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Discussion Starter · #1 · (Edited)
and by cup, I mean house.

My TV Fool report.

I currently have my main antenna, the Terrestrial Digital DB8 Multi-Directional 'Bowtie' UHF DTV Antenna, pointed at 354 degrees. I can get all Boston stations, which are around 40 miles away, without any issues. The location of the antenna is in the attic, but I cannot rotate the antenna toward the Providence stations (due to rafters being in the way), which are roughly 12 miles away at 318 degrees. So, I have an issue with getting these stations clearly, on a consistent basis.

The only stations that I want from Providence are 6.1, 10.1, and 12.1.

So, my solution was to order the AmazonBasics Ultra-Thin Indoor HDTV Antenna - 35 Mile Range, coupled with my DB8, and ideally get all the Boston stations like I normally do along with those 3 stations from Providence.

Any ideas on my best approach on this?
 

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Probably doomed to failure, especially using a common splitter, but give it a try.

You'd probably be far better off starting from scratch with a DB4e. It has a wide enough beam width on UHF to pick up the UHF broadcasts without rotating back and forth and usually picks up high-VHF at 30-50° off to the sides of straight ahead. If you need it, a simple VHF attachment can be added for your VHF 12 & 13 signals from Providence.
 

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and by cup, I mean house.

My TV Fool report.

I currently have my main antenna, the Terrestrial Digital DB8 Multi-Directional 'Bowtie' UHF DTV Antenna, pointed at 354 degrees. I can get all Boston stations, which are around 40 miles away, without any issues. The location of the antenna is in the attic, but I cannot rotate the antenna toward the Providence stations (due to rafters being in the way), which are roughly 12 miles away at 318 degrees. So, I have an issue with getting these stations clearly, on a consistent basis.

The only stations that I want from Providence are 6.1, 10.1, and 12.1.

So, my solution was to order the AmazonBasics Ultra-Thin Indoor HDTV Antenna - 35 Mile Range, coupled with my DB8, and ideally get all the Boston stations like I normally do along with those 3 stations from Providence.

Any ideas on my best approach on this?

A second antenna and an A/B switch.
 

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Are you going to be recording anything while away that would require a change of direction from Boston to Providence? If not go with an A/B switch, simple and will do what you want. I used to have one from Radio Shack that was heavy duty and worked very nicely.
 

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Maybe a ganged antenna would help you.

Try this link for more info:

http://www.hdtvprimer.com/

The html is really primitive. You cannot navigate it unless you start at the top.

Click down into:

->http://www.hdtvprimer.com/ISSUES/erecting_antenna.html

-->http://www.hdtvprimer.com/ANTENNAS/ganging.html

and you want The Two-Antenna Trick (outdoor version)
under Example 2: Chantilly, Virginia 20151

In that example you will see two 4-bay antennas ganged, spaced apart, and phased such that they provide two lobes, one strong and one weaker, that you can aim at two locations.

Read this to get the background theory of operation and how you could apply it on indoor antennas:

--->http://www.hdtvprimer.com/ANTENNAS/silver.html#TAT

plus if you have room to install them side by side you might want to read about ganging two channel master 8 bay and see if that possibility would also apply to your DB8

--->http://www.hdtvprimer.com/ANTENNAS/16bay.html

I have the channel master 8 bay that the author used in the 16 bay example and the man who recommended that antenna to me did so because its response extends down into the VHF band. Not sure but suspect that characteristic might exist in most such 8 bay UHF if it is a property of the interconnect between 4 bay branches. Anyway I can verify that the channel master does get substantial VHF signal.

Does your DB8 receive VHF too? If you have the room you might be able to try ganging another DB8 in a side-by-side and take advantage of the lobing you can get by adjusting the spacing and phase.

If none of these options makes sense in your situation (or you just do not feel like investing that much effort) there is background on using a combiner like you asked about at

http://www.hdtvprimer.com/ANTENNAS/merging.html

Hope that helps.:)
 

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I analyzed the "Two Antenna Trick" with a pair of CM4221HD 4-Bays, with one of the Baluns with the Twinlead connection REVERSED from the other, so that they were OUT-OF-PHASE and hence formed a NULL in the Forward direction and a pair of Beams
http://imageevent.com/holl_ands/sta...duhfantennas/hstacked2xcm4221hdhackednullbeam
These result are probably close for other wide beamwidth 4-Bay Antennas, but would need to be rerun for Antennas with significantly narrower Beamwidth.

