External Antenna Socket - WARNING

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Sliovic

Member
Apr 11, 2014
18
0
Ok guys i almost had a heart attack!!!! i though my Galaxy S3 was gone since i rooted it the first night i bought it. (bye bye warranty).
anyway.. like many guys here i tried to boost my phone signal by plunging a wire into that little stupid hole because of the bad reception i get in my room. and as you can see i'm stuck just like many of you...
after reading some posts here a realized that it's only a matter of connecting the two connectors inside the socket to solve the problem, therefor i will just leave the wire there.


EDIT: This is bad !! even with the wire in, it doesn't seem to work right especially when i close the phone cover... i get the 'emergency calls only' thing... and when i get the signal it's too low and even worst than before.... i mean why ??? if only what i need is to connect the two connectors inside the socket ???
 
Last edited:

Kris_BL

New member
Dec 25, 2014
1
0
*** Thank You x 1'000'000 ***

the same thing happened to me after trying to make my own cheap wire aerial...
i have GOOGLE'd many times to try find a way to get it back to working-order because having a piece of wire hanging from my phone's bum was not nice & i use a SAMSUNG 5301 (Pocket Plus) & the connector is actually underneath the battery, so it caused the battery to disconnect sometimes....
This post is the only one i have found so far with Nicely Detailed FACTS & it's Proven to be Truly Useful ~
Thank You for Making the Effort & Doing the Research, it is Extremely Helpful & Very Much Appreciated !!!

>>> I Salute You ! ! !
:highfive:
 

hellcore

Member
Oct 9, 2012
18
5
Castelar
I like this post. Really interesting, unfortunately I've touched this socket and my internal antenna it has disconnected. Do you think I could fix it if I buy a new socket and soldering it?

Hi dude, read the entire post. You can replace the antenna socket but before doing that you may want to try filling the hole with tin. Just melt tin with a soldering tool and throw it you'll get something like this.

Tin-2.jpg


Then cut it in very tiny pieces, you get something like aluminium paper, use a needle to push:

1192416582403jpg.jpg


And this gave me an idea, alumnium paper may work too...
 

alwaysfresh

Member
Jul 2, 2013
23
1
Timisoara
After bypassing the antenna socket, my phone lost its IMEI and Baseband got unknown. Did any of you had this problem?
I really am desperate to solve this. Tried almost everything on the internet and nothing solved the problem.
Any help?
 

Dr.Hammer

Member
Apr 2, 2012
13
27
Copenhagen
Ok guys i almost had a heart attack!!!! i though my Galaxy S3 was gone since i rooted it the first night i bought it. (bye bye warranty).
anyway.. like many guys here i tried to boost my phone signal by plunging a wire into that little stupid hole because of the bad reception i get in my room. and as you can see i'm stuck just like many of you...
after reading some posts here a realized that it's only a matter of connecting the two connectors inside the socket to solve the problem, therefor i will just leave the wire there.


EDIT: This is bad !! even with the wire in, it doesn't seem to work right especially when i close the phone cover... i get the 'emergency calls only' thing... and when i get the signal it's too low and even worst than before.... i mean why ??? if only what i need is to connect the two connectors inside the socket ???

When you leave the wire in you switch of the internal antenna. So the only antenna used is you new wire :). Don´t do that:)
 

evilv

Member
Dec 16, 2006
47
2
Hi Guys,

Old thread but there are probably still people using the Galaxy S2 and encountering this problem. I came to it after replacing a bad USB / Charging port unit with a cheap after market part from ebay. I have done this twice on my old and much abused S2. The second time I got a fake or not correct version USB port. The USB and charging port bit worked fine, but the RF signal transits the port to get to the internal GSM 3g antenna in the base of the phone. It is VERY COMMON for these ebay parts to not connect properly to the phone internal antenna. Loads of people have this problem if you google the issue of low signal after replacing the USB / charging port. This is because there is no connection through some of these ebay ports to the antenna, or they get the wrong part. After fitting the board I had a VERY weak signal about -113dbmW when my wife's S2 was showing about -72dbmW at the same time in the same position. Hopeless.

