What will an amplifier do? - White Rock, NM

sweller · 2-Mar-2015, 8:37 PM

After I cut the cable, I pulled up my TV Fool report:
http://www.tvfool.com/?option=com_wr...f1f083f8def533

Through trial and error, I built the folded-dipole antenna in the thumbnail. Don't laugh. It gives me very good results (See attached table).

My question is about the two in the middle: KUPT*

Will an amplifier bring those in?

The question stems from the trial of a cheap Chinese DVR which had a more sensitive tuner than my TV. Before I sent the DVR back, it actually got a lot more than my TV, with the same un-amplified antenna.

I'm sure I did a poor job of describing this, but any input will be greatly appreciated.

timgr · 2-Mar-2015, 9:13 PM

TVFR link doesn't work.

Usually you only need an amplifier to overcome cable losses with a long run of cable. Ideally the amplifier is put right up at the mast, as close to the antenna as possible, so that the strongest signal before the long cable run is amplified. Indeed, amplifiers actually degrade the signal quality slightly, by adding their own amplification noise to the already weak signal (the amplifier's "noise factor"). So you end up with a stronger but lower quality signal.

Probably the cheapest way to get more stations will be to buy a commercially made antenna. Not dissing your home-made antenna - I'm sure it works very well for the expense and effort it required. Once we can see your report, we can comment more.

sweller · 2-Mar-2015, 9:20 PM

Quote:

Originally Posted by timgr

TVFR link doesn't work.
...
Once we can see your report, we can comment more.

Odd That's why I'm a technophobe!

http://www.tvfool.com/?option=com_wr...f1f083f8def533

timgr · 2-Mar-2015, 9:44 PM

Oh! That's quite a nice TVFR. Do have a clear aim to the horizon at compass 190? Very few stations on your report are not at that heading, and almost all of those are impossibly weak. And one KCHF is strong enough that you won't need to aim at it.

A modest antenna like the Antennacraft HBU22 pointed at 190 should pick up all the stations down to KYNM except for K46GY. KUPT is quite strong, and you can probably receive it indoors with some well-aimed rabbit ears. Suspect your dipole isn't tuned that well...

http://www.antennacraft.net/Antennas/AntennasHBU.html
http://www.amazon.com/RCA-Indoor-FM-.../dp/B000HKGK8Y

Lots of signal in the air there.

sweller · 2-Mar-2015, 10:00 PM

When I first saw that report, I was very skeptical because the report for Los Alamos, NM is very, very different. I had to see it in Google Earth to believe it. So yes, I am LOS to Sandia Peak (190). Unfortunately, many of those stations are either not in my native language, or don't fall in line with my spiritual beliefs.

Nothing indoors works because I have a ProPanel (sheet metal) roof.

I won't be surprised if my amateur attempt is poorly tuned, but the table I attached still perplexes me. I can't get my brain wrapped around what's going on between 482 and 488 MHz.

Looking at the Antennacraft HBU22 now. For that small of an investment, the folded dipole wasn't worth my labor. But it *IS* practically bullet proof.

EDIT: Being the tightwad that I am (Hey. I built an antenna!) wouldn't the HBU11 do the job?

timgr · 3-Mar-2015, 12:16 AM

Mmm. Yeah, probably. But you get a lot more antenna for the extra $6. You'll need a balun to go with an Antennacraft antenna - not supplied with it. http://www.amazon.com/WINEGARD-TV-29.../dp/B0029U2XH2

Re your table, KUPT is the lowest power of those that you list, by 6 dB. This is a logarithmic scale, where each 3 dB is a doubling in power. Not really so mysterious.

And I'm not sure where you got different frequencies for 16.1 and 16.3. There's only a single bit stream for each real channel, as I understand it. The virtual channels are multiplexed in that single stream of bits. http://en.wikipedia.org/wiki/Digital_television The broadcast frequency is the analog carrier for the digital stream. The tuner locks on to the carrier - either you get a lock and see TV, or you don't, typically.

GroundUrMast · 3-Mar-2015, 1:20 AM

The last item to skimp on (IMO) is the antenna... It alone does the job of receiving signal... Amplifiers can not and will not add to the performance of any antenna. An amplifier is going to increase the power level of all the signals arriving at it's input... desired and undesired, useful signal and noise or interference. An amplifier is for overcoming loss in cable and splitters.

I'd have no heartburn going up in size... The added gain of an HBU-33 or Winegard HD7694P would ensure that no amplification would be needed even if you opt to split the signal to several more tuners at some point.

Passive antenna gain is not the same as amplifier gain. Passive antenna gain offers more desirable signal while reducing noise and interference from off angles.

timgr · 3-Mar-2015, 12:27 PM

Two brief additional comments, if I may.

More vertical distance between the roof and the antenna may help. Electrical coupling to the roof could be an issue.

Stay far far away from that electric service mast.

sweller · 3-Mar-2015, 3:57 PM

Quote:

Originally Posted by timgr

Stay far far away from that electric service
mast.

Good eye! It's about 60' away.

When I was testing/adjusting/testing the dipole, one of the checks was the height above the ProPanel - in 6" increments (pipe nipples :-) Where it sits is where the signals strengths were best. I'm guessing the ProPanel is acting as a ground plane.

Quote:

Originally Posted by timgr

And I'm not sure where you got different frequencies for 16.1 and 16.3.

My bad. I was referring to the video carrier, ATSC pilot, and audio carrier frequencies.

So I was about to pull the trigger on an HBU11 when I reminded myself -
What I have works. What isn't working is the tuner in the TV. I should be able to find a converter box easily. Unless they're all in the landfills. With one of those I should be able get a better idea how the dipole is performing. Yes?

GroundUrMast · 3-Mar-2015, 11:48 PM

$40 will now buy you a decent HD (1080i) capable set top tuner. http://www.amazon.com/Mediasonic-HW-...eworx+hw150pvr

sweller · 4-Mar-2015, 12:21 AM

Quote:

Originally Posted by GroundUrMast

$40 will now buy you a decent HD (1080i) capable set top tuner. http://www.amazon.com/Mediasonic-HW-...eworx+hw150pvr

Thanks. But that's what I just returned. I really did like it. The tuner was excellent. It just kept losing timer settings which made it pretty useless as a PVR.