Multipath Antenna Problem

[bkushner]

I'm about 10 miles from the towers and have multipath problems where my signal goes from 100 to 65 in a split second..

Can anyone recommend a med range antenna that helps with the multipathing?

 

[jgantert]

I'm not an expert, but I believe if you get a more directional antenna, it will help with the multipath problems. What antenna are you using now?

 

[Tower Guy]

I'm about 10 miles from the towers and have multipath problems where my signal goes from 100 to 65 in a split second..

Can anyone recommend a med range antenna that helps with the multipathing?

How did you determine that the problem was caused by multipath?

 

[Jim1348]

Channel Master CM 4228 8-Bay Bowtie UHF Antenna

[FONT=verdana,helvetica,sans-serif] Channel Master CM 4228 8-Bay Bowtie UHF Antenna (CM4228)[/FONT]

 

[Jim5506]

To help with multi-path you need a more directional antenna, or try turning the antenna left or right to find a stable reflection.

The 4228 has a relatively wide beam, you might look at a RS U75-R for an inexpensive attempt, or the Antennas Direct 91XG for a more expensive solution.

 

[Peter Parker]

Actualy the 4228 hasa realatively narrow beam. 15 degrees is what I usually see quoted for it.

 

[qwert1515]

Both of these links are useful for antenna gain and plot information.

The Channel Master 4228 8-Bay beam plot

Comparing some commercially available antennas

 

[bkushner]

How did you determine that the problem was caused by multipath?

I was told when the signal sits at 100 for 5 minutes then drops to 60 then back to 100 that it's multipath. What are you thinking it could be?

 

[texasbrit]

If you really do have a multipath problem you need a very directional antenna. The CM4228 (and other bow-tie designs) although they are fairly directional they are not good in multipath situations. You really need to be using a yagi design. What antenna are you using at the moment?
Using your zip code at tvfool.com, I see a problem with your stations after the digital transition next year. ABC (WPVI-DT) is shown as moving back to its current analog channel 6 in VHF-lo. This means you will need an antenna that covers VHF-lo as well as UHF.

Your problem could be too strong a signal rather than multipath - if you are using a preamp or an amplified antenna that could well be causing the problem, you should not be using amplification when you are so close to the transmitters.

 

[jgantert]

you should not be using amplification when you are so close to the transmitters.

Not necessarily true. I have a long cable run from the antenna to the TV, and required a pre-amp, even though I am only 15-20 miles from the stations. Turns out I have the smaller ChannelMaster Spartan 3 series (instead of the more popular 7777 pre-amp).

As for the OP, I would think the 4228 would be overkill for just 10 miles out, tho. Plus no way its going to pick up RF 6.

 

[Peter Parker]

Actually I have a 4221 that was able to receive a low power anlaog ch 6 fairly well. So I am not sure how the 4228 would do. I suspect that if is aligned with the others it woudl do fine. But that narrow beam of the 4228 might have an issue if it is too far from the line of sight.

 

[texasbrit]

Not necessarily true. I have a long cable run from the antenna to the TV, and required a pre-amp, even though I am only 15-20 miles from the stations. Turns out I have the smaller ChannelMaster Spartan 3 series (instead of the more popular 7777 pre-amp).

As for the OP, I would think the 4228 would be overkill for just 10 miles out, tho. Plus no way its going to pick up RF 6.

Yes, if you have very long cables you are correct. I agree with you that the CM4228 would be overkill, and in any case as I said would not necessarily solve the multipath problem (if that is what it is). And yes, I fully agree with you on the channel 6 issue. The CM4228 will do a very poor job on VHF-lo, although if the station is close almost anything MIGHT work. .
If it were not for the VHF-lo issue then something like a 42XG would be good, but the VHF-lo means going to a large traditional antenna like the Winegard 7080p

 

[Mike500]

My favorite......

I've tried many many antennas.......

The Winegard Model HD7210P "Ghostkiller" is my favorite.

Winegard --- HD7210P

Winegard HD 7210P Ghost Killer VHF/UHF Yagi Style HDTV Antenna (HD7210P) | HD-7210P [Winegard] | HD7210P HD 7210P HD 7210 HD-7210

I've got a Channel Master Amp on it, and it gets everything. Most of the stations are about 90 degrees apart to the North. It even gets the an ABC affiliate station to the South, not listed on antennaweb.org, because the signal is so strong from that station and overcomes the extremely high front/back ratio of this antenna. I even get the weak ABC affiliate HD station some 45 miles away.

The antenna is very low, without the usual UHF corner refector array, so I can mount it on a standard Dish 300/500 pole.

On analog, it got everything with a fantastic, almost ghost free picture, that is better than my neighbors get on cable or Dish LIL locals.

I am sold on this antenna with amp, when my customers want all the stations in my area.

Antenna installation after feb 17, 2009, will become a lot more difficult, when analog shuts off after that date.

The definitive predictor of possible dropoffs is ghosting in analog. Unfortunately, that will be gone after Feb. 17, 2009. If you eliminate or reduce ghosting, you are also eliminating the possiblity of dropoffs in digital. This will be very problematic for adjusting rotors after Feb. 17, 2009.

Likely, there will be a lot more scammers after Feb. 17, 2009, who will sell antennas. No longer, will it be easy to judge an analog image by just looking at it.

 

[spokybob]

Actually I have a 4221 that was able to receive a low power anlaog ch 6 fairly well. So I am not sure how the 4228 would do. I suspect that if is aligned with the others it woudl do fine. But that narrow beam of the 4228 might have an issue if it is too far from the line of sight.

My 4221 does not pick up either VHF-LO adequately at 21 miles. It does receive analog 8 ok.
Bob ZIP 61231

 

[No Static At All]

Mike 500 is right on the money!!

For close in locations; the Winegard 7210 "Ghost Killer" can't be beat. Forget "any type" of bowtie antenna. They do not handle mutipath well; and close in areas have the highest potential for "extreme" multipath.

The 7210 highs
1. Cheap ($45.00)
2. Great Winegard quality-Built to last
3. Very small
4. Weatherproof balun- 75 ohm connection.
5. Very good VHF-HI/UHF sensitivity for a "combo" antenna.( I get a 23kw VHF 12 @ 65 miles out reliably-NO amp- NO elevation advantage). There are "numerous" full power TV & FM stations less than 4 miles away from me. This thing is "very" selective!!
6. Respectable VHF-LO for it's size.


The Lows
1. Not great for Fringe/Deep fringe areas. ( You should go with separates in these areas anyway).