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View Full Version : What side is the 'front' of the free antenna SnapStream bundled with the USB Gold?


NewestUser
04-27-2007, 04:57 PM
Hi, it's this antenna http://www.snapstream.com/images/store/hdtv/antenna.jpg that I'm wondering about.

what side is the front to face to the transmitter station?
I'm thinking it's like other antennas that look like 'arrows', and the back end of the 'arrow' is really the 'front' end to face at the transmitter, but all this HDTV stuff is new to me, so, I'd like to make sure.

thanks :)

merrypig
04-27-2007, 11:41 PM
I always understood the narrow part of the antenna to be the front that should point towards the source.

Rich A
04-29-2007, 11:44 AM
Yes Merrypig is correct. It is a log-periodic design antenna made primarily for UHF frequencies where it performs best. But if your VHF station is close enough, it will pick that up too. The short end is the front.

NewestUser
04-30-2007, 03:43 AM
this is strange, 'cause it seems to give me a stronger signal facing the other way ... long elements as the front, towards the transmitter.

I'm going to have to check this out again! ...
--------------------
(...goes to test it again...)
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I just tested channel 4 (WNBC-DT) for signal strength, using the short elements as the front, (this one and channel 13 WNET-HD seem to be my weakest) and the signal was much lower (54% and lower on WNBC, and 22% on WNET)
Then, with the longer elements as the front, it went to 74% ~ 84% on WNBC and 65% to 68% on WNET.

It seems the dB value goes higher using the longer elements as front, even with the stations showing 100%, some were less than the full 33.3 dB when using the short elements as the front... (showing 29dB to 27dB).

I also have one of those RadioShack in-line RF amplifiers on this digital antenna, as well, so the signal gets boosted a bit more...
the RF Amp boosts the signal 10dB in the RF range of 5 to 900 MHz.

I'm wondering, if you both try turning the antenna around, and you know the direction of your transmitter towers, just to be sure you face it correctly, will your signal strength go higher?

Rich A
04-30-2007, 11:05 AM
Well my antennas are of course pointed in the correct direction. They are outside my house about 3/4 of the way up a large tower.

Indoor antennas can act weird. If you are dealing with UHF frequencies (at the higher end) the signal could be bouncing off things. A UHF signal can actually find the clearest path by coming in through a window and bouncing around inside the house. This is especially true if you have aluminum siding on the house.

Then there is also mult-path where you don't have a clear path to the station (large buiding, trees, mountain etc) get in the way. In that case by turning the antenna to some other direction you might get the signal being bounced off some other object (like a mountain side or large building) and thus coming in from another direction.

Also if the signal is not UHF but rather VHF it might just come in better off the back of the antenna that has the larger elements. (the lower the frequency the longer the antenna elements are)

Lastly you might be mistaken in your estimation of where the stations are. Did you get your "pointing directions" from antennaweb.org?

I say this because many times the actual physical locations of the transmitting stations are no where near where the main office and studios are.

Trust me ... I've been building my own antennas since I was about 12 years old. (ham radio) I know which end of a log periodic is the front.

cat6man
04-30-2007, 07:29 PM
just to echo....rich is correct and knows which end is up (or front in this case)

if you get stronger signals from the 'back', then either

1) the transmit tower is not where you think it is or
2) you have a strong indoor reflection

by the way, i loaned my antenna (same one) to a neighbor and i am amazed how good a signal that puppy brings in from his attic office....he thought he would need to run cable to an antenna on his chimney and was blown away by the full signal he pulls in which that little pup

Rich A
04-30-2007, 09:23 PM
j

by the way, i loaned my antenna (same one) to a neighbor and i am amazed how good a signal that puppy brings in from his attic office....he thought he would need to run cable to an antenna on his chimney and was blown away by the full signal he pulls in which that little pup

Hmmm those little antennas must make pretty good "loaner" antennas. You know that is exactly what happened to my small indoor antenna. Mine came with the ATI HDTV Wonder tuner. It's called the "Silver Sensor" and I also found it amazing how well it worked. Now my buddy has it on top of his new HDTV and won't give it back. :lol:

NewestUser
05-02-2007, 12:11 AM
thanks, Rich A, for that wealth of information :clapping: :bowdown: I bow down to your knowledge on HDTV and the antennas, but, :rolleyes: as with everything else in life, there's always a first time for things not working as it should :tongue:

I tried, and tried, but can't get the antenna to give a stronger signal facing the smaller elements front. :smile:

for me, the antenna gives a better signal strength with the larger elements facing the transmitter, I went to the antenna org site and was pleased by the info there too... I was able to see the exact direction to face the antenna, and now have a more uniform reception pattern for the two hard to get channels, ... for me ... WNBC and WNET ... with as good a signal as the rest, but, with the antenna facing the exact opposite you suggested it should be :winkwink: most likely, as you said, reflected signals, and being indoors, so I'll have to live with it.

HEY... I wanted to ask, when the TV stations are forced to go ALL Digital, and give up their Analog signals, will the Digital stations go VHF again?

if so, will a standard VHF/UHF/FM outdoor antenna work for HDTV?
I've got one of those still in the box, (from 30 years ago) never used yet, 28 element log-periodic design, antenna.

Rich A
05-02-2007, 08:18 PM
The old antenna should work fine. Most of this "HDTV" antenna stuff is hype. The digital stations are still in the same FCC band plan as the analog. So a standard VHF / UHF antenna should work fine.

Be aware that is a bigger antenna and will have more elements and because of that it will be much more "directive" than the little silver sensor.

Looking at Antennaweb.org if you may find some stations 5 to 10 degrees or more apart. And in some cases because of the high gain and directivity of the antenna, you may find that just a couple degrees difference will mean whether you can get it or not.

The farther away the station is, the more critical the aiming. So you might get one station fine and yet another station just a few degrees away not at all.

Also when you are aiming the antenna try moving it up or down. There is usually a "Sweet Spot" where a particular signal is best received and it won't necessarily be at the highest antenna elevation.

Antennas and radio frequency propagation can be complex. Especially when you get into VHF and UHF line of sight transmissions.

As far as the analog being phased out and all the OTA stations going digital, I don't think you will see much change for the existing digital except that when the stations no longer have to support both an analog and a digital transmitter, they might start upping their digital stations' power. Right now most digital stations are running at a mere fraction of the analog.

I don't know myself, but I would imagine most of the large analog stations might keep the same towers/antennas and just feed them with their new digital transmitters. It's not a VHF / UHF thing. The whole broadcast TV spectrum (both analog and digital) is spread from 56 Mhz up to 900 or something.

I sorta predict that when all the stations are finally switched to digital only that we will probably see a huge positive difference in reception. Like I said, at present the digital stations are running very low power compared to their analog equivalents. For example here the local NBC station is running their analog transmitter at 3,090 Kilowatts ERP. That's over 3 million watts effective radiated power. But their digital transmitter is only running 250 Kilowatts. There's a big difference in receiving a station with a 3 million watt signal versus a 250 thousand watt signal. And I expect when that big 3 million watt transmitter gets moth-balled, that they then will upgrade the remaining digital. I hope so, because it's one of only two stations I have trouble pulling in.

NewestUser
05-03-2007, 12:02 AM
wow, i thought so, (most antennas being good enough for HDTV)
I'm really glad I never tossed this one out :)

I didn't know the digital signal was transmitted with such low wattage,
no wonder I'm having troubles finding the 'sweet spot' of reception ...
Reception here was always good before 9/11 .
OH well, just three more years (2010) when all TV stations MUST switch to all digital , then the signals get stronger,
:dude: I hope :winkwink:

Hey, I remember you said, several posts back, you make your own antennas... do you have a HDTV design, for outdoor, or indoor use, that's easy to construct?

OH, and the antenna in the box, shown in that picture I attached in the post before ... is a 36 element, not the 28 I originally thought it was, so it's going to be even more critical to point .. :lol: ... and easier for the wind to blow down :wink: ... maybe that's why I never put it up 30 years ago.