Anyway - I saw that neat little testing RF port and made a small antenna of the correct measured length and got at least a 10db signal gain by doing that (in comparison to my defunct internal antenna). A couple of points though:

You MUST make sure that the wire you use in the centre of the hole is insulated from the shell of the little RF port.

You MUST cut the wire to the correct length for the RF signal frequency you are using. Antennas need to be resonant at the frequency in use not some random length.

My GSM service is at 1800MHZ and my 3g service is at 2100 MHZ. Since I only use the phone for GSM calls not data, I cut the length of my antenna for 1800MHZ which means I need 36mm OUT OF THE HOLE, so I made my wire 39mm total which includes the bit that goes into the connector. The wire is at most 0.3mm diameter, 5 amp fuse wire.

I had my phone completely open and I removed the tiny white coaxial cable from the USB board and the RF board and put it aside in a safe place in case I want to restore normal operation later.

I then covered the wire except for the lower 2.5mm by sandwiching it in insulating tape and trimmed off the surplus width so I had a strip of plastic covered wire with 36mm covered and about 2.5mm bare. It is important to have a narrow strip because I need to lose that wire into the groove that used to accommodate the white coax wire to the internal antenna (which is now useless because of my bad USB/charging port).

I also used a jewellers loup so I could see to carefully cover the ground parts of the shell of the rf socket with scraps of insulating tape. When I bend over the wire to run down the little channel for the coax cable, there is a risk that it might short circuit the tiny RF port. I saw one photo above where someone had inserted bare wire twisted and that looked like it probably short circuited the RF port.

Now, having inserted the tiny wire antenna, check the signal. I had two galaxy s2 phones side by side on the same carrier and I got more or less the signal strength on both of them at the same time. When satisfied that the signal is OK, carefully bend the little wire antenna over and tuck it into the channel that used to hold the little white RF cable that you already disconnected. Then replace the back shell of the phone and the screws which hold it on, being careful about the placement of the power and volume buttons which can sometimes fall out as you are putting the phone back together. I found it best to have the back facing upwards on the desk and place the main body of the phone onto it, face up. Insert the top of the screen first and checking the volume and power buttons remain in position, snap it together.

WARNING:

If attempting for some reason to replace the internal antenna either because you have a bad usb/charger board like me, or because you broke the little RF socket by meddling. YOU MUST work out the correct length of antenna for your carrier and service. I have gsm 1800MHZ from EE in the UK. YOU though may have gsm 900 mhz, in which case you will need a longer antenna. you can work out the length of a quarter wave whip antenna (which is what we have here) by using the following formula:

143/F all divided by 2 , where F is the frequency of the carrier's service to you. his gives an answer in meters.

143/f (IN MHZ) Gives the length of a half wave at the frequency. Divide that by 2. This gives the 1/4 wave length in meters. Multiply by 100 to get it in centimetres and that is the length of the wire OUTSIDE the hole.

For the record GSM 900 needs 79.4mm antenna length which you can probably lose down that channel for the white RF cable WHICH MUST BE REMOVED. You can't have a radiating antenna right alongside another wire or significant metal part without ruining performance.

This solution for my OLD phone probably does not provide an ideal impedance match and I would not do it for a good , new phone, but to save my almost five year old battered Galaxy S2 from the trash bin, it works and gives almost original performance on the service it is designed for (1800MHZ. It works on 2100MHZ data too but probably not as well.

It ain't perfect, but it works. If you want to go for a Rolls-Royce job, you could experiment with antenna length using the signal strength read out in the status menu by making the intitial wire a bit too long and snipping back a couple of mm at a time to see where you get the strongest performance. bare in mind that the signal strength from the cell tower goes up and down depending on factors we have no control over so only do this if you have another phone to compare side by side.

Good luck

EvilV
 

richardb2550

New member
Feb 19, 2016
2
0
Guys: :silly:

I correct this post as I trusted a previous one regarding the right connector (I personally ordered 2 cables and realized I had ordered the wrong one). Luckily the wrong connector just will not fit

The correct connector is a Hirose but model MS-162 and not the MS-147. :silly:

Messing with tiny connectors with just a wire in such a delicate piece of electronic equipment is to say the least dangerous......

