Treo Antenna Hack

Place to discuss electrical design, tweaks, etc
nonobeez
Techie
Posts:58
Joined:Mon Sep 05, 2005 2:12 am

Post by nonobeez » Wed Sep 07, 2005 2:39 am

ok... makes sense. Here is another question, can verizon phones roam on Sprint networks and vise-versa? I am guessing they can. Then that would only mean technically they only have a different ROM and antenna (and colors) and that is it... am i correct?

If the antennas are indeed different, then maybe I should get a Sprint compatible antenna to use on my GSM phone since I strictlly use the 1900 MHz network, even internationally. What do you think?

User avatar
spymongoose
PDAPhone Hacker Team
Posts:433
Joined:Wed Jan 05, 2005 10:37 pm
Location:Las Vegas
Contact:

Post by spymongoose » Wed Sep 07, 2005 6:46 am

Yes, roaming by definition is using other cell towers to complete a call.

Your idea would be great if you could select a frequency band on your phone. Some GSM phones allow you to do exactly that, let the user select the freqs that he/she thinks is best. This feature has not been hacked out of the treo 650, but not for lack of trying.

But hey then if you know that you're limited to the 1900 range all the time, then go for it. Build yourself a dipole antenna! Each pole for 1900/sprint will be 1.47 inches long. Buy a cable, solder the center conductor to one pole, the shield to the other, just like I did. put the 2 poles end to end and mount them somehow. Let me know if it works!

Heres a diagram, just ignore the numbers as they are for a different freq:
Image

Designing a multi-band antenna is not easy. You start with a lenth for the longest wave (lowest MHz) and add capacitors of an exact value to meet the reactance, in parallel, to make an electrically shorter parallel antenna. You do this for each band... (ie 850/1800/1900)

My GSM design, although only on paper, used a 1800 MHz antenna, with a capacitor and an inductor in parrallel to give me 1900 and 850.
Talkabout T900 --> Handspring Visorphone --> Kyocera 7135 --> Treo 600 --> Apache PPC 6700 -->Nokia 770
http://www.shadowmite.com http://www.ppc6700users.com

nova9
Newbie
Posts:1
Joined:Sat Sep 10, 2005 11:12 pm

Replacement

Post by nova9 » Sat Sep 10, 2005 11:15 pm

Hi, I was wondering is it possible to design a new Treo 650 Antenna that replaces the one inside the Treo 650, with nothing dangling or external attachments.

nonobeez
Techie
Posts:58
Joined:Mon Sep 05, 2005 2:12 am

Post by nonobeez » Sun Sep 11, 2005 12:29 am

Probably, but I think the objective here is to make a better antenna than what is possible with an internal one.

User avatar
spymongoose
PDAPhone Hacker Team
Posts:433
Joined:Wed Jan 05, 2005 10:37 pm
Location:Las Vegas
Contact:

Post by spymongoose » Sun Sep 11, 2005 2:02 am

Image
Thats a treo 600 antenna, the 650 antenna is not much different. That little tab touches a contact on the edgeof the modem board and then the antenna is tightly coiled up in the nub. Not many folks realize this, they think the antenna runs the lenth of the treo. In fact there is no room for anything inside the treo, whitch unfortunatly makes me strap an antenna onto the outside of the treo. There is also a handy little antenna connector on the back of the treo.

Now there are a few types of antennas, and they all work although some better than others. I choose a dipole antenna, because of its hi gain omni pattern with ideal ground to ground communication ablilties. The downside is the amount of space it uses, probably the reason why it isnt used widely. The reason why the treo uses a coil antenna is because of the size issue. They made it as small as they could get it at the cost of performance. So to improve performance, Im using more space.

