| Author |
Message |
    
Keithinatlanta
| | Posted on Monday, November 24, 2003 - 10:22 pm: | 
|
What is the purpose of the Low Pass Filter?
Thanks.
Keith in Atlanta |
Cactusjack
| | Posted on Tuesday, November 25, 2003 - 12:51 am: |
|
A low pass filter is designed to cut off or attenuate undesired frequency harmonics above a given frequency. Say a low pass filter has an attenuation of 80 db at 35 Mhz. This means that any harmonic the radio transmits at or above 35 Mhz will be attenuated or cut by 80 db or better but any thing under say 30 Mhz will pass freely.
These harmonics are multiples of a given frequency. In other words the harmonics will be 1,2,3 etc. times the frequency the radio is operating on. Say you are on channel 13 (27.115). The harmonics will be at 54.230, 81.340, 108.460 Mhz etc.
Anyway thats the way I understand it. If I am wrong someone please correct me. |
Ironmask
| | Posted on Tuesday, November 25, 2003 - 6:46 am: |
|
Keith,
To simplify, the harmonics refered to are what causes problems with TV's, Telephones or other receiving type electronics.
They are comonly refered to as TVI filters.
Television interference filters. |
Ca346
| | Posted on Tuesday, November 25, 2003 - 1:29 pm: |
|
Keith:
I've got two. One on each radio system. One from COPPER and one from Vectronics. They are my INSURANCE to maintain good neighbor relations.
They must be working.... Nobody's been knock, knock, knocking at my door... |
Ss8541
| | Posted on Tuesday, November 25, 2003 - 9:42 pm: |
|
keith,
think of them(filters) as a bouncer at your favorite club. they are there to keep the troublemakers and trash from making it through the door.
you could also call them 'peacekeepers' as they have been for ca346. |
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