Your Digital Media Has Never Looked So Good

 
RocketRanger125
Topic Author
Posts: 6
Joined: Sun May 13, 2007 10:30 pm

Signal Quality with Cantenna for ROKU

Sun May 13, 2007 11:03 pm

I use my ROKU M1001 in a detached garage which places about 100' between my ROKU and router. Signal strength was OK (-87dB) with frequent rebuffering several times during playback of even 128K MP3s.

Out of frustration, I sought solutions. Purchased a better router with external antenna options. Added high gain omnidirectional antennas. Relocated all equipement. Tried all avail channels. All resulted in no better performance...........

Decided I would try a directional antenna. I assumed that the signal strength was "OK" since I could play 256K MP3s a few at a time every few listening opportunities without problems. The rebuffering I blame on the busy inner city wireless noise. (IE: 2.4Ghz Baby Monitors, cordless phones, and other.....)

Since I had other devices that roamed the house, I did not want anything other then a omni-antenna on the router end. I decided that the best place for the directional antenna was on the ROKU itself. This would give better signal strength and lower interfering noise levels. Improved signal to noise ratio.

Did searches on the internet for homemade directional antenna solutions. Found the "Cantenna" idea to be right at the appropriate price level since I didn't know if it would workout. It worked excellant!! Previously, I was in the upper 80s for signal strength and now I run from 58 to 62 consistently with no rebuffering during a few days of listening. This was unheard of for my setup.

How to get there? This is a tough one. What I am suggesting should not be performed if you intend to keep any kind of warrenty with ROKU-Labs. This will indeed toss your warrenty since you will be violating the guts of the unit. NOT Recommended for anyone other then techs, engineer, or your super-geeks. Find someone handy with a soldering iron and proper ESD practices. Pay them to do the mods!

Start by searching the web for details on building the "Cantenna" itself. I used a coffee can and "SMA" style RF connectors with low loss RF coax cable. The COAX cable is where not to skimp om quality. 2.4Ghz is very high frequency and very sensative to the media used for transmission. Improper quality COAX and\or too much length anf you'll get worse performance then before the mods.

Very brief:
1) Remove Endcaps, Metal Shell, and Plastic Cage for MainBoard
2) Remove bright blue "WTC" chip antennas
3) Solder COAX cable to proper pads in place of "ANT2" chip antenna
4) Mount or connector on endcap or run cable straight out. (Less Loss)
5) Build Cantenna (www.wikipedia.org)
6) Connect Cantenna to ROKU
7) Align\Aim your antenna on a stiff mount (Be creative...)
8) Enjoy skip free music from further locations!!!!

If you would like photos of my setup, and\or tech info. Let me know!

Email Me: RocketRanger125@yahoo.com


-Rocket
 
RokuMike

Mon May 14, 2007 5:05 pm

Hahah! Well, that must be interesting to see.

FYI for those reading this thread, apart from the obvious "warranty void if you even think about doing this" caution, I just want to point out that a signal strength of -87dBm is definitely not OK. It's borderline unusable (which certainly accounts for your wanting a different antenna solution!)
 
davwebb
Posts: 352
Joined: Wed Aug 10, 2005 7:47 am

Cantenna

Mon May 14, 2007 5:27 pm

Also, be very careful with ESD discharges after it is hooked up. The unshielded metal antenna is a direct pathway to oblivion. I did a similar mod with the M1000 CF card and an Omni antenna a while back. It vastly improved the performance, but I went to a wired setup eventually.
 
RocketRanger125
Topic Author
Posts: 6
Joined: Sun May 13, 2007 10:30 pm

ESD and External Cantenna

Mon May 14, 2007 7:59 pm

Thanks for the inputs!

-87 was a very poor experience. With the detached garage and no reasonable means to get a wire out to this location, making a wireless solution work was an obviously very attractive. Trust me, I love wired!!

ESD should always be considered with a project like this. Especially when you are completely on your own when bad things happen. Please involve someone who knows electronics etiquette. :lol:

The finished cantenna is very safe ESD-wise. The ROKU round metal enclusure is at the same ground potential as your antenna ground. Touching the can is the same as touching the shell of your ROKU. The ROKU shell was designed to withstand heavy ESD hits from casual users during normal handling. Handling the antenna can is no different.

Exceptions that I understand would compromise the unit ESD-wise:
1) Mounting the antenna outside where lightening is a possibility. This is a common failure for and RF equipment with outside mounted antennas. Cable inserts are available to protect your investment should you have a desire to setup a antenna outside for some real distance from your music collections. (SEVERAL MILES are possible with homemade cantennas on both ends!!) Little is lost by mouting your antennas in the attic, unless you have a tin structure. Arghhhhhh

2) Direct hit to the antenna element itself. This requires that you touch the center of your connector ot the uprigth element in the can itself. Both are unlikely. ESD damage still seems unlikely.......

Be ESD careful during construction. During use, I vote "No Worries"!!!


Luck with your cantennas!!
 
RocketRanger125
Topic Author
Posts: 6
Joined: Sun May 13, 2007 10:30 pm

Cantennas and Long Runs

Mon May 14, 2007 9:49 pm

Uses: Any remote building that could use some tunes!!

Distance: Several miles is very common for cantennas on both ends. (Router and ROKU) The long distance examples are cheap homemade cantennas used in line-of-sight testing without ANY obstructions. (Trees\Buildings\Windows) I would think that a good mile is still possible with good aim with antennas indoors. (Attic perhaps?)