(some background I am an electronic engineer and did my fair share of electronics fiddling as a younger man..)

The connector most of you refer is actually a coaxial switch manufactured by Hirose Electronics, as correctly stated an MS-147 SO SORRY incorrect previous model, the correct connector is an MS-162 (smaller even than the MS-147).

. . .

Hope this clarifies a bit better

The MS-147 is 3.4 mm diameter (see html.alldatasheet.com/html-pdf/81360/HIROSE/MS-147/735/4/MS-147.html), while the MS-162 is 2.8 mm diameter (see farnell.com/datasheets/58835.pdf) (that's the external diameter of the socket on the board, the internal diameter of the plug that will fit it).
 

chrisyd508

New member
Mar 28, 2016
1
0
antenna fix

I broke the antenna on my samsung phone by sticking some thing n it I fixed it by pulling the old one of with a knife and fone a old mother board with antenna on it and just glued it down now my signal is fully working again if you have a problem with ur antenna just find and old phone and replace it u dont need to solder it down as long as the connecters are touching the antenna u should get signal it worked okay for me
 

nickyip123

Senior Member
Apr 25, 2014
152
25
Nokia 8.1
Realme X
Hi dude, read the entire post. You can replace the antenna socket but before doing that you may want to try filling the hole with tin. Just melt tin with a soldering tool and throw it you'll get something like this.

Tin-2.jpg


Then cut it in very tiny pieces, you get something like aluminium paper, use a needle to push:

1192416582403jpg.jpg


And this gave me an idea, alumnium paper may work too...
I'm quite sure this won't work...
 

waliuxd

Senior Member
Oct 16, 2015
55
14
Lima
Hey guys.
This is my first post on XDA.
I was so "lucky" to but a cheap used S2, with the promise that it worked 100%.
Unfortunately this wasn’t the case. When I got home I quickly realized that the signal was extremely poor, with the same sim card and carrier as a have used on my old HD2. Instead of finding the ***** that sold me the phone and hitting here with a pipe, I started updating the phone and searching the web for answers.
I found you guys in here and started investigating if I was falling victim to the same external antenna connector error.
Fortunately I am an electronic engineer, and have access to the right equipment for the job.
I first notates that the external connector look like it had been damaged. Maybe someone had used a wrong connector :(. See first photo.

I found the data sheet for a similar connector (MS-147) and it did have a internal switch that disconnects the onboard antenna when a external is connected.
Data sheet, page 4:
I am not allowed to post a link to the datasheet but do a google search for “hirose MS-147 pdf”

I verified that the internal switch where broken by some simple connectivity measurement and I also tried make a small antenna with some thin wire place in the connector. The small wire gave me a couple of bars in signal strength.
So I went for it and soldered the connector out and replaced it by a small wire that connects the transmitter/receiver to the internal antenna.


Hope this helps shed some light on the issue and one way to fix it.
I would only recommend this solution if you have a thin soldering iron and some experience using it. I used a microscope as well, but this is a luxury I used because I could:).

I think that this connector can be use as an external antenna connector, but only with extreme care and most definitely only with cable using a 100% matching male connector.

I so in another forum someone recommend a inductive cradle that can be hook up to a external antenna with a big improvement.
Again I can not poste direct link since I am a noob…..
But do a google search for this part no: CK589-AMGC

what kind of wire did u used for soldering? (that green cable) magnet wire?
 

orangpelupa

Senior Member
May 29, 2012
471
117
Thanks a ton everyone! Fixed my xiaomi redmi note 5 no signal by stabbing the port multiple times while watching the SIGNAL info accessible from *#*#info#*#*
 

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  • 27
    I have been attempting to use the antenna socket located under the battery cover on my S2. Sometimes I go to a very remote location for a week where I can only get reception via a amplified Yagi pointing at the nearest transmitter (Orange only as well, no other networks for miles.) I currently use a P1i for this as being dated it has an antenna socket.