How much more space is neccesary is dependant on the operating freq. The picture of my antenna is a worst case senario, it uses a dipole antenna at 800 mhz. It physically occupies a full 1/2 wavelenth, equal to almost 7 inches. The same half wavelenth on sprint (1900mhz) is only 3". A triband GSM antenna would use 850 mhz, 1800 mhz, and 1900mhz, whitch is why I havent built any GSM antennas yet.
Talkabout T900 --> Handspring Visorphone --> Kyocera 7135 --> Treo 600 --> Apache PPC 6700 -->Nokia 770
http://www.shadowmite.com http://www.ppc6700users.com

User avatar
spymongoose
PDAPhone Hacker Team
Posts:433
Joined:Wed Jan 05, 2005 10:37 pm
Location:Las Vegas
Contact:

Post by spymongoose » Wed Sep 14, 2005 3:12 am

Talkabout T900 --> Handspring Visorphone --> Kyocera 7135 --> Treo 600 --> Apache PPC 6700 -->Nokia 770
http://www.shadowmite.com http://www.ppc6700users.com

bww143
Minion
Posts:20
Joined:Thu Aug 25, 2005 6:44 am

antenna adaptor?

Post by bww143 » Fri Sep 16, 2005 5:38 pm

Would a treo 600 external antenna adaptor work for this project? Thanks

User avatar
spymongoose
PDAPhone Hacker Team
Posts:433
Joined:Wed Jan 05, 2005 10:37 pm
Location:Las Vegas
Contact:

Post by spymongoose » Fri Sep 16, 2005 6:01 pm

It sure will! My prototype was on a 600. Both the 600 and the 650 have identical antenna (FME) ports on the back.
Talkabout T900 --> Handspring Visorphone --> Kyocera 7135 --> Treo 600 --> Apache PPC 6700 -->Nokia 770
http://www.shadowmite.com http://www.ppc6700users.com

bww143
Minion
Posts:20
Joined:Thu Aug 25, 2005 6:44 am

two more questions

Post by bww143 » Fri Sep 16, 2005 6:40 pm

thank you. Two more questions.

1.Can the choc block be found at Radio Shack or similar place.

2. I am not sure about the shield... Do you mean the balck outer coating that is usually found on the outside of the coax cable? Is it the "outside insulation" in your picture?

User avatar
spymongoose
PDAPhone Hacker Team
Posts:433
Joined:Wed Jan 05, 2005 10:37 pm
Location:Las Vegas
Contact:

Post by spymongoose » Sat Sep 17, 2005 9:17 am

The shield is the wire wrapped around the center core. It is called the copper mesh in this picture, as you can see the outside insulation covers it. Leave the inside insulation on the center conductor as long as you can, the center conductor is quite fragile.
Image
\
Yes, the choc bolck can be found at radioshack, I think they are called terminal boards. They are an easy way of connecting the wires to the antenna without solder. They are simple screw connectors. I personally soldered mine, but using a "choc block" is just as good of a solution.

please refer to the diagrams here, the measurements are correct there:
http://shadowmite.com/wiki/index.php/Bu ... MA_Antenna
Please let me know how it turns out, and feel free to ask for help.
Talkabout T900 --> Handspring Visorphone --> Kyocera 7135 --> Treo 600 --> Apache PPC 6700 -->Nokia 770
http://www.shadowmite.com http://www.ppc6700users.com

User avatar
spymongoose
PDAPhone Hacker Team
Posts:433
Joined:Wed Jan 05, 2005 10:37 pm
Location:Las Vegas
Contact:

Post by spymongoose » Tue Sep 20, 2005 4:12 am

With the 6700 getting into my hands soon, I have redesigned the antenna to fit it. How My first 6700 antenna will be built will be small and simple, using the connector itself to mount it to the phone. Because of this it will work equally well on any sprint CDMA phone with an FME connector. Thats right, the Treo 600, the treo 650, the PPC 6700, the PPC 660x, and the new treo (if it ever gets released will all be able to use this. I originally rejected this design because it wouldnt work very well for verizon folks. This incarnation may be easier to build and use, so Im going to have detailed and illustrated instructions as to how to build one.

Because it simply snaps on and off it may be better for more "casual" users, allowing you to attach a cool hi performance antenna to give you some more range when you need it... and to be tucked away when you dont need it.

Its just a step towards being a marketable commodity. You guys can build your own... Just keep checking http://shadowmite.com/wiki/index.php/Bu ... MA_Antenna With a total estimated project cost of about $10 and a sleek tech-savvy mongoose answering your emails it certainly worth a shot.
Talkabout T900 --> Handspring Visorphone --> Kyocera 7135 --> Treo 600 --> Apache PPC 6700 -->Nokia 770
http://www.shadowmite.com http://www.ppc6700users.com

Westronics
Newbie
Posts:2
Joined:Mon Apr 04, 2005 1:43 pm

GSM (Cingular)

Post by Westronics » Fri Sep 23, 2005 11:38 am

spymongoose:

Would you consider posting instructions for a GSM phone antenna? I think I might like to give that a go, but I do not quiet understand how to set it up to be multi-frequency, or how to calculate the correct lenght for the antenna.

