ehenry
join:2007-11-07
Fairbury, IL
| Will this hurt my radio?
I installed a very short (less than 1/8 mile) link with a set of Tranzeo 5.X radios. The power is all the way down and the signal is still -26. Is there another way to correct this without pointing the antenna away? Will this harm the radio as is? |
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Chele
join:2003-07-23 | Change the pol on one of the radios. Make one of the units Vertical pol and the other Horizontal pol. The radios will eventually go deaf if the signal is too strong. |
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Jerm
join:2000-04-10
Richland, WA | Anyone know at what point damage might be done to a radio? -40 and higher? What might be safe? |
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John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp | reply to ehenry
Tilt one of them up to the sky slightly until the signal strength is where you want it.
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A is A |
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shorthairedp
join:2005-11-21
united state | reply to ehenry
There was a post here once about imitating free space loss for testing by placing certain materials in front of the antennas, would that apply in a functional environment? |
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ehenry
join:2007-11-07
Fairbury, IL | reply to ehenry
How long do i actually have before this damages the radio? |
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KiZiller
@rr.com
| reply to ehenry
said by ehenry  :How long do i actually have before this damages the radio? That sounds like a lot of power as compared to a typical link, but in reality it is very tiny. My guess is that your caution is unfounded. The AGC in the front end can probably handle 0 dBm or more with no damage. |
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ehenry
join:2007-11-07
Fairbury, IL
| said by KiZiller :said by ehenry :How long do i actually have before this damages the radio? That sounds like a lot of power as compared to a typical link, but in reality it is very tiny. My guess is that your caution is unfounded. The AGC in the front end can probably handle 0 dBm or more with no damage. So in your opinion, there will be no damage? Is there any documentation that you can offer to support this? Not that I don't take opinions, I would rather not harm a customer radio because of a faulty install. |
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EMC_guy
join:2007-10-13
Sharbot Lake, ON
 ·Rogers Hi-Speed
| reply to Jerm
said by Jerm :Anyone know at what point damage might be done to a radio? -40 and higher? What might be safe? The long term damage potential can be clarified by the RF circuit designer at Tranzeo. The typical antenna TX/RX switch is OK with 0dBm level but many 802.11 receiver circuits saturate with much lower RSSI.
This is a result of biasing analog-to-digital converter for very low level signals like -90dBm which occur in indoor wireless LANs. Even with 12-bit ADC circuit, the saturation point will be in the -30dBm range. With 8-bit ADC it will be in the -50dBm range. |
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KiZiller
@rr.com
| reply to ehenry
said by ehenry :... I would rather not harm a customer radio because of a faulty install. Like EMC guy said, a definitive answer would be from the manufacturer. In light of the rest of EMC's post, it sounds like wi-fi microwave radios are not typically designed with automatic gain control of the front end strip. I have no experience with microwave radio circuit design or servicing, so my guess about the potential damage is weakened by what EMC has said.
Get a piece of metal screen wire and fold it over one of the antennas. Adjust the signal to a more comfortable level with a pair of scissors. |
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ehenry
join:2007-11-07
Fairbury, IL
| reply to ehenry
"A signal level like that won’t harm the radios but they won’t operate as well. Another thing that you can do since the power is already turned down is to cross-polarize the radios, this should give you a 20dB reduction in the signal. So mount one radio vertical and the other unit horizontal."
Thanks
Neal Midgley
Support Manager
Tranzeo Wireless Technologies Inc.
Thanks for everyones input. |
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MicroWISP
join:2008-01-30
TX Republic
| reply to ehenry
I'm with John and ehenry on this. I use the same gear and if it's "too loud" at close range I turn it down first, rotate it 180 degrees out of phase second, and if it's still screaming just adjust your downtilt/uptilt so you are looking at some sky instead of directly at the other panel.
By the way, you can go past 0 on the power settings of the Tranzeo gear, they go from 30 positive to 30 negative you know. (-30) Sometimes setting up "negative gain" works for me!
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"Man who say it cannot be done should not interrupt man doing it." |
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lutful
Premium
join:2005-06-16
Ottawa, ON
| reply to shorthairedp
said by shorthairedp :There was a post here once about imitating free space loss for testing by placing certain materials in front of the antennas, would that apply in a functional environment? RF absorbing foams are very expensive and you will need maybe 12 inches deep block for 20-30dB reduction at 5Ghz. It is easier to turn down the TX power or use cross-polarization.  |
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shorthairedp
join:2005-11-21
united state
| No, he was using common materials, but he had an equation for figuring the mass vs frequency to be equivalent to a certain distance, I thought it was in this forum, but i cant find it.
as far as the cross polarization, I imagine its negligible, but wont doing that increase the retransmission rate? |
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RadioDoc
58ef2c0
Premium,ExMod 2000-03
join:2000-05-11
 ·AT&T Midwest
| reply to KiZiller
said by KiZiller :
Get a piece of metal screen wire and fold it over one of the antennas. Adjust the signal to a more comfortable level with a pair of scissors.
Putting a metal screen in front of any transmitting antenna is a horrible idea. |
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lutful
Premium
join:2005-06-16
Ottawa, ON | reply to shorthairedp
Dense HDPE plastics (the kind used in cutting boards) and plain old wood will cut down 5Ghz signal. I recall hearing it was like 3dB per inch of thickness but haven't done any tests. |
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RadioDoc
58ef2c0
Premium,ExMod 2000-03
join:2000-05-11 | Or you could do a professional job of it and use the correct attenuator.
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Toolmaster of La Grange. |
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shorthairedp
join:2005-11-21
united state | how would you attenuate an integrated radio? |
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Get Wireless
join:2007-07-31
| reply to MicroWISP
said by MicroWISP :I'm with John and ehenry on this. I use the same gear and if it's "too loud" at close range I turn it down first, rotate it 180 degrees out of phase second, 180 degrees is not out of phase, 90 degrees is out of phase.
180 degrees puts your Tranzeo unit upside down. |
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Get Wireless
join:2007-07-31
1 edit | reply to KiZiller
said by KiZiller :said by ehenry :... I would rather not harm a customer radio because of a faulty install. Get a piece of metal screen wire and fold it over one of the antennas. Adjust the signal to a more comfortable level with a pair of scissors. That is the most unprofessional thing I have ever heard posted here and I hope no one actually tries it. Anything under 1/4" mesh will block all 2.4GHz radiation and possible damage the internal radios LNA. |
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