    I wanted to do the same with the S2. I was very excited to spot the antenna socket under the battery cover. Much research online doesn't really give much information about it; neither did a phone call to Samsung (who were unhelpful.) Some online shops in Australia sell a constructed link for it but nobody here in the UK does, as far as I can tell. So I was looking at creating my own pigtail lead.

    Having difficulty finding what precisely the socket is, (it isn't an MCCX I can guarantee, others report it isn't an MCX) I took a thin wire and pushed it into the centre to see if I could bodge a connection together.

    Big mistake! The external antenna works - but now the internal connector doesn't. Whenever an external antenna is connected it disconnects the internal one. It turns out that if you use the wrong side wire, it appears to force apart two contacts within the socket (best I can tell with my loupe) and the internal antenna never works again.

    I suspect the solution for Galaxy S which sometimes had a spontaneous similar issue - removing the antenna socket and shorting the contacts - would work, but it's not at all simple to do especially given the infrastructure on the other side of the PCB.

    People think that this socket is only intended as a test point for use by Samsung before shipping the phone. I would strongly suggest NOT MESSING WITH IT or using it - and if you do, to buy (import if necessary) the specially made cable. Otherwise you may suffer my fate and have no internal antenna connection any more.

    Beware...
    26
    Removing the broken external antenna connector and only using the internal

    Hey guys.
    This is my first post on XDA.
    I was so "lucky" to but a cheap used S2, with the promise that it worked 100%.
    Unfortunately this wasn’t the case. When I got home I quickly realized that the signal was extremely poor, with the same sim card and carrier as a have used on my old HD2. Instead of finding the ***** that sold me the phone and hitting here with a pipe, I started updating the phone and searching the web for answers.
    I found you guys in here and started investigating if I was falling victim to the same external antenna connector error.
    Fortunately I am an electronic engineer, and have access to the right equipment for the job.
    I first notates that the external connector look like it had been damaged. Maybe someone had used a wrong connector :-(. See first photo.

    I found the data sheet for a similar connector (MS-147) and it did have a internal switch that disconnects the onboard antenna when a external is connected.
    Data sheet, page 4:
    I am not allowed to post a link to the datasheet but do a google search for “hirose MS-147 pdf”

    I verified that the internal switch where broken by some simple connectivity measurement and I also tried make a small antenna with some thin wire place in the connector. The small wire gave me a couple of bars in signal strength.
    So I went for it and soldered the connector out and replaced it by a small wire that connects the transmitter/receiver to the internal antenna.


    Hope this helps shed some light on the issue and one way to fix it.
    I would only recommend this solution if you have a thin soldering iron and some experience using it. I used a microscope as well, but this is a luxury I used because I could:).

    I think that this connector can be use as an external antenna connector, but only with extreme care and most definitely only with cable using a 100% matching male connector.

    I so in another forum someone recommend a inductive cradle that can be hook up to a external antenna with a big improvement.
    Again I can not poste direct link since I am a noob…..
    But do a google search for this part no: CK589-AMGC
    9
    Folks,

    I find the schematic of that connector, helps me to resolve my problem, I'm a junior here in XDA Forum, so I only can atthach files.. here is.

    I made a simple little schematics to show how I understand the problem and how I solved (for me work).... sorry for poor quality of art, I'm a noob in photoshop.

    I hope that elucidade more, afterall :"A picture speaks a thousand words"..

    Regards,
    8
    i9100 GSM loss strength problem

    Folks,

    I think I solved that problem with a easy procedure ! Work for my, maybe work for others....

    I'm noob here yet...So I can't put link,I will try to explain only with words (my english is so-so...sorry for that)

    As other in this thread, I made the same mistake: connected wrong RF antena cable in my Samsung Galaxy S2 i9100 (VIVO BRAZIL with OFICIAL Jelly Bean 4.1.2....I try to install other rooms, to verify is a software problem, but I realised was a hardware problem) and damage the little RF conector ... so, after that my GSM signal is very poor in most areas I use...except in my work, but I believe is because is a build with 9 floor ....so I think this don't count !

    For my lucky, my wife have too a i9100 and in attempt to understand the problem, I disassembly entire these two i9100 e exchange almost parts between the phones.... conclusion: Really is that conector that Dr. Hammer mentioned, unfortunately is virtually impossible to change that if you don't have the properly equipment and experience with micro-soldering...in my case I haven't.

    But, like a average brazilian guy, I don't have much money to spend in a new smartphone (I think this is globally for most folks here.. kkkkkk)....I decide to search more deeper to solve this problem.

    Even without experience and equipment, I decide to take this conector, I find that correct name, is RF Switch Connector MHC-705.

    So, obviously I wouldn't try first in my i9100, afterall... I consider a noob in electronic area.... and even the GSM signal is dead, the device still works perfectly for other purposes (surfing in web, games....) so I get a old LG KP130, who has a similar conector.

    The problem is that soldering is in the PCB (motherboard) surface (made by machines or other process tha don't envolved human hands)...so is very trick to take out, but I was able to take out that conector, the problem is it fells apart when I take out from PCB (useless to my i9100) .... moreover, when I tryed soldering a little tiny cable (to emulate what I will do in my i9100), the heat of soldering iron (a normal one, 40w) burns some parts of PCB (even I care to don't touch in PCB surface)...result: the internal antena of Lg KP130 don't work anymore.

    So I realise isn't possible to do the same in my i9100....After that, I accepted I was a owner of a "Samsung's Ipod" .....

    But, meanwhile I clean the mess,I had idea: Ok, some folks inserted little cables in that conector and work.... I if I could put some solder in that little hole to fill the connecor, will be resolve ?

    I got some solder (after melted by soldering iron.... some little fillets of solder has drop in the table during ther process .. I really don't know if the proprerties of melted solder is diferent.. I used solder after has melted by a iron and was cold) and a needle and begin to put in little hole of the connector of my i9100... I pressure a little the needle so put more as I can.... and voilá !! the signal strength UP to 100%.... and after 2 week still that way!!

    I travelled to other areas and signal still the same when I don't have this problem.....so I belive I fix that.

    The advantage I see in this method compare to the others (Dr.Hammer, the brazilian khazmodan or Argentine hellcore):

    - Easily to do: if you have a good eye and hand
    - Very cheap: some melted solder and a needle
    - Very quickly.: I took about 5 minutos to do all that (subtract the process of KP130)
    - No need dismount: only open the back of you phone ant take out the battery for prevention
    - Less invasive: Don't change the stetic of device....because ins almost impossible to see the solder in the conector.

    Cons:

    - You will never could (never is strong in that area, but will very hard to do taht) connect other RF cable in the MHC-705 RF Switch connector again (I think is a good one...kkkkk)
    - You need buy a Soldering iron and solder (Here in Brazil is relative cheaper...some like U$ 10)

    I can tell too that my friend connected the same wrong cable in her i9300 and get same problem....but for her lucky, the phone still in warranty and the reseller would change the motherboard....maybe he will get in 04/01/13 her phone

    I hope that could help others to solve similar problems....

    Thanks a lot to all folks in this thread, specially to Dr. Hammer and my compatriot Khazmodan (Khazmodan: here, in Porto Alegre, a local shop charge R$ 150,00 .. about $ 75,00 to do same that Dr. Hammer suggest, but they don't garantee will work... in fact they saw that is possible to bricket my phone too....without refound).

    Best regards.
    5
    For the curious full disclosure

    I'm another victim of own curiosity :'(

    My internal antenna is broken after playing with external connector. It worked though for couple of plug ins and outs. Now it's dead, what a shame.

    I'm forced to use a tiny cable in external antenna connector. To be honest the phone now behaves very strangely.
    Since I live in poor reception area I have exactly one spot on my table where I get full bars (using loudspeaker to make phone calls); other places give me minimum reception and cuts during a call.
    And now the fun part. The cable I use is 6cm long, aluminum made, 0,5mm thick or less. Since my provider allows roaming (some sort of agreement between cell networks in my country) and I have automatic network set, even though my home network should have priority, in the very same spot I had full reception before (on internal antenna) of my home carrier, right now I have none but other roaming carrier has full bars.

    I know that external cable length corresponds to MHz, i.e. 1800MHz needs 16cm long cable (at least that's what I have found).
    How many MHz is 6cm antenna then? This way I can figure out on which freq my phone operates.

    Thanks.

    Guys: :silly:

    I correct this post as I trusted a previous one regarding the right connector (I personally ordered 2 cables and realized I had ordered the wrong one). Luckily the wrong connector just will not fit

    The correct connector is a Hirose but model MS-162 and not the MS-147. :silly:

    Messing with tiny connectors with just a wire in such a delicate piece of electronic equipment is to say the least dangerous......

    (some background I am an electronic engineer and did my fair share of electronics fiddling as a younger man..)

    The connector most of you refer is actually a coaxial switch manufactured by Hirose Electronics, as correctly stated an MS-147 SO SORRY incorrect previous model, the correct connector is an MS-162 (smaller even than the MS-147). The purpose as stated in its data sheet is the following QUOTE

    "The ultra-small MS-147 coaxial switch was developed for the portable terminal interface and for inspection of microwave boards (substrates) (DC – 6GHz) used at high frequencies. Designed to be used as the interface antenna connection for portable terminal devices as well as circuit testing on microwave boards (DC to 10GHz) the coaxial switch offers high performace, low loss, extremely high durability and reliability, in a small and lightweight package.

    To respond to the development of portable terminal technologies and popularization of high frequency applications – up to 6GHz – this switch features low loss, low profile, and light weight.

    The switch circuit is designed so that the NC terminal is connected to the C terminal without a plug mated. Mating with a plug opens this
    connection.


    "

    END QUOTE ;)

    Reading where it states to be used for high frecuencies another acronym comes to mind KISS (Keep It Short Stupid), every high frequency design or fiddling involves short cabling, otherwise trouble comes (wavelength and distance involved), so it is not recomended to use just a wire for these purposes.

    On other hand the connector is guaranteed by Hirose as able to withstand 12.000 mechanical operations !!!!!! more than enough, PROVIDED YOU USE THE RIGHT MATING CONNECTOR EITHER

    MS-147MS-162-C(LP)-1 THE ONE USED BY THE AUSTRALIAN PROVIDER MENTIONED IN PAGE 2 WITH A CABLE AND FME CONNECTOR

    OR MS-147MS-162-HRMJ-1 DIRECTLY MATING TO AN SMA FEMALE CONNECTOR

    I would not suggest for the faint of heart or unexperienced to try to do your own cable or actually CHANGE the connector once it has been destroyed internally by inserting wires, but it can certainly be done with the right skillset, magnifying glass and special thin point solder iron.

    Full details and specs can be found in the data sheet available at MOUSER ELECTRONICS, as far as I know the most complete stock in electronics components available on the web (no connection at all..) search in Mouser for Hirose MS-147MS-162

    Complete data sheet in e35801505e35802083-32633.pdf at hirose japan (sorry can not paste the link)

    Conclusion in order of possiblities:

    1.- If you already destroyed the switch connector with a wire or wrong connector you can actually buy the part at Mouser and have it replaced, strongly suggest a cell repair shop as soldering tiny parts skills is definitely a prequisite. With this solution your phone is stock again.

    2.- If you do not want to go thru that trouble I guess the pin and push preheated solder in the hole will create a permanent connection for the internal antenna to work correctly (no wire since KISS).

    3.- If you have not yet destroyed the switch either get the cable from the Aussie vendor or wpsantennas (model WA-1071) in the US, and use whatever antenna you feel like connecting the FME to a yagi, omnidirectional or whatever one you have (eventually a car antenna if equipped with FME conector)

    4.- If able, go buy one of the mating connectors from Mouser, use the right 50 Ohm cable and connect to whatever antenna you have, I personally will do a cable for my BMW equipped with its own antenna connector.

    Hope this clarifies a bit better

    p.s. FME and SMA are normal antenna connectors, will find several vendors offering antennas with either one