Cabling: Long cable runs are evil for RF signals. Your better off keeping your cables shorter then going long for better placement unless you purchase the more costly coax cables. Consumer wireless equipment does not transmit much RF juice. Every bit is precious.

I have yet to test the effects of using different ratings of cable on my signal strength in my setup. If there is interest in this thread, I will.... There is definite value in keepin the cost low and success high!

Router End: I use a Linksys unit that makes custom antenna interfacing a snap. The 2 RF connectors on the back of the unit allow some serious versatility.

Example:

Antenna#1 can be used with the original omni-antenna for use with roaming inhouse equipment like laptops.

Antenna#2 can be connected to your cantenna and aimed towards your ROKU cantenna a half mile+ away.

Note that I don't use anything more the OMNI-Antennas on my router for my setup. My only change is the cantenna on the ROKU end. This is the end that lacks the most in antenna ability and sources on noise from the environment\neighboors.
 
mas
Posts: 281
Joined: Tue Dec 05, 2006 11:46 am

Tue May 15, 2007 10:57 am

wouldnt it have been the easier way to replace only ONE of the usually 2 antennas from the router with a directional antenna, leaving the other with the omni? That should also kind of work without all the soldiering. Though it almost certainly wont look so cool.

And also building a cantenna may be fun, but for 30 bucks you also get a nice commercial directional antenna, so the price isnt a real argument if you value your own time anything worth.
Those who sacrifice freedom over safety deserve neither.
 
RocketRanger125
Topic Author
Posts: 6
Joined: Sun May 13, 2007 10:30 pm

Router End Directional and Commercial Antennas

Wed May 16, 2007 6:22 pm

Quality of a connection is both strong signal and little OTHER signals (Noise). Placing the directional on the ROKU end of business gives me the best connection. Strong signal and low noise.

I also don't want a stronger signal from my router blasting accross the neighborhood. More comforting to leave the least device with the least security risk with the long distance antenna.

As far as cost... Coffee cans are sitting around most homes. Quality coax cable is cheap in 1-2foot lengths. No connectors are required* in the cheapest cantenna setups. (Direct connect ALL) The technical part of soldering is indeed hard to avoid.

LMR-200 is less then $1\ft and has <.5dB\1m

Approx gain of 20dB with the cantenna. The cable loss is minimal.... Not sure how ethernet RG58 would do at 2.4Ghz. I wouldn't recommend it....

For RF materials, try: www.Pasternack.com

I was fortunate enough to get some scrap LMR-200 from work. My connectors were also used\free. Not all will be so lucky.
 
andelscott
Posts: 5
Joined: Mon Apr 16, 2007 8:55 am
Location: UK

Re: Router End Directional and Commercial Antennas

Thu May 17, 2007 7:20 am

RocketRanger125 wrote:
Not sure how ethernet RG58 would do at 2.4Ghz. I wouldn't recommend it....


I agree - my data book says (at 3GHz) losses are 37.5dB / 100 ft (RG58C/U variant is 45dB / 100 ft). The aerial gain would be all but thrown away unless it is a very short length of feeder.

The choice of connectors also warrants consideration - SMA type seem to be popular for low microwave/high UHF applications although BNC is repoted as good to 10GHz.
---
Andy
 
RocketRanger125
Topic Author
Posts: 6
Joined: Sun May 13, 2007 10:30 pm

Data Book on COAX Cable

Thu May 17, 2007 3:40 pm

If the antenna gain is as good as 20dB and length of cheap\junk\FREE RG58(/U) is 3 feet in length, you would still yield over 15dB in gain. Still would rather seek appropriate cable, but in a pinch!! BNC Connectors are cheap and easier to terminate with readily available cheapo tools then the other RF connectors on the market. A RG58 setup with COAX with BNCs would do the trick.......

Heck, I think most of the large home improvement stores carry the needed supplies. The hardest part of RG58 is termination in the ROKU itself. Pads are small and the COAX is stiff. I used a very short piece of white LMR-200 cable that was terminated with flanged surface mount SMA connectors. I just cut it a couple inches long, stripped, soldered and mounted the connector.

I am interested in your databook? Is it from a supplier, or is it a electronics mini-notebook type of reference?
 
RocketRanger125
Topic Author
Posts: 6
Joined: Sun May 13, 2007 10:30 pm

Pictures of My Cantenna Setup

Thu May 17, 2007 4:04 pm

Here is a link to my cantenna setup:
http://www.visi.com/~shanefoss/Cantenna
 
andelscott
Posts: 5
Joined: Mon Apr 16, 2007 8:55 am
Location: UK

Re: Data Book on COAX Cable

Thu May 17, 2007 5:23 pm

RocketRanger125 wrote:
I am interested in your databook? Is it from a supplier, or is it a electronics mini-notebook type of reference?


I suppose the latter is a good description: 244pp 'Radio Data Reference Book' published by Radio Society of Great Britain - quite an eclectic mix of data, conversion tables/charts and useless information....

HTH
---

Andy
 
BubbaDog
Posts: 92
Joined: Tue Jan 23, 2007 11:58 am
Location: Houston, TX USA

Fri May 18, 2007 10:38 am

Can the coax connector be wired in parallel with the existing chip antennas to provide an 'either/or' setup to allow use of the internals when I've got the M1001 indoors or the Cantenna when I take it out on the back deck? The best of both worlds and all that....

B'Dog

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