EEVblog #721 - Globalstar Satellite Phone Teardown - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: March 05, 2015, 04:11:35 am
content: What's inside a 2000 vintage Globalstar GSP1600 Tri-Band Satellite Phone?Behold the Erectile Antenna, a helical designed extending antenna.Thanks to: Electronics Responsible Recyclers:http://er2.com/DSP:http://www.analog.com/media/en/technical-documentation/data-sheets/ADSP-2185.pdfIntel 386EX Embedded Processor:http://pdf.datasheetcatalog.com/datasheets2/78/784732_1.pdf

author: Stonent
author_rank: Super Contributor
timestamp: March 05, 2015, 05:22:25 am
content: I remember seeing the GlobalStar commercials when it first came out. I remember one where it showed someone climbing a mountain and it shows him standing on top. There was a voice-over that said something like "Out of phone range? Out of cell range? Now entering GlobalStar range." and then it shows him talking on the phone.I'm still watching the video but if it works when you're done taking it apart, try dialing 611 on it. That's customer service for most US mobile phones. If the phone isn't activated it will usually just offer start a new line of service.Since it has ESN numbers on the back it's probably a CDMA phone. It would probably roam onto Verizon or Sprint in the US.Yup, I was right:https://www.globalstar.com/shop/index.php?main_page=product_info&products_id=99QuoteGSM didn't really catch on in the US until the early 2000s. Before that it was Analog (AMPS), CDMA (IS-95), iDEN (Motorola) and TDMA (IS-136).AT&T and SouthWestern Bell (aka SBC) provided AMPS/TDMA service in my area.PrimeCo, GTE (later known as Verizon) and Sprint were the major AMPS/CDMA carriers.Nextel and SouthernLinc were iDEN carriers.VoiceStream was the first national GSM carrier in the US, but shortly after it started, it was bought by Deutsche Telekom AG and renamed T-Mobile USA.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: March 05, 2015, 06:02:57 am
content: The instruction on the right of the sticker further lends itself well for bad jokes.

author: miguelvp
author_rank: Super Contributor
timestamp: March 05, 2015, 06:09:59 am
content: Quote from: nitro2k01 on March 05, 2015, 06:02:57 amLike what? Do not pull or push or it might become permanently erect or suffer ED?

author: Stonent
author_rank: Super Contributor
timestamp: March 05, 2015, 06:10:06 am
content: Quote from: nitro2k01 on March 05, 2015, 06:02:57 amPerhaps the designer is related to the engineer who designed the Dallas/Fort Worth highway system. (And no, I didn't purposely darken those lines. Every map is like that )

author: austinhmfic
author_rank: Newbie
timestamp: March 05, 2015, 06:54:48 am
content: Answering Dave's erectile antenna patent challenge -- traced back from Qualcomm US patent#6,720,929which references a number of previous revisions starting from the early/mid 1990's with the idea of "A novel antenna assembly is created wherein the radiating portion is elevated above the handset by combining a half wavelength sleeve dipole antenna with a coaxial line section followed by a quarter wavelength choke" originating from AT&T on patent #5,440,317

author: PinheadBE
author_rank: Regular Contributor
timestamp: March 05, 2015, 08:41:31 am
content: Dave, you did it again.....I already told you: don't drink and blog...So, tell me again: where's your left hand and where's your right hand ? (4:08 and on)And, yeah... that's it: "Ethyl RF", as in "Ethylic" perhaps ?

author: nitro2k01
author_rank: Frequent Contributor
timestamp: March 05, 2015, 08:52:07 am
content: Quote from: PinheadBE on March 05, 2015, 08:41:31 amHmm, same mistake as Bush did. Though is it really a mistake? Perhaps when you're facing a camera as a professional, you're subconsciously imagining the viewer's left and right.Also, I'm noticing, a Seppy cameo in the previous blog, a Seppy cameo in the latest EEVBlog2 video, but no cameo in this video, unless I missed it...

author: Fungus
author_rank: Super Contributor
timestamp: March 05, 2015, 09:45:24 am
content: Weird that there's very little coverage over the sea, that most voice coverage is concentrated where regular cellphone coverage is good.I would have thought a major market for these 'phones would be people with boats.

