The Official AVS Antenna and Related Hardware Topic! - Page 585 - AVS Forum | Home Theater Discussions And Reviews
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post #17521 of 17628 Old 01-23-2019, 01:19 PM
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Originally Posted by rabbit73 View Post
Yup, low-e glass will block TV signals.
Learned that the hard way. Put hurricane windows in our place in FL and had them tinted. It's also the window where my XM antenna sat. Long story short, we stream XM, now.

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post #17522 of 17628 Old 01-23-2019, 02:56 PM
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Sometime ago when I was doing some other tests with an XG91 indoors, I ran a glass attenuation test. The attached spectrum analyzer image shows the difference between channel 40 with no glass and a dual pane low E sliding glass door closed. The signal is very choppy because all I can see from my house is reflections off of mountains. The average glass attenuation was about 9 dB.
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post #17523 of 17628 Old 01-23-2019, 05:39 PM
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Originally Posted by bernieoc View Post
There is a balcony almost perpendicular to source - antenna not allowed - but ch 3 dipole as described (or rabbit ears) could be almost invisible - would need to get signal inside - balcony has glass panels tight shutting doors.
I realize you probably don't want to get into a fight with your landlord right after moving in, but if it comes to that, the law is probably on your side: https://www.fcc.gov/media/over-air-r...n-devices-rule

Essentially, if it's your balcony, and you (and only you) have access to it, they generally can't stop you from putting up a reasonable antenna. But if it's a shared balcony between your apartment and someone else's apartment, they can.

Still, I too would prefer an almost-invisible antenna. There are "flat cable" products to get signals through a doorway that may help.

Also, if a single folded dipole isn't quite enough, you can get an extra 3 dB or so by ganging two identical dipoles together. Perhaps one along the top of the doorway and one along the bottom. Holl-ands could probably help come up with a design that would remain reasonably inconspicuous.
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post #17524 of 17628 Old 01-24-2019, 07:25 PM
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Originally Posted by JHBrandt View Post
I realize you probably don't want to get into a fight with your landlord right after moving in, but if it comes to that, the law is probably on your side: https://www.fcc.gov/media/over-air-r...n-devices-rule

Essentially, if it's your balcony, and you (and only you) have access to it, they generally can't stop you from putting up a reasonable antenna. But if it's a shared balcony between your apartment and someone else's apartment, they can.

Still, I too would prefer an almost-invisible antenna. There are "flat cable" products to get signals through a doorway that may help.

Also, if a single folded dipole isn't quite enough, you can get an extra 3 dB or so by ganging two identical dipoles together. Perhaps one along the top of the doorway and one along the bottom. Holl-ands could probably help come up with a design that would remain reasonably inconspicuous.
My new HOA says antenna may not be visible from the street. So must be below the roof on backside of the house. Is this violation of the FCC OTARD rules?
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post #17525 of 17628 Old 01-24-2019, 07:37 PM
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Originally Posted by tylerSC View Post
My new HOA says antenna may not be visible from the street. So must be below the roof on backside of the house. Is this violation of the FCC OTARD rules?
If your house is free standing and not a condo, it probably is a violation of OTARD. The FCC says your antenna can be as high as 12 ft above the peak of your roof.

OTARD prohibits restrictions that preclude reception of an acceptable quality signal.

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a regulation requiring that antennas be placed in a particular location on a house such as the side or the rear, might be permissible if this placement does not prevent reception of an acceptable quality signal or impose unreasonable expense or delay. For example, if installing an antenna in the rear of the house costs significantly more than installation on the side of the house, then such a requirement would be prohibited. If, however, installation in the rear of the house does not impose unreasonable expense or delay or preclude reception of an acceptable quality signal, then the restriction is permissible and the viewer must comply.
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post #17526 of 17628 Old 01-24-2019, 07:47 PM
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IANAL but I believe it is. The OTARD rule allows antennas to be up to 12 feet above the roofline.

The OTARD rule is not well-known, so I'm not surprised that so many landlords and HOAs have rules that are in violation of it.

