RE: " No tuner made can reject multipath." Discuss?

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Posted by Neff on December 29, 2011 at 11:37:43

In Reply to: " No tuner made can reject multipath." Discuss? posted by Timbo in Oz on December 28, 2011 at 16:41:31:

No tuner I am aware of will reject all multipath. However some tuners have a more selective RF front-end than others including a capature ratio. Capature ratio is rejection of a less strong signal on the same frequency. A capture ratio specification of 2dB is if the stronger signal is 2dB stronger than a close nearby frequency, the weaker signal will be surpessed 30dB. Usually the 30dB rating is the standard reference. I do not believe capature ratio will have much effect on multipath that is on the same frequency. Capture effect is cool on FM broadcast, totally uncool an aircraft communications as capture effect could stop critical communications. Thus, aircraft uses AM (amplitude modulation).

The best multipath reducer is a highly directional antenna. The next best is a simple rabbit ear antenna. The rabbit ear antenna can take advantage of the common FM station transmitted circular polarization by rotating to exploit deep response nulls being circular right, circular left, horizontial and vertical.

An indoor rotatable rhombic would be cool. Just never calculated the size required.

I use the inexpensive rabbit ear antenna with selective capacitor switch (tuning) as part of the kiss (keep it simple) plan. I am fortunate to have good reception in my area (both locations).

On the horizon are patents that use processing to eliminate some multipath. However, I am not sure if it may end up degrading the sonics.

One can always select mono as it is less disturbed with multipath vs stereo.

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Follow Ups Full Thread

Topic - " No tuner made can reject multipath." Discuss? - Timbo in Oz 16:41:31 12/28/11 (16)

RE: " No tuner made can reject multipath." Discuss? - stellavox 06:10:42 01/04/12 (0)

You're correct Tim..... - kootenay 00:29:47 01/04/12 (2)

RE: You're correct Tim..... - Brian Levy 12:41:08 01/30/12 (0)

If signal is strong 'cos it came from a directional antenna it 's unlikely to have much multipath content - Timbo in Oz 00:40:05 01/04/12 (0)

A most interesting thread. Thanks! (nt) - 1973shovel 10:24:34 01/01/12 (0)

Maybe no 'consumer' tuner... - AbeCollins 19:41:05 12/31/11 (1)

SDR? Yes I have heard about it. - Timbo in Oz 16:43:51 01/01/12 (0)

I'm going to agree - Awe-d-o-file 09:16:52 12/31/11 (0)

RE: " No tuner made can reject multipath." Discuss? - centaurfm 14:37:41 12/30/11 (2)

Hybrid Digital is very lossy digital, it isn't high definition by any assessment. - Timbo in Oz 16:24:02 12/30/11 (1)

Further digital RF either works or it doesn't, cell-phones and all else! - Timbo in Oz 01:07:08 01/04/12 (0)

RE: " No tuner made can reject multipath." Discuss? - Neff 11:37:43 12/29/11 (0)

RE: " No tuner made can reject multipath." Discuss? - hahax@verizon.net 21:42:02 12/28/11 (3)

AFAIK rejecting multi-path is a phase issue so capture ratio isn't much of a help - Timbo in Oz 01:42:28 12/29/11 (2)

Capture ratio is certainly relevant in reducing multipath - AbeCollins 13:00:23 12/31/11 (1)

It is my experience that a directional antenna with gain always sounds better than anything else - Timbo in Oz 01:03:55 01/04/12 (0)

Follow Ups

RE: " No tuner made can reject multipath." Discuss? - Neff 11:37:43 12/29/11 (0)

RE: " No tuner made can reject multipath." Discuss?

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