NAPAS BoD
    URRG
    MARS
    CRC

  16. #16
    Join Date
    22nd February 2013
    Location
    Garland, TX
    Posts
    3,646
    Quote Originally Posted by mpitfield View Post
    There seems to be some GPS data loss when going transonic and through Mach, so far up to Mach 2.5, but it always gains lock as soon as it pops back into the transonic range. The down-link appears to track all the way up but I sens that there is some buffering and extrapolating going on.

    As far as performance and reliability, I have nothing but praise for the product, Bdale and Keith. It has been awesome so far and I have somewhere around a couple of dozen launches between the three units, all flawless.

    22K is as high as I have used it for tracking, and it is the highest AGL I have launched so far. I am hoping to add another 15K to that record in 2018 and plan on using the TeleGPS.

    Here is a pic of the sled from the nosecone of my Tomach, which also has a Comspec AT-2B mounted on the opposite side. The two units don't cause any noticeable interference with each other. I use the Comspec for backup, but I have never really needed it. I use it more for fun as well as testing my tracking skills, which is a bit of an art and something I work at getting better. The TeleGPS is so good and easy, I almost feel guilty as its a bit like cheating.

    Cool, thanks for the clarification. The 3.5 miles on the ground is quite impressive also.
    So much of my rocket building time has been diverted toward my "other hobby": Race Timing

  17. #17
    Join Date
    7th July 2013
    Location
    Toronto
    Posts
    3,224
    Quote Originally Posted by Cl(VII) View Post
    The 3.5 miles on the ground is quite impressive also.
    Yeah that was a bit of a scare. I had a main deploy at apogee 16,400, primarily due to failed shear pins but there was more to it. I recovered it in an 8' corn field 3.46 miles from the pad, and on inspection my Loki 54-2800 case was a 1/4 turn from falling out. Ever since then I use some blue loctite when I screw my motor in.
    Michael Pitfield
    TRA 14579 L2
    NAPAS BoD
    URRG
    MARS
    CRC

  18. #18
    Join Date
    22nd February 2013
    Location
    Garland, TX
    Posts
    3,646
    Quote Originally Posted by mpitfield View Post
    Yeah that was a bit of a scare. I had a main deploy at apogee 16,400, primarily due to failed shear pins but there was more to it. I recovered it in an 8' corn field 3.46 miles from the pad, and on inspection my Loki 54-2800 case was a 1/4 turn from falling out. Ever since then I use some blue loctite when I screw my motor in.
    Definitely weren't getting that one back without a tracker.
    So much of my rocket building time has been diverted toward my "other hobby": Race Timing

  19. #19
    Join Date
    21st January 2017
    Location
    Wichita KS
    Posts
    95
    Quote Originally Posted by PokerJones View Post
    Altus Metrum also sells an rp-sma edge connector (available almost anywhere) you can solder on to the board after removing the whip antenna so you can use a small 70cm HT antenna. I have a 8" diamond antenna and 4" comet that I intend to use with the TeleGPS after a little testing on strength and range.

    https://www.ebay.com/itm/COMET-MH-51...53.m1438.l2649

    https://www.gigaparts.com/diamond-antenna-srh519.html
    Thanks for the info! I've already got some RP-SMA connectors leftover from converting my eggfinders and it just didn't dawn on me to try to convert my Tele too since it comes built that way. I didn't dig around on Altus Metrum store to see that they even offered those for the option. I'll be placing an order for an antenna as soon as I'm done typing this post...

  20. #20
    Join Date
    29th May 2015
    Location
    Keller, Texas
    Posts
    618
    Quote Originally Posted by mpitfield View Post
    I have several TeleGPS units and have pretty much just zip tied the stock antenna to a G10 board, but I would like to hear more about these antenna options. Do you have any idea on the performance, as compared to the stock antenna? My experience with the stock, using a 3 element Yagi, is lock (except for Mach) to just over 22,000 AGL, and 3.5 miles on the ground.
    Actually this is my first TeleGPS and have only flown it once with the stock wire antenna to about 4k'. I am going to solder on the sma connector and try it out this weekend for range with the other 70cm antennas I have.

    I also use the 3 element arrow yagi for this with the TeleBT attached and it worked well on the first flight. The yagi was actually sitting on a table about 20' away pointing in the general direction of the flight and I was getting a good signal the whole time so I want to see what kind of range I can get with an 8" HT antenna on the TeleBT for lower flights, obviously I would use the yagi for high altitude.
    Jeff Jones

    TRA 04736
    NAR 75968
    L3 KF5YYI




  21. #21
    Join Date
    8th October 2016
    Location
    Midwest
    Posts
    92
    Quote Originally Posted by mpitfield View Post
    There seems to be some GPS data loss when going transonic and through Mach, so far up to Mach 2.5, but it always gains lock as soon as it pops back into the transonic range. The down-link appears to track all the way up but I sens that there is some buffering and extrapolating going on.
    I believe that issue is do to Doppler shift of the radio signal. This phenomenon effects all forms of transmitted waves; sound, light and electromagnetic.

    Review the following:
    Electromagnetic radiation, the Doppler effect, exoplanets and cosmology.

    Wikipedia: Doppler effect

    The Doppler Effect for EM Waves [PDF]

  22. #22
    Join Date
    26th November 2009
    Posts
    4,712
    When I mentioned this in another thread people were like ????? The Doppler effect also affects/afflicts the receiver end.
    Also the speed and altitude limits hold for commercial GPS units and cannot be easily circumvented. Kurt

  23. #23
    Join Date
    19th February 2017
    Location
    The world, probably
    Posts
    346
    Quote Originally Posted by Tobor View Post
    I believe that issue is do to Doppler shift of the radio signal. This phenomenon effects all forms of transmitted waves; sound, light and electromagnetic.