Of course, petitioning the FCC for relief is generally a last resort; most folks would prefer to work something out if possible. If an antenna that complies with HOA rules won't work for you, perhaps they'd be OK with one painted sky blue?
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post #17527 of 17628 Old 02-06-2019, 06:59 PM
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Does anyone know what changes were made to the ANT-751E model? The mounting hardware is in the rear again. Thanks

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post #17528 of 17628 Old 02-07-2019, 11:00 AM
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Originally Posted by andy416us View Post
Does anyone know what changes were made to the ANT-751E model? The mounting hardware is in the rear again. Thanks

https://youtu.be/8Ujo4zUSxIE
Don't know but if you need information regarding the differences between the 751 and 7511 which had the image of the 751 on the box, check out this link:

http://forum.tvfool.com/showthread.php?t=16264

It seems that the 7511 was inferior so maybe they went back to the original design assuming your model is a newer one. RCA has also used different letters for their antenna amplifier TVPRAMP1 but the units look to be the same.

I forgot to mention that is a great video for someone installing that model or similar. Very helpful.
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post #17529 of 17628 Old 02-07-2019, 12:12 PM
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At least with the preamps, the original model number was TVPRAMP1R and then TVPRAMP1Z and now currently TVPRAMP1E. The color of the box changed from white blue. That (I think) is about it.
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post #17530 of 17628 Old 02-12-2019, 04:14 PM
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Originally Posted by tylerSC View Post
Disappointing to see Home Depot no longer carries Winegard LNA200 preamp. Only RCA inline amp. With most Radioshacks closed down, you would think they would keep a good antenna preamplifier. At least Lowe's still has the RCA preamp.
Hope Depot is carrying the Winegard on their web site. If someone lives near the store, it could be easily returned if it doesn't work out.

https://www.homedepot.com/p/Winegard...-200/205496018
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post #17531 of 17628 Old 02-28-2019, 12:01 AM
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Dumb question. If the stations you want are close to due north and you have a north facing wall, can you simply slap an antenna like the CM-4228HD against the outside wall?

The only reason I can see for avoiding this is a small lightning danger (at least where I live). I wouldn't think the area behind the antenna would add anything to the signal.
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post #17532 of 17628 Old 02-28-2019, 02:32 PM
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I once tried temporarily hanging a 4-Bay against the Brick Wall on one side of a Garage....nada....had to manually hold it several inches away before it began to get signals....as the Peanut Gallery in the Living Room said HOW IT RIGHT THERE, we want to watch what's on!!!!

Apparently, the close proximity of the Brick Wall was changing the Antenna Performance (Brick has lots of conductive Carbon & Iron in it...and perhaps even some Iron ReBar buried inside). So if it works...Great....but if not, you might want to experiment with mounting it 3-6 inches [or more] away from the Wall.
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post #17533 of 17628 Old 03-02-2019, 06:40 AM
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Originally Posted by holl_ands View Post
I once tried temporarily hanging a 4-Bay against the Brick Wall on one side of a Garage....nada....had to manually hold it several inches away before it began to get signals....as the Peanut Gallery in the Living Room said HOW IT RIGHT THERE, we want to watch what's on!!!!

Apparently, the close proximity of the Brick Wall was changing the Antenna Performance (Brick has lots of conductive Carbon & Iron in it...and perhaps even some Iron ReBar buried inside). So if it works...Great....but if not, you might want to experiment with mounting it 3-6 inches [or more] away from the Wall.
Conversely, at my daughter's house I was having trouble getting reception of her local ABC affiliate. The main antenna (CS2max) plane was at 90-degrees to this station. I combined a 2-bay "Eagle" brand bow-tie antenna with the CS2max and hung it flush against the side of the vinyl-siding of the house. Shazamm!!!!! Great reception!!!!

