Re: Car alarm question...


"Matt Ion" <soundy@xxxxxxxxxxxxxxx> wrote in message
news:Oy1Ye.530559$s54.332331@xxxxxxxxxxx
> Bruce Chang wrote:
>
>> "joe.ker" <joe.ker@xxxxxxxxxxx> wrote in message
>> news:RQQXe.1833$Az1.980@xxxxxxxxxxx
>>
>>>That length of wire is tuned to the frequency of the transmitter and
>>>Clifford says not to extend it. With that being said, I have added 2 foot
>>>of wire to some Clifford alarms and the range did get better. it will not
>>>hurt anything to try.
>>>
>>>"Matt Ion" <soundy@xxxxxxxxxxxxxxx> wrote in message
>>>news:d4MXe.525832$s54.42634@xxxxxxxxxxx
>>>
>>>>Since I can't seem to find a rec.alarm.car or anything similar, I'll ask
>>>>here...
>>>>
>>>>I have an old Clifford XL1000 alarm in my car. Range on the remotes
>>>>sucks green giblets.
>>>>
>>>>Since the antenna on the brain is receive-only so I don't have any sort
>>>>of transmit-impedence-matching to worry about, can I successfully extend
>>>>this thing with, say, a piece of wire up into the top of the dash, or
>>>>maybe up the a-pillar into the header, or in some similar way improve
>>>>the range?
>>>>
>>>>
>>>>---
>>>>avast! Antivirus: Outbound message clean.
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>>>>avast! - copyright (c) 1988-2005 ALWIL Software.
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>>>>
>>>>
>>>>
>>>
>>>
>>
>> If I understand antenna design correctly, the antenna should be a quarter
>> wavelength in length. If you were to extend the antenna, you would need
>> to extend it in increments of a quarter wavelength. If you don't, then
>> the antenna is less effective but not ineffective. If the wavelength is
>> equal to 20 inches, then you would need to make an antenna of 5, 10, 15,
>> 20, etc. inches in length.
>
> D-oh <smacking myself in the forehead> I knew that. Dummy me.
>
> Guess ideally then I need to measure the existing antenna and lengthen it
> by the appropriate factor of 2/4/8/16/etc.
>
>

The appropriate factor is any integer, it doesn't have to be a multiple of
2.

-Bruce


.

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