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-   -   Fracarro antennas & AbilityHDTV ULNA? (http://forum.tvfool.com/showthread.php?t=2915)

Dave Loudin 6-Jan-2012 2:34 AM

I dare say you will not find any definitive information regarding multipath performance. You'd have to do an A/B comparison at the same site to get anything concrete, since every location is different.

be236 7-Jan-2012 1:30 AM

Quote:

Originally Posted by GroundUrMast (Post 18947)

It's not a direct comparison, but my recent purchase of a Winegard HD8800 has been disappointing. I had to run to the hardware store to replace missing machine screws which could and should have been packaged better... and had simply fallen out of the box during shipping. There is no anodizing or other coating on the aluminum parts, so corrosion will be a problem a bit sooner. (To be fair, the Antennacraft is not anodized either.) The electrical performance of the HD8800 has been significantly less than lesser antennas, including a crudely built DIY 4-bay w/reflector. At present, modification of the combining harness is a 'back-burner' project (after some reading over at the Antenna Development section of digitalhome.ca).

I have to agree! I just bought HD-8800 and compared with my home-made 4-bay M4 and SBGH, it has similar performance (eg, not any better).

I'm a little disappointed, since I was hoping it would have higher gain to pull in my low-UHF channels (RF 17 to 32).

Alas, looks like I'll have to try and order a CM 3023 instead Yagi (trying to avoid 91XG since many reports says it's not good at low-UHF)... but... who knows, it may work in my situation/location...

otadtvman 7-Jan-2012 4:08 AM

Quote:

Originally Posted by be236 (Post 18999)
Alas, looks like I'll have to try and order a CM 3023 ... (trying to avoid 91XG since many reports says it's not good at low-UHF)

Quote:

Originally Posted by tylerSC
Unfortunately, all CM antennas are now made in China ...

91XG: 11.8 dBi (~9.65 dBd) @ 470 Hz, which is not bad considering that the new DB4e is supposed to be designed for 14-51 has a "Boresight gain" of 11.68 dBi (~ 9.53 dBd) @ 470 Hz - not any better than the 91XG.

The Fracarro sigma 6 & 9HD have respectable gain:
  • Sigma 9HD provides 14 dBi (~11.85 dBd) @ 480 Hz
  • Sigma 6HD provides 13 dBi (~10.85 dBd) @ 480 Hz
and less wind-load due to their smaller size.

Dave Loudin 7-Jan-2012 4:56 AM

Boresight gain is the same gain as quoted by others. What Antennas Direct is emphasizing is where in azimuth that gain exists: right along the axis of the boom of a Yagi or perpendicular to the plane of the elements of a bowtie array.

otadtvman 7-Jan-2012 3:11 PM

Precise aiming required?
 
Thanks for the info Dave.

AD is the 1st I've seen to use this term. Is AD saying that precise aiming is required with the new DB4e to acheive the max gain that's advertised?

MisterMe 7-Jan-2012 5:25 PM

Quote:

Originally Posted by otadtvman (Post 19022)
Thanks for the info Dave.

AD is the 1st I've seen to use this term. Is AD saying that precise aiming is required with the new DB4e to acheive the max gain that's advertised?

This is true of all antennas. However, maximum gain is not always necessary. You may receive sufficient signal at 95% maximum, 80% maximum, or less. If you live in an area where the transmitters are in different directions, then it may be possible to find an optimal direction where the antenna receives most of your channels without rotation.

otadtvman 29-Jan-2012 9:49 PM

91XG (14-69) vs. 4-Bay w/Reflector (7 or 14-51)?
 
Hi GroundUrMast,

Since you own both the 91XG and a DIY 4-bay w/reflector, I would appreciate if you could share you experience with them.