@Roginator5 , I have no idea how a 4228 will work against your wall or what your wall is built out of, but lots of time getting good reception comes about from experimentation. The wall behind the antenna could actually act as a shield in blocking unwanted signals from hitting the antenna from the rear. Or, it could de-tune the antenna causing reception to be bad/weak. Lots of things like the distance to transmitters, topography between you and and the transmitters, nearby buildings, etc., all come into play. Personally, I'd get a small antenna and a piece of coax long enough to go outside and reach to several points on the north wall. Having sufficient coax cable will let you find a "hot spot" by moving along the length of the wall. It might work...or it might not work. You really won't know until you do a little testing. Best wishes!!! Ed
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post #17534 of 17628 Old 03-03-2019, 03:59 PM
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Antenna idea

Mad experimenter here...

You know how VHF-low dipole antennas are very long? What if instead of a solid copper or aluminum rod, you used two coiled springs around a plastic post? You could adjust the spring lengths by stretching them to notches or bumps on the plastic post. Maybe even have the post marked with channel numbers.

I'd like to see the NEC program figure THAT out.
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post #17535 of 17628 Old 03-03-2019, 04:56 PM
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Quote:
Originally Posted by Roginator5 View Post
Mad experimenter here...

You know how VHF-low dipole antennas are very long? What if instead of a solid copper or aluminum rod, you used two coiled springs around a plastic post? You could adjust the spring lengths by stretching them to notches or bumps on the plastic post. Maybe even have the post marked with channel numbers.

I'd like to see the NEC program figure THAT out.
For HDTV RF 2 the plastic post would need to be very wide, (17.5 / 2 feet).

I know that is about right as I put a VHF Hi-Lo antenna in my attic tied up with string.

Many resources on the internet, it took a little searching to find the length for RF 2.

SHF
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post #17536 of 17628 Old 03-03-2019, 05:53 PM
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Considering how much of a hassle it is to get a VHF signal in some places and that it's much easier for UHF, why don't TV stations just get off VHF and move over to UHF? Just Curious.

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post #17537 of 17628 Old 03-03-2019, 06:17 PM
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Considering how much of a hassle it is to get a VHF signal in some places and that it's much easier for UHF, why don't TV stations just get off VHF and move over to UHF? Just Curious.
Actually many stations, PBS stations were many, made the move in the opposite direction.

WHY? Example:

$72M for KRCB moving from RF 23 to RF 5, a move that that would prevent me from receiving that station.

$12M went to purchase another station (KCSM) which lost Millions and Millions because of a clerical error. KCSM should have received a similar $72M+++ to go off the air. Lawyers have started dueling lawsuits but I have not seen any news lately.

So KRCB now owns a station on Sutro named KPJK. But wait, KRCB is moving to Sutro so I have a chance.

So there will be in 2020 three (3) PBS stations on Sutro.

National PBS must be crying foul heard here all the way from Boston and New York City. No news about that.

Plus all the stations that are moving in frequency get a brand new transmitter for free from the FCC. (~ $19.8B) Wonder why smart phones cost so much?

SHF

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post #17538 of 17628 Old 03-03-2019, 06:41 PM
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Originally Posted by ncsercs View Post
Considering how much of a hassle it is to get a VHF signal in some places and that it's much easier for UHF, why don't TV stations just get off VHF and move over to UHF? Just Curious.
Since the incentive auction, in the bigger markets there's just not enough room up there.

The UHF spectrum allocated for TV stations to use has been steadily shrinking. Back when I was young there were 69 (channel 37 was never used) UHF channels: 14-83!

Channels 70-83 went away first, to make room for cell phones. That wasn't a big deal because the UHF spectrum was very sparely populated back then. Most of us remember the spectrum going from 14-69.

Then with the transition to digital, channels 52-69 went away, to make more room for cell phones. Again it wasn't a big deal for the same reason: there weren't that many UHF stations before the switch to digital.