author: Fungus
author_rank: Super Contributor
timestamp: March 05, 2015, 10:40:43 am
content: "Ethel" (the girl's name) doesn't have a 'y':http://en.wikipedia.org/wiki/Ethel"Ethyl" is something to do with chemistry:http://en.wikipedia.org/w/index.php?title=Ethyl

author: Howardlong
author_rank: Super Contributor
timestamp: March 05, 2015, 11:38:39 am
content: Quote from: Fungus on March 05, 2015, 09:45:24 amI would imagine that the coverage limitation is due to location of and co-visibilty with groundstation base stations bearing in mind the altitude of the orbit, limiting the satellites' footprints.Using LEO means the path loss is limited and the handsets can be small, ie you don't need large antennas with high gain and/or high power RF amplifiers.

author: Stonent
author_rank: Super Contributor
timestamp: March 05, 2015, 11:41:14 am
content: Quote from: Fungus on March 05, 2015, 10:40:43 amIn the US years ago Ethyl was a term used for Gasoline with Tetra Ethyl Lead in it.Also the Ethyl Corporation was a company that manufactured that chemical.http://en.m.wikipedia.org/wiki/Ethyl_Corporation

author: Tek_TDS220
author_rank: Regular Contributor
timestamp: March 05, 2015, 04:08:03 pm
content: I was fascinated by the helical receive/transmit antenna with integrated balun. Very cool engineering and physics!Also, I was surprised by the i386 processor. There must be a story behind that. It appears that Qualcomm didn't get into the processor business until 2008 when they introduced their first ARM processor.Finally, when my first daughter was born, I proposed to my wife to name her Ethyl. The second girl would be Methyl. My wife didn't think this was a good idea.

author: N2IXK
author_rank: Frequent Contributor
timestamp: March 05, 2015, 04:31:28 pm
content: QuoteBut Methyl should be the first (CH3), followed by Ethyl (C2H5), then Propyl (C3H7).

author: German_EE
author_rank: Super Contributor
timestamp: March 05, 2015, 04:39:29 pm
content: I have always wondered with those RF assemblies, do they design the PCB then order shielding cans to fit or do they purchase standard size shielding cans then design the PCB sections to fit inside them?

author: SeanB
author_rank: Super Contributor
timestamp: March 05, 2015, 04:42:28 pm
content: The multipin connector is there to support a full RS232 data link, along with having a proper voice channel with separate transmit and receive audio links as well. There is a very common use of these phones in remote oil fields ( which also explains the coverage map, covering all major oil production areas) and in remote mining areas, where they are used for data links.Permanent ones ( or at least in a big heavy steel cabinet with batteries, the ruggedised computer and sensor arrays) also have an antenna that plugs in in place of the extensible circularly polarised antenna unit, providing the phone with a better antenna that is mounted on the roof of the container, where you can have a higher gain on the transmit antenna and a bigger receive antenna and LNB.Almost all older industrial computers still have RS232, and with the phone capable of emulating a proper Hayes modem, including having ring detect to wake up the remote site on command, you can do a lot over the 2400baud link of the phone. There are still remote sites using this to get basic voice comms, and text only email so they can stay in touch with a head office and send exploration data back fast, and more importantly securely, instead of having to drive to a town somewhere with basic phone or internet connectivity. some models were capable of having both voice and data connectivity at the same time.You pay for the service ( and boy do you pay per month for the basic service) and then you pay again for calls and data. One person I know was saying he had a similar phone, and after a call of about 20 minutes from somebody wanting him to come immediately, he replied that there was no way he could do it, seeing as he was at that time in Siberia, and 3 days travel from an airport. Then the question was " how much is this call costing" to which the answer was "$30 per minute", followed by a click. He was there with the phone, having rented it for the trip as there was otherwise no communications in that area.

author: nixfu
author_rank: Unknown
timestamp: March 05, 2015, 04:48:57 pm
content: Quote from: Fungus on March 05, 2015, 09:45:24 amInmarsat has the global coverage market, including maritime and aircraft usage. They use much higher satellites which I think are in geosync orbit. It provides pretty much entire planet coverage with three satellites.http://www.inmarsat.com/service/isatphone2/

author: SeanB
author_rank: Super Contributor
timestamp: March 05, 2015, 04:50:57 pm
content: Quote from: German_EE on March 05, 2015, 04:39:29 pmYou design the PCB to fit in the area to form a rectangle, then you go and have the dies made for the shields, and they get pressed out of tinned sheet steel. If you are only doing a few you can use premade shields, but there you are constrained by the shield. The roll your own allows you to have custom leadout slots in the shield for traces, and to have custom sizes and also have the option of having those shorting straps across the shield, or to have custom contacts to allow a press fit cooling clip for power devices.Off the shelf is cheap in low quantity, but the custom parts allow you to have smaller assemblies. The die costs though are pretty high, you are looking at $10k per set or so for each unit, comprising of a set of press plates, cutting dies and punches that form all the edges and holes in the unit, along with the clips to hold it together in a single set.