Note that the Angle between the Null and the Beam on either side VARIES with Frequency (Double the Angle on the X-Axis for the Beam-to-Beam Angle):
http://photos.imageevent.com/holl_ands/stacked/horizontallystackeduhfantennas/hstacked2xcm4221hdhackednullbeam//H-Stk_CM4221HD_TL%20Null-Beam-Degrees%20vs%20Stk-Distance.jpg

So you would be better trying a wide beamwidth Antenna, such as a SINGLE 4-Bay, as recommended above....yes it has about 3 dB lower Gain than 8-Bay, but it avoids the 4+ dB LOSS in the RF Combiner used with TWO Antennas.
 

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I analyzed the "Two Antenna Trick" with a pair of CM4221HD 4-Bays, with one of the Baluns with the Twinlead connection REVERSED from the other, so that they were OUT-OF-PHASE and hence formed a NULL in the Forward direction and a pair of Beams
http://imageevent.com/holl_ands/sta...duhfantennas/hstacked2xcm4221hdhackednullbeam
These result are probably close for other wide beamwidth 4-Bay Antennas, but would need to be rerun for Antennas with significantly narrower Beamwidth.

Note that the Angle between the Null and the Beam on either side VARIES with Frequency (Double the Angle on the X-Axis for the Beam-to-Beam Angle):
http://photos.imageevent.com/holl_a...21HD_TL Null-Beam-Degrees vs Stk-Distance.jpg

So you would be better trying a wide beamwidth Antenna, such as a SINGLE 4-Bay, as recommended above....yes it has about 3 dB lower Gain than 8-Bay, but it avoids the 4+ dB LOSS in the RF Combiner used with TWO Antennas.
Deferring to someone who probably knows more about this than I do.:)
 

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...I currently have my main antenna, the Terrestrial Digital DB8 Multi-Directional 'Bowtie' UHF DTV Antenna, pointed at 354 degrees. I can get all Boston stations, which are around 40 miles away, without any issues. The location of the antenna is in the attic, but I cannot rotate the antenna toward the Providence stations (due to rafters being in the way), which are roughly 12 miles away at 318 degrees. So, I have an issue with getting these stations clearly, on a consistent basis.

The only stations that I want from Providence are 6.1, 10.1, and 12.1.
Note that the Angle between the Null and the Beam on either side VARIES with Frequency (Double the Angle on the X-Axis for the Beam-to-Beam Angle)...So you would be better trying a wide beamwidth Antenna, such as a SINGLE 4-Bay, as recommended above....yes it has about 3 dB lower Gain than 8-Bay, but it avoids the 4+ dB LOSS in the RF Combiner used with TWO Antennas.
Looking at this again I wonder if the 'Frederick' simulation with an on-axis null applies to the OP.

The scenario is two directions that are substantially different in distance from each other, not equidistant. Besides, the OP indicated inability to rotate the antenna away from Boston and toward Providence. Also, the simulation used a wide separation of 40" to 120" that is clearly not indicated by the application. 30" would be more appropriate in this example.

Trying this again... assume two DB4 antennae.

354-318=36 degree separation, with Boston more than three times as far away and -30dB compared to Providence, and approaching the fringe of reception so the example 2 -- Chantilly -- I suggested (with the on-axis lobe active) is the applicable one, not example 1 -- Frederick. Now the OP can aim the on-axis lobe toward Boston and achieve essentially the same gain he is currently getting for his fringe-ish Boston reception, with little to no deterioration in performance for these channels.

The appropriate separation is 36" for this in-phase connection. Now an additional frequency-dependent lobe extends between 27 and 41 degrees off-axis with a net gain of +3db-5db (for off-axis loss, estimated from the channelmaster table)=-2dB compared to a single 4-bay pointed in that direction.

Even accounting for the frequency-dependent off-axis variation in the second lobe I am not seeing an issue. Providence is 30dB stronger than Boston anyway.

OP additionally gains multipath rejection from the nulls that are created. Wondering if the multipath is the real issue with his existing antenna.

OK I am not RF expert but according to what I see in the charts I am not perceiving a huge problem with this suggested implementation.

What about the wide beam antenna? OP loses 3dB immediately from the Boston stations with a 4-bay and additional loss from off-axis reception for Providence. Will that really work any better?

Not challenging anyone, just asking, so please take my comment in the spirit offered.:)
 

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Discussion Starter · #12 ·
Appreciate the help everyone.

I went with a combiner, considering it's the cheapest solution of the bunch. We used it last night, and didn't have any ghosting or overlapping issues. At least not yet...

If that doesn't work, I'll proceed with the other suggestions.

Thanks again.
 
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