But digital TV changed the equation. Suddenly UHF became the preferred band. Unfortunately Congress was slow to recognize this, and mandated a sell-off of yet more spectrum; so we're now in the process of clearing out channels 38-51. Once that's done, we'll have only 23 UHF channels (14-36) left; only a third of what we started with. (Also, some cities have a 3-channel gap allocated to police radio, so they're down to only 20 UHF channels )
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post #17539 of 17628 Old 03-03-2019, 08:05 PM
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Originally Posted by ncsercs View Post
Considering how much of a hassle it is to get a VHF signal in some places and that it's much easier for UHF, why don't TV stations just get off VHF and move over to UHF? Just Curious.
With the repack there are no open UHF channels in the major markets. Some stations had to go to VHF.
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post #17540 of 17628 Old 03-04-2019, 09:24 AM
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Originally Posted by Roginator5 View Post
Mad experimenter here...

You know how VHF-low dipole antennas are very long? What if instead of a solid copper or aluminum rod, you used two coiled springs around a plastic post? You could adjust the spring lengths by stretching them to notches or bumps on the plastic post. Maybe even have the post marked with channel numbers.

I'd like to see the NEC program figure THAT out.

I'll give you credit for the idea but that's not how it works. The total length of wire needed for a dipole doesn't change much whether it is straight or coiled. This is where the idea of a "loaded" dipole comes from, typically with coils in the middle of the dipole to shorten its length. A shortened dipole with coils has compromises. The shorter it is, the narrower its bandwidth gets. The shorter it is, the lower the feed impedance. A very short loaded dipole can have a feed impedance of just a few ohms which makes it hard to match. A full sized dipole impedance is 75 ohms. A 2/3 sized loaded dipole impedance is 50 ohms. A 1/2 sized loaded dipole impedance is 25 ohms. The shorter the loaded dipole, the more inefficient it becomes because it intercepts less of the magnetic field it's in generating less signal.

Back to your spring idea.... Stretching a dipole made out of springs won't change the frequency to which it's tuned because the total wire length doesn't change. You will change the impedance and bandwidth though.
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post #17541 of 17628 Old 03-04-2019, 09:55 AM
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Quote:
Originally Posted by ncsercs View Post
Considering how much of a hassle it is to get a VHF signal in some places and that it's much easier for UHF, why don't TV stations just get off VHF and move over to UHF? Just Curious.
I suggest you do some research to determine the lowest RF channel you need to receive after the repack.

https://www.rabbitears.info/market.php

Selecting your market allows you to view the repack channels, look for the stations moving to VHF and find the lowest one you will desire.

RF 5 may be the lowest you need, much smaller size than a RF 2 antenna and buildable.

I am set up for RF 7 and that works just fine. Receiving a RF 5 signal at 36 miles might be doable, I will know in 2020 if my CM4228HD works.

SHF
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post #17542 of 17628 Old 03-04-2019, 05:13 PM
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Looks like the Chicago market. The only post-repack VHF-Lo stations will be WUVI/65 and WOCK/13. WUVI appears not to be on the air, and WOCK seems to be targeting Korean/Asian viewers, so @ncsercs probably doesn't need to worry about either of those stations.

VHF-Hi stations will be WCHU/61, which is Spanish, then WRJK/22. WRJK has Comet so it may be worth trying to receive. It will be on RF 11 after the repack.

So, a UHF/VHF-Hi combo, like a CM-4228HD, would probably be a good choice for most Chicago-area viewers.
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post #17543 of 17628 Old 03-05-2019, 01:35 PM
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PCB Balun in modern [UHF ONLY] Antennas (such as CM4228HD, DB-8e, HDB-8X, 91XG, etc) will attenuate VHF Signals....so to receive Hi-VHF Channels, you would need to MODIFY Antenna, replacing PCB Balun Box with a conventional 300:75-ohm Transformer Balun. Even better, do ONE of the fol. HHH Mods at the same time to improve UHF + Hi-VHF Gain Curve and esp. Hi-VHF SWR:
https://imageevent.com/holl_ands/mul...8hdhhhtsrsyrod [Also Hi-VHF Gain Improvement]
https://imageevent.com/holl_ands/mul...dshorizharness [Just UHF Gain Improvement]
https://imageevent.com/holl_ands/mul...yrefl/cm4228hd [CM4228HD As Shipped]












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post #17544 of 17628 Old 03-20-2019, 09:53 AM
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Antenna Comparisons

Here's something just for fun. For years my UHF antennas have been a pair of XG91s that I have optimized to squeeze every dB out of them. My high VHF antenna has been a homemade a 22 element LPDA on an 18' boom. I used design parameters to max out the size of the LPDA. As back-up antennas on a different tower I had a homemade 37 element LPDA for UHF also designed to max out the size and a custom designed 10 element yagi for high VHF.