author: ornea
author_rank: Unknown
timestamp: March 05, 2015, 06:38:24 pm
content: Spot on Dave, those connectors have proven to be a massive fail especially with the heavy fisted users.

author: f4eru
author_rank: Super Contributor
timestamp: March 05, 2015, 07:46:25 pm
content: one of the chip you didn't find (first line was the datecode)http://pdf1.alldatasheet.com/datasheet-pdf/view/152301/QUALCOMM/Q5500.htmlQualcomm of course !

author: RupertGo
author_rank: Regular Contributor
timestamp: March 06, 2015, 01:23:11 am
content: The coverage map will be dictated by the downlinks to the earth stations. The Globalstar system uses (I think as mentioned in Mailbag) a very simple system where the satellites just act as bent-pipe analogue repeaters in space. LEO satellites have quite a restricted footprint, so you'll only get service if you and the ground station are within the footprint of whatever satellite you're using. (Hence the lack of coverage over the oceans.) You'll still get signals to and from the satellites if you're out of coverage range, but there'll be nobody to talk to.Higher satellites have a bigger footprint so need fewer ground stations to cover a wider area, and satellite-satellite relays are another option. All more expensive and complex, though.

author: ConKbot
author_rank: Super Contributor
timestamp: March 06, 2015, 05:16:38 am
content: Quote from: SeanB on March 05, 2015, 04:42:28 pmGood postOne minor thing is that on stuff in L and even S band, it will probably use an LNA (just an low noise amplifier) instead of an LNB (low noise block downconverter) as cable loss wouldnt be huge like it would be in the K/Ka/Ku range. I always wondered how they shrunk a LNB down to the tiny puck used for Sirius/XM antennas, then I learned it was 2.x GHz.The antenna in the teardown is really interesting, with the patterning inside and out, along with the different elements. And I like how the telescoping bit goes far enough to clear the users head to make for a good omni pattern.

author: Smokey
author_rank: Super Contributor
timestamp: March 06, 2015, 06:23:51 am
content: So Hugoneus (Shahriar Shahramian from the Signal Path)......Does it make you insane watching Dave talk about RF circuitry?

author: necessaryevil
author_rank: Regular Contributor
timestamp: March 06, 2015, 09:20:58 am
content: QuoteI guess the first one since the construction of those cans is quite simple. (I didn't say the design). It's also possible that they will do iterations.

author: Monittosan
author_rank: Regular Contributor
timestamp: March 06, 2015, 02:38:33 pm
content: Quote from: Smokey on March 06, 2015, 06:23:51 amLOLL!

author: SeanB
author_rank: Super Contributor
timestamp: March 06, 2015, 03:47:29 pm
content: I actually do have a worldspace radio in a cupboard. Wonder if i should do a destructive teardown on the remote antenna puck it has.

author: German_EE
author_rank: Super Contributor
timestamp: March 06, 2015, 03:58:42 pm
content: Ages ago I asked Shahriar to do a talk on Signal Path about RF Voodoo and all the various PCB based filters that can be seen. Maybe we will see it someday.

author: G7PSK
author_rank: Super Contributor
timestamp: March 06, 2015, 04:01:45 pm
content: Quote from: SeanB on March 05, 2015, 04:50:57 pmCustom made shielding cans can be made quite cheaply with tools such Amada turret punch press which use standard size punches to cut out various shapes.http://www.amada.co.uk/product/details/11/ae-nt-series

author: SeanB
author_rank: Super Contributor
timestamp: March 06, 2015, 07:29:25 pm
content: I think the punch press is going to be a little more than $10k though. Custom is cheap in lots up to 10 or so where you use a simple metal worker in a engineering shop to hand make them. Cheap at a half million, where you can amortise the cost of the machine and presses over a large number of units, and then you can sell the excess capacity as a 'standard' size. In between you buy standard or build in the cost of the machinery and dies, or have a die set made for an external press contractor.