It's for GSM in the U.S.; Cingular, to be specific.

I was thinking of doing somethin that I would plug in only when I wanted it - sitting the antenna on my desk at work where I get a very, very flakey in-and-out signal.

If this works, I can then dump my work phone and go to a single device for work & home!

User avatar
spymongoose
PDAPhone Hacker Team
Posts:433
Joined:Wed Jan 05, 2005 10:37 pm
Location:Las Vegas
Contact:

Re: GSM (Cingular)

Post by spymongoose » Fri Sep 23, 2005 11:56 am

Westronics wrote:spymongoose:

Would you consider posting instructions for a GSM phone antenna? I think I might like to give that a go, but I do not quiet understand how to set it up to be multi-frequency, or how to calculate the correct lenght for the antenna.

It's for GSM in the U.S.; Cingular, to be specific.

I was thinking of doing somethin that I would plug in only when I wanted it - sitting the antenna on my desk at work where I get a very, very flakey in-and-out signal.

If this works, I can then dump my work phone and go to a single device for work & home!
I am developing such an antenna, and its not easy. The 3 center freqs you should think about are of course 850 mhz, 1800 mhz, and 1900 mhz. A 1/2 wave dipole for 1900 would also cover 850 as a 1/8 wave doublet, meaning because 850 is half of 1900 it is a harmonic and would work to a lesser extent. 1800 would also have a chance of working on a 1900 antenna, just not as well. How much poorer these freqs would work on a 1900 antenna is unknown, whitch is why im building a prototype and am going to send it to a gsm buddy of mine for testing.

If they dont work, I would have to build a few resonant tank circuits to try and isolate/amplify the desired freq range. I'd rather not do that tho.

If you want, try building and testing a sprint 1900 antenna on your gsm phone, and let me know how it works. Also stay tuned for the "spy" 2.0 antenna, you will be able to use the same materiels but have it in a clip free design that plugs into your phone.
Talkabout T900 --> Handspring Visorphone --> Kyocera 7135 --> Treo 600 --> Apache PPC 6700 -->Nokia 770
http://www.shadowmite.com http://www.ppc6700users.com

User avatar
spymongoose
PDAPhone Hacker Team
Posts:433
Joined:Wed Jan 05, 2005 10:37 pm
Location:Las Vegas
Contact:

Post by spymongoose » Sat Sep 24, 2005 9:50 am

Well the PPC 6700 has a different connector than the treo's, i hadnt counted on that, it makes getting parts a bit harder. I dont know what it is, its different thatn the major ones. Still fiddiling with the prototype 2.0 antenna. The PPC 6700 seems to have better reception on the stock antenna than the 650 does, by a tad... actually it was hard to make it lose signal in my testing grounds... We shal see.
Talkabout T900 --> Handspring Visorphone --> Kyocera 7135 --> Treo 600 --> Apache PPC 6700 -->Nokia 770
http://www.shadowmite.com http://www.ppc6700users.com

User avatar
spymongoose
PDAPhone Hacker Team
Posts:433
Joined:Wed Jan 05, 2005 10:37 pm
Location:Las Vegas
Contact:

Post by spymongoose » Mon Sep 26, 2005 6:52 am

It seems that the port on the back is indeed a FME male, it just looks wierd. Anyhow I have ordered a cable ($15!!!) and I will be able to confirm it soon. I will put pics up on the wiki as soon as I can, and try to make it clear (Treo = FME female, PPC 6700 = FME male) so that folks order the right one. The FME male is much more common it seems. Hopefully I have two prototypes and the wiki done (one FME male, one FME female) by monday next week.
Talkabout T900 --> Handspring Visorphone --> Kyocera 7135 --> Treo 600 --> Apache PPC 6700 -->Nokia 770
http://www.shadowmite.com http://www.ppc6700users.com

Post Reply