Recently I needed to take down the XG91s and the 22 element LPDA and replace them with the smaller 37 element UHF LPDA and the 10 element high VHF yagi. Before I made the switch I captured a number of spectrum analyzer displays and many VHF and UHF stations from both sets of antennas. After the switch I captured another set of analyzer displays. Using Photoshop I combined and labeled the displays.

Attached are the results. The comparison of most interest are the yellow traces (original antennas) and the cyan traces (smaller antennas). Both sets of antennas are in the same position on the tower. The magenta traces are the smaller antennas on the second tower. I had to make "Gain Adjustments" on UHF because the 37 element LPDA used a preamp with 7 dB more gain. The "+5 dB" and the "-2 dB" are referenced to the magenta traces. It's not just one +7 dB adjustment because the coax going to the second tower had 2 dB more loss (+7dB Gain - 2dB = +5 db). Hopefully this is not too confusing.

Modeling for the XG91 shows it to have increasing gain with frequency and the 37 element LPDA to have decreasing gain with frequency. Same goes for the 10 element VHF yagi and the 22 element element VHF LPDA.

I don't understand why the 22 element LPDA is so much better than the 10 element yagi. I have no reason to think that the 10 element yagi is not working. On UHF the performance of each antenna is generally as expected. The XG91 gain is lowest at the low frequency end. The 37 element LPDA is as good or better then the pair of XG91s on channel 15. The XG91s really shine above channel 35 but that doesn't mean much after the repack.

I'm hoping that after the repack the XG91s will be redesigned for the repacked UHF band.
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post #17545 of 17628 Old 03-20-2019, 02:02 PM
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If I understand your plots the VHF yagi performed about the same as the LPA when the yagi was mounted on the lower tower. I would suspect something happened when it was moved.
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post #17546 of 17628 Old 04-17-2019, 08:02 AM
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Which would you pick?

My TVFool:

http://www.tvfool.com/?option=com_wr...90380db6808f9c


I currently have an antenna similar to this one with the RCA Pre-amp:
It barely pulls in 43.1 which is at the edge of the green zone. I'm not impressed with it's strength

https://store.antennasdirect.com/Cle...V-Antenna.html


I'm attached to a J Pole outside. So I'm looking to upgrade. I thought about rotating this one north, and getting a new antenna and pointing it west.

I think traditional Yagi is the way to go here. I was looking at these two:


GE Yagi


RCA mini Yagi

Or do you have a better recommendation?

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post #17547 of 17628 Old 04-17-2019, 09:23 AM
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Quote:
Originally Posted by SFischer1 View Post
You should study Larry's "Repack channel listings". It is too close to 2020 when the repack will happen for anyone to make any antenna choice based on today.

Note: You cannot combine two antennas except for a VHF only one and a UHF only one.

https://larrykenney.com/sfonair3.html

SHF
I understand repack is just a changing of channels to free up unused space and reallocate for other purposes including ATSC 3.0 transmissions. Is this correct? So why would antenna choice matter here? As I understand it, the current locations for antennas is not going to change. And only 1 channel uses VHF (8.1/8.2) Plus, none of my planned stations is listed for the ATSC 3.0 rollout (Harrisburg/York PA area). So I'm pretty sure I'm not affected.

That said, there's no reason you can't combine multiple directional antennas via a splitter/combiner that I'm aware of. Yes I realize I'll lose 3dB on each.

Please feel free to correct me if I'm wrong.

Speaker design is rather an art. There is no such thing as the perfect painting. Likewise there is no such thing as a perfect speaker. It's part science and part personal preference.