author: Sasja
author_rank: Contributor
timestamp: March 06, 2015, 08:16:41 pm
content: question: what are those parts that look like crystal packages and have traces running underneath?

author: mxmarek
author_rank: Contributor
timestamp: March 06, 2015, 09:57:34 pm
content: Shouldn't You hold the antenna horizontally to get maximum signal gain up the sky ?

author: kotaKat
author_rank: Newbie
timestamp: March 07, 2015, 01:12:51 am
content: So, figured I'd step in. I've owned a GSP1600 and currently own an Iridium/Motorola 9505A and a Thrane&Thrane Explorer 300 BGAN terminal for Inmarsat. Both a couple good deals on eBayA few notes:- The orange tip? Like fake guns, they colored the tip of the erectile antenna orange to avoid people thinking you've got a gun.- If it's not activated, it'll register and unregister repeatedly with the Globalstar network. No test calls.- If you have CDMA (highly unlikely) you can register the cellular side. In the States for the longest time a Verizon MVNO did allow you to activate them on cellular, long past the E911 mandate. Of course, it was ONLY the cell side, so you still had two bills!- The network was quite shite for a long bit of time due to satellite failures and pesky end-of-lifecycle issues. They had service down to $35 US a month for "unlimited" service at one point, mind you - but you had to use a "call times" tool to see that you can only make a 5 minute phone call for maybe two windows in the hour.- The multipin connector on a lot of these terminals (not just Globalstar's) are full on docking stations for fixed stations. As an example, I could slot my Iridium into a dock that gives me RJ11 phoneline connectors, serial access, an external antenna, and lets me run it off mains power.- Native data rates are 9600 baud on Globalstar and 2400 baud on Iridium. Normally, TCP "acceleration" is provided to give you compressed data around 10-20k speed.BTW -- Globalstar will sell you their latest and greatest SatFi (satellite data/voice terminal for smartphones) for $1k US -- and all they give you is a Gumstix Overo, third-party WiFi module, and an off-the-shelf old stock Globalstar integrator's module - tied together with some dodgy rebranded OSS.

author: hikariuk
author_rank: Unknown
timestamp: March 07, 2015, 12:54:59 pm
content: Quote from: Fungus on March 05, 2015, 09:45:24 amMost ships use Inmarsat, ime.

author: DanielS
author_rank: Frequent Contributor
timestamp: March 07, 2015, 10:29:22 pm
content: Quote from: mxmarek on March 06, 2015, 09:57:34 pmThat depends on antenna polarization and in this case, I would guess it uses circular and gets the highest gain by pointing up.

author: Rory
author_rank: Frequent Contributor
timestamp: March 07, 2015, 11:23:45 pm
content: Quadrifilar helix.

author: EvilGeniusSkis
author_rank: Regular Contributor
timestamp: March 08, 2015, 12:52:44 am
content: Quote from: Tek_TDS220 on March 05, 2015, 04:08:03 pmwould the third girl have been named Keytone?

author: kotaKat
author_rank: Newbie
timestamp: March 08, 2015, 02:05:51 pm
content: Quote from: DanielS on March 07, 2015, 10:29:22 pmCorrect. That's also why they have the angled "detents" so that it stays pointing up when you hold it to your head.

author: mxmarek
author_rank: Contributor
timestamp: March 08, 2015, 11:32:38 pm
content: Quadrifilar helix is just pure black magic designed by demons

author: Stonent
author_rank: Super Contributor
timestamp: March 09, 2015, 01:13:20 am
content: Quote from: mxmarek on March 08, 2015, 11:32:38 pm

author: N2IXK
author_rank: Frequent Contributor
timestamp: March 09, 2015, 01:23:15 am
content: Well isn't that Speeeecial?

author: rollatorwieltje
author_rank: Unknown
timestamp: March 09, 2015, 08:15:36 pm
content: Ah, the 386EX. I have a board the size of a Raspberry Pi with one on it, dated around 2002. Power consumption of that board was about 300mA at around 33MHz. Quite a surprise to see one in a phone.

author: edy
author_rank: Super Contributor
timestamp: March 10, 2015, 12:51:16 pm
content: Dave, did I miss it or did we not review the mechanics of that "erecting" antenna? Was there a gear that drew out the antenna as it swiveled, or a pulley cable system? The mechanical side would have been interesting too although the electronics takes priority of course. Still, a bit of engineering marvel. Perhaps a quick 2 minute follow-up in your next video would help.