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| jbarrington |
 Posted: Fri Jan 11, 2008 6:29 pm Post subject: Garage remote signal booster |
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Forum Freshman
Joined: 13 Feb 2006
Posts: 14
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I have an easy project that I wanted to try, but I wanted to bring it here first to see what the general feeling was about it working.
Off and on, I’ve wanted to find something that would boost my garage remote. I’ve seen projects that involve soldering variations of extended antennas, but I really didn’t want to modify the remote.
I was searching today and it dawned on me that I might be able to use an old analog 120 volt television signal booster to do the job. Sort of like a repeater.
What I was thinking was to take the signal booster and place it in the garage. Next , I would have a cheap antenna feeding into the input and the have another cheap antenna being fed from the output.
When a weak garage remote is pressed, the faint signal is boosted up to where the garage opener could then see it better and then react. |
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| Guest |
| Posted: Fri Jan 11, 2008 6:33 pm Post subject: |
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| What frequency are we talking here? you cannot just string things together, at high frequencies (and low) there's a little thing called impedance matching, get that wrong and you could blow things up, or get less real power out than when you started. |
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| jbarrington |
| Posted: Sat Jan 12, 2008 7:51 am Post subject: |
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Forum Freshman
Joined: 13 Feb 2006
Posts: 14
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| Megabrain wrote: |
| What frequency are we talking here? you cannot just string things together, at high frequencies (and low) there's a little thing called impedance matching, get that wrong and you could blow things up, or get less real power out than when you started. |
Sorry, I became so fixated on that this project might just have the possibility of working that I forgot to mention a few little details.
First, I noticed online that garage door openers appeared to operate between 300 MHz and 400 MHz megahertz. However, I did go ahead and looked up my FCC frequency just to be sure. I looked on the back of my remote control and wrote down the FCC ID (HBW 1630).
Next, I went to: https://fjallfoss.fcc.gov/oetcf/eas/reports/GenericSearch.cfm to research my garage door opener and entered the first three characters of FCC ID into the “Grantee Code” area of the form and the remaining characters of FCC ID into the “Product Code” area. The search results came back as 315.0 for the upper and lower frequency in MHz.
Depending on the model and manufacturer, it seems that the typical generic CATV signal booster generally operate in 50 MHz to 900MHz range for the upper and lower ranges. |
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| Guest |
| Posted: Sat Jan 12, 2008 7:57 am Post subject: |
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as well as the frequency you also need to know the type of modulation, eg AM (changing the level of the power output) or FM changing the frequency.
ANother point is it currently operating as good as the manufactures data?
If some guy down the road has a similar system are you gonna end up opening all the doors in the street?
I think there is a power limit on these these things to prevent it.... |
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| jbarrington |
| Posted: Sat Jan 12, 2008 9:04 am Post subject: |
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Forum Freshman
Joined: 13 Feb 2006
Posts: 14
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At this point, without knowing any other details, is that these CATV boosters will jump up the signal anywhere from 12db to 30db (some of them are adjustable). Beyond that, I don't know anything else at this point.
Garage door openers (from what I understand) work in an inactive military band that can be used at anytime by the military if it is deemed necessary. If fact, a while back there was a news report that one small town/city reported that residents complained their doors were opening and closing like crazy. It was later found that the military had used that signal band area for something, but I think they weren't suppose to for some reason. |
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| Guest |
| Posted: Sat Jan 12, 2008 9:14 am Post subject: |
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I'm in the UK, you are (I guess in the US), It is not about how many DBs your CATV booster is rated at, if the input signal is too large the output could end up being less!
I would guess that the transmitter of the remote already puts out more than a CATV booster can, do you know what the max output of the CATV is in DBmW ? and it's output impedance? you will also need to know this for remote.
It is a bit like being asked "If this motor will drive this generator" without being given any details. |
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