Quote:

Originally Posted by GroundUrMast (Post 14647)
One of our on going problems here in the US is that many existing antenna designs are optimized for the pre-2009 UHF spectrum that included channels 52 to 69 (698 MHz to 806 MHz). This results in antennas that have less gain than would be possible if they were optimized to cover a narrower range of frequencies. (As I say this, I get frustrated at the FCC's decision to sell spectrum out from under the tax paying public. I long for the days when UHF antenna design needed to account for more bandwidth.)

http://en.wikipedia.org/wiki/Televis...el_frequencies

Quote:

Originally Posted by otadtvman (Post 18774)
I too have been asking when we would see 7-51 VHF-hi/UHF or 14-51 UHF antennas since the begining of the DTV transition.

Quote:

Originally Posted by GroundUrMast (Post 18936)
My personal experience has been that for deep fringe applications, the combination of an XG-91 and a Y**713 is the pinnacle of consumer grade antennas. Those antennas have narrow forward beam patterns compared to panel and LPDA designs.

Quote:

Originally Posted by GroundUrMast (Post 18947)
... my recent purchase of a Winegard HD8800 has been disappointing. I had to run to the hardware store to replace missing machine screws which could and should have been packaged better... and had simply fallen out of the box during shipping. There is no anodizing or other coating on the aluminum parts, so corrosion will be a problem a bit sooner. (To be fair, the Antennacraft is not anodized either.) The electrical performance of the HD8800 has been significantly less than lesser antennas, including a crudely built DIY 4-bay w/reflector.

Quote:

Originally Posted by be236 (Post 18999)
I have to agree! I just bought HD-8800 and compared with my home-made 4-bay M4 and SBGH, it has similar performance (eg, not any better).

I'm a little disappointed, since I was hoping it would have higher gain to pull in my low-UHF channels (RF 17 to 32).

Alas, looks like I'll have to try and order a CM 3023 instead Yagi (trying to avoid 91XG since many reports says it's not good at low-UHF)... but... who knows, it may work in my situation/location...

Which of these two choices is best suited for our location?
  • M4 complete kit w/curved 1x2" welded-wire reflector (7-51 0ne-antenna solution)
  • AD 91XG + YA-1713 (7-69 stacked-antenna solution)

Thank you

GroundUrMast 15-Feb-2012 5:20 AM

Thanks for your patience
 
The M4 is a very good antenna, when compared to other 4-bay panel style designs. However, it's not surprising that a 4-bay panel antenna would have less gain and or directivity than of a long Yagi style like the 91XG or 10 element H-VHF products from Winegard and Antennacraft.

When you look at the performance graphs of the M4 (image 2 & 3 at http://m4antenna.eastmasonvilleweath...Data/Data.html) neither the UHF or H-VHF performance matches the lager commercial antennas. In particular, the H-VHF performance is modest at best... better than most other 4-bay panel products yes, but not at all comparable to an antenna designed for the H-VHF band.

Also, looking at the polar plots for the M4... I'm quite confident that the directivity of the long Yagi style antennas will offer better multipath rejection than 4 or 8-bay panel antenna designs.

Bottom line: I vote for the 91XG + 10 element H-VHF (with a slight bias toward the Antennacraft product given it's traditional 300Ω feed point).

As an aside, is there any reasonable way to obtain right of way to mount an antenna on the other side of the offending trees? Besides a long coax run, there are theoretical ways to use WiFi or wired Ethernet to back haul one or more DTV signals...

again,

Thanks for your patience

be236 24-Apr-2012 4:10 PM

M4 vs HD8800
 
Well, my target channels are about 107miles away.

I built an M4 awhile back and compared it to an HD-8800 and they had about similar performance. My RF channels 20 and 22 would get a picture signal every once in a while at that distance.. say 20% uptime.

Then I made another M4, attached it to the first one, to make an M8 (8-bay panel design), and for low UHF, I can now pick up RF 20 and 22 (OMNI and CHAN) about 80-90% of the time... of course the picture goes away during daytime or when it's hot (but I'm at work so I dont miss much), but I can watch these channels most of the time when I get home.

The M8 was designed for low UHF so I can understand why it can't seem to pick high UHF (RF 26 and higher), so in this case I am considering if getting a 91XG will get me these upper channels (and still get RF 20 and 22)... hmm..


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