RF filter for 860 MHZ PS Band

[cpetraglia]

Does anyone sell a band pass filter that would reject the lower 800 and higher 800 cell frequencies. I am in a situation that in order to point my yagi at the closest (and tallest) tower for my local system. (P25 Ph I). I am aming right through a cell tower that is less than a mile from me. I have researched the FCC and obtained addresses for the 6 sites. This one gives me the best CC and voice reception with occasional interferance that raises he** with the voice reception.
I have searched many manufactures and found nothing in this range.

Thanks, Chuck

[KevinC]

Contact Dale at PAR Electronics, he can custom-make a filter for you at a reasonable cost.

PAR Electronics | Filters for the commercial 2 way market, MATV, FM broadcast, laboratory, marine industry, amateur radio, scanner and short wave listening enthusiasts

I've purchased numerous filters from him, his customer service is awesome and his filters are built well and perform well.

[cpetraglia]

Thanks so much. I'll give it a try.

Chuck

[cpetraglia]

Thanks KevinC. I have ordered a filter from Dale. He was very helpful and quick to respond.

Chuck

[KevinC]

Be sure to let us know how it works once you receive it and have a chance to try it out.

[benbenrf]

Decent good 1quality band pass filters cost money - they can be seriously expensive compared to what consumer grade scanners/receivers cost.

An excellent alternative for sourcing band passfilters is to go onto eBay and type in "band pass filters" - search All Catorgories of eBay. You will come up with a list of literaly 100's of used/2nd hand band pass filters.

Ban Pass fitlers are normally described by way of given their centre frequency first, followed by their bandwidth more often than not in a +/- Mhz formatt (i.e. how many Mhz wide each side of the centre freq). The bandwidth will often given as a -3dB figure, meaning by how much the signal strnegth contained within the band pass will drop off at the edges of the pass band.

Keep in mind that once installed this type of filter will allow you to receive nothing else - except that range or bandwidth within the band pass. If you are also, or still wanting to receive freq's not only contained within the band pass but below the lower 800Mhz range and above the higher 800Mhz cell range (i.e. it is only those 2 sets or bandwidths that you seek to eliminate and nothing else), then it is not a band pass filter you want, but a couple of notch or band stop type filters. Notch or band stop filters will allow you to eliminate certain frequencies or frequency ranges contained within your overall listening bandwidth. You listen right across the 20Mhz - 1200Mhz bandwidth but wish to eliminate say 3 or 4 bandwidths contained within your overall listening range because there are strong transmissions centred on them that bleed across and interfere with everything else e.g. you wish to get rid of 341Mhz - 352Mhz as well as 512Mhz - 513Mhz as well as 800Mhz - 825Mhz and lastly 874Mhz - 883Mhz ..... or some similar combination of problimatic bandwidths - Notch or band stop filters are what you require for this latter problem, not band pass.

Keep in mind as well, that as said above, filters connected in-line in your coax run = received signal strength loss, and as you add freq's to eliminate your losses will quickly start to rise. -3dB may not be to bad, but add just one more band stop filter which also has -3dB loss and you are now right down on signal strength by 75%!

It can all pretty quickly add up to having to then invest in a preamp as well

[WayneH]

Originally Posted by benbenrf

An excellent alternative for sourcing band passfilters is to go onto eBay and type in "band pass filters" - search All Catorgories of eBay. You will come up with a list of literaly 100's of used/2nd hand band pass filters.

For most scannists they aren't going to have the equipment or know-how to adjust these. That's where the PAR filters come in to play.

[benbenrf]

Originally Posted by WayneH

For most scannists they aren't going to have the equipment or know-how to adjust these. That's where the PAR filters come in to play.

No need to adjust, they are manufactured to fixed frequencies, roll-offs and bandwidths - just choose one (0r more) that fits the freq/bandwidth that is required.

[WayneH]

Originally Posted by benbenrf

No need to adjust, they are manufactured to fixed frequencies, roll-offs and bandwidths - just choose one (0r more) that fits the freq/bandwidth that is required.

Finding one specific to one's use (or the OP's in this case) is like finding a needle in a hay stack. There are a TON of filters on ebay and even searching for "800 band pass filter" results in nothing useful.