    Review the following:
    Electromagnetic radiation, the Doppler effect, exoplanets and cosmology.

    Wikipedia: Doppler effect

    The Doppler Effect for EM Waves [PDF]
    While I agree that the Doppler effect affects all waves, I don't think that's the issue. A rocket going 1000m/s (mach 2.9ish) only has a 3kHz frequency shift for a 915MHz transmitter, which I would think would be pretty negligible. What I gather is that the GPS is having trouble getting enough readings in a given location to consider itself to have a reliable lock. More "aggressive" GPS modules that declare lock on fewer samples or less correlation between samples might work better at high speeds.

    Of course, I could be completely wrong, and modern radio chips are way pickier than I would expect.
    NAR #104043

    crmrc.org

  24. #24
    Join Date
    18th January 2009
    Location
    Savannnah, Ga
    Posts
    7,647
    Quote Originally Posted by AeroAggie View Post

    1. It appears the antenna gets crammed in and squished. Kurt, what are your thoughts on the antenna in that picture?

    2.I've been wondering about coiling the antenna around a mandrel to reduce the footprint without actually changing the length.
    1. this my sled for a 6 in.bay goes into this small 38mm rocket. You can see I had to bend heck out of antenna to make it fit. Rocket has gone to 18,000. Had a "booming" signal, with some loss. Still plenty to be usable, obviously enough for this flight

    Name:  DSCN5765.jpg
Views: 45
Size:  6.4 KB Name:  OI000012.jpg
Views: 45
Size:  7.1 KB

    You have a SS [signal strength] meter on the flight viewer, which allows testing of various antenna's . I have found the supplied wire does a better job than any of the small 'stub' versions I tested, which were rated +2db & +5db.
    Only better units I tried were wire whip 1/2 wave. Remember units of measuring are "db's' [decibel] . So if 1 antenna registers -44 and 2nd registers -41, a difference of -3... 2nd antenna [-41] has better range.

    Minus 41 is closer to "0" than -43 all this is counter intuitive, as we are used to higher number being better. [with negative numbers, lower is better!]
    With antennas it's opposite , don't forget that!

    Finally a difference of ONLY 3 db seems really small, it's huge. You must double the power to increase by 3, which also approximates double the range. [for simplicity here guys, I know this is close, not perfect.]

    So put your device at 100 ft away from base, have your flight viewer [AltosUI] open with SS running. You can see the signal strength. Swap out antenna's on both tracker & base to compare results. You will be surprised at the results
    I tested 6 different combinations of sizes and types. Flying to around 20,000 the simple supplied white wire worked better than several loaded black stubbies. Only ones that got better range were wire whips BP mounted and 1/2 wave.

    On Base, Yagi is the hands down best, BUT the 3 element not 7. 7 is too directional & you must be pointed directly at rocket.
    3 element is more forgiving and easier to use.

    BUT the simple wire or wire whip screwed on the base was ...way more sufficient for most of us. I sat it on hood of truck tracking to 36,000....booming signal all the way.

    Testing is simple, I would do so before changing antennas for use.

    2. You cannot simply coil antenna around an object and get good results[unless your stupid lucky...lol]
    Been studying this lately....there is a frequency specific [430's different than 900's] equation
    that relates to length [1/4 or 1/2 wave] number of coils & diameter of coils to get same or better range, by "loading" the antenna. You see this all the time on car/truck roof mounted antenna.

    I say try it, ya might get lucky & you can test with SS feature.
    Jim Hendricksen
    L-3 Tripoli 9693
    [ICBM, Orangeburg,SC R.I.P.] - QCRS ,Princeton ILL - MDRA , Price Maryland - Woosh, Bong Wisconsin- ROCC, Charlotte NC , ICBM Camden SC
    "Made" member of Chicago & Carolina Rocket Mafia
    Rocketry...........an exact science.......but not exactly !!!

  25. #25
    Join Date
    26th November 2009
    Posts
    4,712
    The problem with bending the antenna or paralleling metal all-thread is you just don't know without testing. Look at a Yagi antenna that is exploiting parallel chunks of metal to achieve "directivity" of the pattern.

    I would "cringe" at CJ's picture above but with a range test and perhaps the meter readings and the fact there was no other choice ya sometimes gotta go with
    what ya gots! (Keeping in mind that there is the risk of losing everything and the $400.00 investment in the TeleMega)

    If ya got a good signal with a wire on the receive end that's nice. Me, if I was there, I would'a yelled at ya and handed you my 7 element Arrow Yagi for
    insurance. Shows you how "chicken" I am! Kurt


Similar Threads

  1. Replies: 7
    Last Post: 31st August 2017, 04:48 PM
  2. Goblin nose cone, pre-packed with epoxy inside nose cone?
    By Vigilante_A-20_DEMON in forum Low Power Rocketry (LPR)
    Replies: 15
    Last Post: 21st October 2015, 03:23 AM
  3. Replies: 1
    Last Post: 22nd November 2013, 05:30 AM
  4. [For Sale] PML 11.4 Nose Cone, Tail Cone and Phenolic Tube
    By kly999 in forum Yard Sale / Wanted
    Replies: 3
    Last Post: 24th August 2011, 11:02 PM
  5. LOC shockcord mount question.
    By arthur dent in forum Recovery
    Replies: 8
    Last Post: 21st June 2006, 07:54 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •