Extending Antenna

jschrauwen · 10-31-2006, 07:28 PM

I've got a Toshiba mini PCI WIFI card whose antenna leads are too short for my needs. They're a very thin gauge wire (white and black leads) that have a square 1.25" tabs on the ends at slightly staggered lengths. I'm not very familiar with this type of antenna and was wondering if I can just solder extra lengths of similar gauge wire to each lead? If so, do I still have to maintain the staggered length difference? I plan on routing those 2 square tabs to a spot on the upper front windshield on the passenger side. I estimate that I'd have to add approximately 4 feet of additional wire to each lead. Will adding that extra wire affect the antenna's sensitivity and capability?
Part of the bench testing process - Thanks in advance.

BarryWoods · 10-31-2006, 11:41 PM

Yes, adding extra wire will pretty much kill your signal. Those little bitty wires are coax, just like your cable tv, but much smaller. That gauge wire is also only used for really short runs, like 6 inches or less.

http://www.hyperlinktech.com/web/cab...UFL&pgType=ufl

jschrauwen · 11-01-2006, 02:37 PM

Quote: Originally Posted by BarryWoods

Yes, adding extra wire will pretty much kill your signal. Those little bitty wires are coax, just like your cable tv, but much smaller. That gauge wire is also only used for really short runs, like 6 inches or less.
http://www.hyperlinktech.com/web/cab...UFL&pgType=ufl

Barry, thanks for the info and link!!

The card I have is the Toshiba/Askey AR5BMB-43, PA3373U-1MPC. It looks similar to this;

The antenna that came with it is exactly like this one;

The antenna cable lengths are ~18"(white lead) and ~23"(black lead). How do I or can I extend these antenna cables so that the terminating square tabs will reach a spot in the upper inner passenger's side of the front windshield? Right now the antenna cables just sit loose outside of my Travla case. If extending is not an option what is the best way to orientate those antenna cables for best reception? The PC will be residing under the passenger seat.
Also, can you confirm that the antenna's card connectors are referred to as U.FL (Hirose™/iPax/Mini-PCI Compatible)?

jcdillin · 11-01-2006, 02:58 PM

Yes those are U.FL connections.

The way I did it on mine was convert the U.FL to SMA and then just used a standard antenna. That way you can run it anywhere you want. Those little peices of coax are not going to extend well and even if you do they will lose all the signal you gained by moving them up to the window.

edit: if you want to keep those little guys I would just stick them on each side of the case with a bit of double sided tape, I know inside the screens of the laptops they are just stuck to the back of the case on each side with some sticky tape.

jschrauwen · 11-01-2006, 03:18 PM

Quote: Originally Posted by jcdillin

Yes those are U.FL connections.
The way I did it on mine was convert the U.FL to SMA and then just used a standard antenna. That way you can run it anywhere you want. Those little peices of coax are not going to extend well and even if you do they will lose all the signal you gained by moving them up to the window.
edit: if you want to keep those little guys I would just stick them on each side of the case with a bit of double sided tape, I know inside the screens of the laptops they are just stuck to the back of the case on each side with some sticky tape.

Excellent, thanks JC, now I'm getting somewhere, or at the very least think I know where I should be headed. I found pics on that antenna routing to the back of a laptop case. Will using that 2 sided tape and attaching to the side of the Travla case present a realistic method for good signal strength? In my mind I think it would be very limiting, but then this is still very new to me.
I tried to find some how-to's or threads relating to antenna mods for the mini pci cards but I wasn't successfull. I'm not sure what is meant by "used a standard antenna"?

*Edit*
Is this the cable you're referring to?
U.FL (Hirose™/iPax/Mini-PCI Compatible) to SMA-Female Bulkhead, 1.13 Cable

jcdillin · 11-01-2006, 03:23 PM

Standard antenna, meaning like something off of a router, or the antennas that you find at compusa for enhancing your signal strength. I personally went with a magnent mount antenna t from ebay to stick on the outside of my car because my house is so far from where I park.

Yeah to be quite honest with you, I played around with those patch antennas and I wasnt really impressed with the signal strength. Granted I didnt mount them standing up just like on a laptop. So maybe someone else knows something I don't, thats why i went with the normal antenna.

BarryWoods · 11-01-2006, 08:58 PM

Quote: Originally Posted by jschrauwen

Excellent, thanks JC, now I'm getting somewhere, or at the very least think I know where I should be headed. I found pics on that antenna routing to the back of a laptop case. Will using that 2 sided tape and attaching to the side of the Travla case present a realistic method for good signal strength? In my mind I think it would be very limiting, but then this is still very new to me.
I tried to find some how-to's or threads relating to antenna mods for the mini pci cards but I wasn't successfull. I'm not sure what is meant by "used a standard antenna"?

*Edit*
Is this the cable you're referring to?
U.FL (Hirose™/iPax/Mini-PCI Compatible) to SMA-Female Bulkhead, 1.13 Cable

That's exactly what you want. The sma connector is what D-Link uses for it's access points, so any external antennas that say they will work with D-Link will work with that cable. Once you plug the cable into your network card stick it down with a little bit of tape. Those connectors are ungodly fragile.

jschrauwen · 11-01-2006, 10:02 PM

Quote: Originally Posted by BarryWoods

That's exactly what you want. The sma connector is what D-Link uses for it's access points, so any external antennas that say they will work with D-Link will work with that cable. Once you plug the cable into your network card stick it down with a little bit of tape. Those connectors are ungodly fragile.

Thanks Barry!!
That U.FL/SMA connector will replace 1 (Main) of the 2 antenna cables from the card, what do I do about the 2nd (Aux) cable?
Should I have 2 x U.FL/SMA cables going to the PC case body?
I take it that the antenna frequency I should be looking at is 2.4GHz??
Are these the right type of antennas I should be considering? http://www.hyperlinktech.com/web/mobile_antennas.php
So the type of cable I should be looking for to connect to the antenna is called "D-Link"?
Do these antennas take both the Main and Aux feeds from the PCI card? If so is there different type of antenna I should look for?

I know, lots of questions and unless this is already posted somewhere, my appologies and please direct me to the right thread because I just can't seem to find an all encompassing thread.

BarryWoods · 11-01-2006, 10:23 PM

You should be okay just using the main connector. Wifi is 2.4Ghz, that's what you're looking for. Those antennas should work for you. Whatever you do don't buy the "economy" one. They all look like they come with 10' cables, so you shouldn't need to worry about that. D-Link is a manufacturer of wireless equipment, that's why I sugested it, most local comp-usa's or best buy's have add on antennas for them. If you buy anything from hypertech, it doesn't really matter what connection you use, as long as everything has matching connectors.

jcdillin · 11-02-2006, 05:55 AM

if your going with an external antenna don't worry about connection the 2nd antenna. I have only one on mine and it works great.

jschrauwen · 11-02-2006, 12:25 PM

Quote: Originally Posted by jcdillin

if your going with an external antenna don't worry about connection the 2nd antenna. I have only one on mine and it works great.

I'd prefer not to have to drill any holes through the car body. I'm looking at perhaps the cable running up the A-Pillar(s) and locating some sort of an antenna near/by the sun visor / windshield but unobstructed by the roof. Would I increase my reception potential by having 2 interior antennas (on either side of windshield) or using a by-pole type antenna (if there is such a beast)?

BarryWoods · 11-02-2006, 01:01 PM

Quote: Originally Posted by jschrauwen

I'd prefer not to have to drill any holes through the car body. I'm looking at perhaps the cable running up the A-Pillar(s) and locating some sort of an antenna near/by the sun visor / windshield but unobstructed by the roof. Would I increase my reception potential by having 2 interior antennas (on either side of windshield) or using a by-pole type antenna (if there is such a beast)?

No, it would make it worse. One will do, where you want to put it should work as well. I'm saying should, because the radiating pattern of the antenna will be effected by the pillar, and it's not going to be oriented correctly. Antenna's should be polarized the same for the best connection. Most home access points use vertical polarization. This means that the antenna is straight up and down. Yours will have some tilt to it because of the windshield. This will cut down on the signal, but if you are in your driveway you shouldn't have problems.

jschrauwen · 11-02-2006, 01:33 PM

Quote: Originally Posted by BarryWoods

No, it would make it worse. One will do, where you want to put it should work as well. I'm saying should, because the radiating pattern of the antenna will be effected by the pillar, and it's not going to be oriented correctly. Antenna's should be polarized the same for the best connection. Most home access points use vertical polarization. This means that the antenna is straight up and down. Yours will have some tilt to it because of the windshield. This will cut down on the signal, but if you are in your driveway you shouldn't have problems.

Thank you Barry! That's good to know and also a little less expensive from my previous thinking. I can understand the polarization part a bit from my radar theory many moons ago (horizontal, vertical, circular, polarized beam patterns and the like). Then it's probably best to route the cable (length providing) under the headliner to mid windshield where it will emerge and be attached to an appropriate antenna. When parked, I can let the antenna hang downward for best reception. There's an opportunity to be "connected" while on the fly in parts of Ontario. Toronto is the first to provide an open source for a majority of the downtown area. This means that one can be connected to a free open source which I found quite interesting and was only announced a few months ago. I digress, back to the situation at hand.
I don't live near any major centers at present so shopping for the antenna and cabling will be a bit difficult. Ebay may be an option but I'll have to know exactly what I'm "shopping" for. I'd like to do this right the first time, so I guess what I'm really asking is, if cost wasn't a big issue and this were your project and you were looking for quality components with exceptional performance, what parts would you recommend I search/look for?

BarryWoods · 11-02-2006, 07:03 PM

No one up here carries this kind of wifi stuff. I usually get all my stuff from www.fab-corp.com . They're based out of Florida. You'll need the pigtail to go from u-fl to whatever, then a jumper with whatever the pigtail has to whatever the antenna you get has. They can custom build cables as well, so if you know how long it is from where your carputer will be to the headliner they can make one that long. Just take into account that most coax cable has a minimum bend radius. No sharp 90's! Most of the cable I deal with is LMR-400, it's about a half inch thick with a bend radius of about 8 inches. For your setup I wouldn't go with anything smaller than LMR-195. I'm not too sure what the bend radius is for that though. Shoot them an e-mail, tell them what you are wanting to do, they'll know the best parts to use waaaay better than I do.

jschrauwen · 05-19-2007, 07:57 PM

Since my laptop is toast, I'm going to be bringing my CarPC with me to Afghanistan in July. (it 's never been installed in the car yet anyway)
Since there apparently is going to be wireless internet availability there I'd like to get going on my antenna purchase and testing before I go. Although this set-up will be used in my room in camp I''ll be looking to continue using this antenna afterwards when the PC is installed in my Z.
I'm considering this antenna;
http://www.hyperlinktech.com/web/hg2407mgu.php

It only come in N-Female connector or RP-SMA connector. I'm assuming I should be going for the latter - RP-SMA because of the U.FL pigtail I wish to use.
I like to go with this U.FL pigtail cable to my card;

I need to know which U.FL pigtail to select. Do I go with the SMA-Female Bulkhead jack;

or the RP-SMA Bulkhead jack;

I'm hoping to order these items up within the next few days so that I'll have time to install and test before packing everything up for my deployment for 6 months. I'd prefer to order everything from the same place for shipping and conveniance sake. My appologies if this appears to be a dumb question. cheers,
John