Equis
Premium
join:2005-03-18
Australia
| 5gz Cable Hello,
Do you need special cable for 5ghz installs or will the normal LM400 stuff work fine?
I did my first 5ghz install and it didn't work well at all, I decided to go to 2.4 and to my suprise I changed the antenna's to 2.4 grids and have the same snr that I had with the 5ghz panels (really bad) this made me wonder if the cable was not letting the 5ghz pass
Thanks
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 cmaenginsb
Premium,MVM
join:2001-03-19
Palmdale, CA
| Re: 5gz Cable No, LMR-400 is fine with 5ghz, however it is more sensitive to improperly terminated connectors and nicks and bends. It's not until you get to stuff like 7/8" heliax that 5 ghz can't be used.
As to your signal strength, while the panels might have the same gain as the grids, 5 ghz has more loss over distance so your signal strength would be the same.
I recommend finding a link calculator like the one on electrocomm (which I hate but since YDI took there's down it's my backup) and seeing what the RSSI/SNR should have been for both 2.4 and 5 ghz. | |
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John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp | Download the ElectroComm catalogue. It has a section in it for cable and the specifications for each type. Loss per 100 feet at a variety of frequencies is one of the spec's.
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Equis
Premium
join:2005-03-18
Australia
| Thanks Guys,
It just seems strange I couldnt get a 500ft link working with 5ghz.
When I changed the antennas to 2.4 (nd left radio on 5ghz) I saw no degrade, thats what made me thin it was the cable
This is what I was using, It say LMR400 "Style" »www.wisp-router.com/product_info···s_id=356
When I emailed wisp a week ago they never answerd (they are normall really good)
Thanks
Rhys | |
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cmaenginsb
Premium,MVM
join:2001-03-19
Palmdale, CA
| Were you using mini-pci cards? Did you say you had the radios running at 5 ghz but the antennas were 2.4, what cable did you use with that.
The wisp router cable should work fine. If you're using mini-pci most likely it is the u fl pigtail to blame, the tolerances on those just suck, which is why I'm glad the new 400 mw radios have mmcx as an option. | |
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 | GuyS25
join:2003-12-26
England
| Re: 5gz Cable said by cmaenginsb  : If you're using mini-pci most likely it is the u fl pigtail to blame, the tolerances on those just suck, which is why I'm glad the new 400 mw radios have mmcx as an option. I'm not sure if you've seen it, or even participated, but there is a very long thread on this on the starOS board. After a lot of detailed testing, it has been concluded that it is not the U.FL connector that's the problem but the compatibility between the very small coax that must be used and the N-Type.
These pig tails use a different manufacturer's connector (not Hirose) which allows a larger coax to be used. Some people have seen up to 8dBm improvement at each end of the link by using these pig tails:
»www.allrfcables.com
I have just received some U.FL to N-Type and have not tried them yet but they are certainly a lot more substantial than the ones I have been using to date.
HTH.
Guy
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| | Equis
Premium
join:2005-03-18
Australia | Re: 5gz Cable I did a search on the star-os forum but not sure if I'm looking at the correct one.
Would you be able to post a URL to the topic?
What about the MMX to N are they any better?
Thanks Heaps!! | |
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Equis
Premium
join:2005-03-18
Australia
| Yep, They are the mpci cards with the u.fl connectors.
I started off using all 5hz radio & antenna, because the radios are 5ghz & 2.4 ghz I changed to 2.4 antenna's (before I switched the radio over to 2.4)
I was using the same cable each time.
Thanks | |
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Beebe
join:2002-10-25
Beebe, AR | Re: 5gz Cable Make sure you are using the correct u.fl connector on the card. A lot of them have two for diversity, and sometimes you can choose the primary port from software. | |
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cmaenginsb
Premium,MVM
join:2001-03-19
Palmdale, CA
| I would check to make sure you're using the right connector as beebe mentioned. So you swapped out the antennas and even with the radios on 5 Ghz with the 2.4 antennas the link worked? If that's the case then I would look at the antennas.
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CCNA, Comtrain Certified Tower Climber | |
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cmaenginsb
Premium,MVM
join:2001-03-19
Palmdale, CA
| Thanks for the info Guy. Personally I don't use Star-OS so I wouldn't have seen a thread there.