Last edited by DigitalGriffin; 04-17-2019 at 09:58 AM.
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post #17548 of 17628 Old 04-17-2019, 10:16 AM
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Originally Posted by DigitalGriffin View Post
I understand repack is just a changing of channels to free up unused space and reallocate for other purposes. Is this correct? So why would antenna choice matter here? As I understand it, the current locations for antennas is not going to change. And only 1 channel uses VHF (8.1/8.2) Plus, none of my planned stations is listed for the ATSC 3.0 rollout.

That said, there's no reason you can't combine multiple directional antennas via a splitter/combiner that I'm aware of. Yes I realize I'll lose 3dB on each.

Please feel free to correct me if I'm wrong.
Combining two VHF antenna with a combiner is a great method of producing multipath, the result may be for some channels NO Picture and NO Sound.

Exact ally the same for two UHF antennas.

The results of combining any two antennas is unpredictable but usually very bad.

Some stations moved from UHF to VHF, usually PBS.

For a quick way to check the new channels for your market, check your market(s) here:

https://www.rabbitears.info/market.php

Look at the physical channels, if a number 14 or above changes to 13 or below, the station has received lots of Millions of dollars.

Another list to check is:

https://www.rabbitears.info/repackchannels.php

As to when the repack will occur for a market, this is a hard way do find out:

https://www.rabbitears.info/phasemap.php

Hopefully some one else can provide an easier method of finding your repack date(s).

My solution is to use separate tuners for antennas.

I have six tuners on my main outside antenna.

The two additional indoor antennas each have separate tuners, one tuner has an input switch so it can use both my main antenna and it's very own indoor antenna.

-----------------------------------------

ATSC 3.0 uses the exact same antennas as ATSC 1.0 - 2.0.

The problem is that during the transition stations may agree to combine their signals on one transmitter thus what channel you need to receive may change.

Combining stations on Lighthouse stations using ATSC 1.0 - 2.0 may exist for many years and ATSC 3.0 agreements may change.

------------------------------------------

Sorry about the reply I deleted, I am busy getting my automatic scheduling and capture program set up for a station that changed ownership with new programming I am interested in at midnight. I did not realize your post was here.

I know somewhere there is a good method to find your repack dates, I don't have time right. now

SHF
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post #17549 of 17628 Old 04-17-2019, 10:42 AM
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Quote:
Originally Posted by DigitalGriffin View Post

That said, there's no reason you can't combine multiple directional antennas via a splitter/combiner that I'm aware of. Yes I realize I'll lose 3dB on each.

Please feel free to correct me if I'm wrong.
You can combine a VHF antenna with a UHF antenna using a special UVSJ combiner.

You can combine two identical antennas pointing in the same direction using a phasing harness to increase signal strength.

However, it is very difficult to combine antennas using a common splitter/combiner. You will receive some stations at one antenna that are slightly out of phase with the other antenna (even if they are pointing in opposite directions). The result when you combine them is that the signals can greatly decrease or cancel each other out completely. I am working with someone on a different forum who is experiencing that problem right now.

You can however combine antennas using a specially designed selective combiner that receives a specific channel on one antenna and another group of channels on another antenna. You need to spend a little time and identify exactly which channels you want to receive with each antenna. I think you can specify up to four inputs.

For example, all of my stations are located to my southeast except for one that is located north of me (channel 31). I use a selective combiner that is tuned for channel 31 on one input and the other channels on the other input. The only place I know of that is still making them is in Slovakia. The one I ordered is of very good quality and the price was reasonable. Since my station on 31 is moving to 16 in the repack, I will have to replace it soon. You can order them from Jan Jenca in Slovakia: http://www.antenne-komponenty.eu/eng...zlucovace.html
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Last edited by richart; 04-17-2019 at 10:46 AM.
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post #17550 of 17628 Old 04-17-2019, 10:52 AM
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All good information, without further analysis I cannot say if it applies to the OP. Web page is dated 2009.

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