That does make sense and of course any negative effects will be far worse the higher the frequency you use. | |
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GuyS25
join:2003-12-26
England
| That is the case on frequency. It was found that the effect was negligible at 2.4GHz, less than 1dB IIRC. Here's the link:
»forums.star-os.com/showthread.php?t=3495
Be sure to put on a fresh pot of coffee before clicking. | |
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John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
 ·CenturyLink
| Re: 5gz Cable said by GuyS25 :Be sure to put on a fresh pot of coffee before clicking. That's the kind of interpersonal advice and consideration that makes this forum work...
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| | Hydro27405
join:2004-12-31
Stillwater, MN
| Re: 5gz Cable I was one of the people testing in the StarOS forum.
I just changed another pigtail out last week, the standard one was 12" of 1mm coax and the new ones I use are 6" of 1.8mm cable. At 5.8Ghz the customer went from -74 to -68 so there is a considerable differance.
I use 3' of LMR400 at each install, the one thing I do see that a lot of people forget to do is use emery cloth on the center conducter before crimping the center pin on. This makes a huge difference at 5.8 and 2.4.
Hydro | |
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John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
·CenturyLink
| Re: 5gz Cable said by Hydro27405 : I use 3' of LMR400 at each install, the one thing I do see that a lot of people forget to do is use emery cloth on the center conducter before crimping the center pin on. This makes a huge difference at 5.8 and 2.4. I have mentioned this before...that installation in general, and installation of connectors in particular, is something that deserves the utmost care.
Every little thing matters...a lot.
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superdog
I Need A Drink
Premium,MVM
join:2001-07-13
Lebanon, PA
| said by Hydro27405 : I use 3' of LMR400 at each install, the one thing I do see that a lot of people forget to do is use emery cloth on the center conducter before crimping the center pin on. This makes a huge difference at 5.8 and 2.4. Hydro Nothing against what You have said?, But wouldn't even THINK of crimping a 5.8Ghz connector at all?. I would solder every center pin. I don't even use crimp on @ 2.4Ghz because I have had to many problems early on. IMHO, that is just one more thing that will make me get out of bed at 3AM??:)
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»www.wavecrazy.net Join WISPA today! »www.wispa.org/ | |
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| | | | GuyS25
join:2003-12-26
England
| Re: 5gz Cable Hmm...I could be totally wrong on this but I believe that a crimp generally performs better at 5GHz frequencies. Times Microwave's own EZ range of connectors use a spring clamp arrangement for the centre conductor.
Of course, there are crimps and crimps. The correct dye is essential for a consistently high quality crimp.
I've also heard that around 5GHz everything should be silver soldered.
Anybody know much about this area before I throw out any more curve balls? | |
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John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
·CenturyLink
| Re: 5gz Cable said by GuyS25 :Anybody know much about this area before I throw out any more curve balls? My opinion is that you should use pre-manufactured cable assemblies from a reputable manufacturer. The reason for this is that they are in the business of making cables and do it "day-in-and-day-out"...therefore they are very good at it. They have the proper tools, training and equipment to accomplish the task. They are certainly very much better at it than someone who cuts a couple of fittings a week.
That being said...! I realize that field assemby is sometimes required.
If you have to cut a fitting in the field, the same "rules" should apply. Use the best tools, materials and techniques. I think that your observation regarding the use of the proper crimp die is correct. I believe that soldering them helps to keep out the air and reduce the oxidation that will form at the crimp interface over time.
It is necessary to have every metallic part clean and shiny-bright before assembly. Touching things with your fingers and getting the oil on them prior to assembly is just asking for trouble. Appropriate solvent cleaners are recommended. Make sure that they are compatable with the materials and do not cause degradation. I apply them very sparingly with dropper bottles and swabs, and use laboratory grade "clean-wipes". They are not very expensive...
I used to build assembly workstations for the satellite assembly facilities at NASA Ames in Sunnyvale, CA and for Loral Space Systems. I was very interested in watching how the technicians assembled every piece of equipment. Everything related to the assembly is very exacting, because they only get "one chance" to do it right. If it fails after launch....well, never mind! Ain't gettin' fixed now.
My boss used to say that it took me twice as long to install anything compared to the other guys. He would send me out to fix their installations after they broke down. I finally got tired of that...and I went back to the office and asked where these other guys were.
"Oh, they're out making installations...!"
I told him that I wasn't going to fix anyone else's install anymore, that if it failed that they had to fix it themselves, otherwise they would never know what they were doing wrong. The boss thought that was a good idea and started doing that.
The other people "whined" that they didn't "have the time" to go back and fix the "problems"...
Ha-ha...!
Things got better after that.
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Equis
Premium
join:2005-03-18
Australia | Thanks
I think I'll use the MMX Connection & see what happens | |
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