Analog Transmit Watts power vs. DTV watts power - question

staticMHZ · 11-12-2008, 02:57 PM

First of all, glad I found this forum, I've been an over the air television viewer for years

Now, I live in a first floor apartment, and I have the magnavox DTV box, and, after several antenna experiments, with amplified rabbit ears, to regular rabbit ears, I've had lots of problems with reception.

With analog, I was able to get alot of channels even though they were snowy, with digital, I can only get 1 channel and when it rains out the signal knocks out.

According to antennaweb I live approximately 38 miles from the major city (Boston, Mass), where all the local TV stations are. (Although there transmitters are located in Needham).

Looking at Wikipedia, I've noticed that on most stations, their analog towers had a very very high transmit power (mostly up in the 2,000 kw's), while their digital channels were low low low in the hundred's.

Once the full shutoff happens, and the analog channels are gone, will they start broadcasting the digital channels at FULL power?

So that us folks out in the middle of nowhere with no option for an outdoor aerial can pick up more stations? This seems reasonable, as digital will be the only format.

Aaron62 · 11-12-2008, 03:30 PM

Hi there Static,
Not sure how much help I'll be, but, if you get a chance, what kind of powered antenna was it? Was it just powered rabbit ears, or did the antenna also have a circular type shape to it with rabbit ears?

It definitely sounds like you're going to need to experiment with antenna and antenna placement. Does your magnavox converter box have an input for a smart antenna?

staticMHZ · 11-12-2008, 03:45 PM

No, no smart antenna just regular RF. And just those regular rabbit ears with the gain knobs and the AC adapters that you plug in. Dipoles for VHF, and the loop for UHF.

I put some rabbit ears out on the 2nd floor balcony and I did a scan and found 4 channels. (all VHF). To my suprise, a regular non-amplified pair of rabbit ears works far better then those amplified ones.

I get 0 UHF channels. On a very rare occasion I am able to get alot of different channels but they get all pixelated and dissapear. I can only guess this is because of the low low watts power most stations are transmitting at.

I think the main problem is because I live on the first floor, and because of my range from the towers.

What I would really like to know is if they are going to increase the power once analog is turned off. Maybe I should contact WHDH 7. Analog seems to have a very better range then digital does.

I'm sorry if this is unclear, below is mainly what I'm trying to explain.

WHDH 7 (boston)

Transmitter Power 316 kW (analog)
948 kW (digital)

Height 306 m (analog)
288 m (digital)

WCVB 5 (boston

Transmitter Power 61.7 kW (analog)
625 kW (digital)
Height 353 m (analog)
390 m (digital)

WFXT 25 FOX (boston)

Transmitter Power 1950 kW (analog)
(digital) 78 kW current, 780 kW planned after 2009 (digital)

So I guess WFXT is going to INCREASE their transmitting power once analog goes dark.

Hopefully the others will do the same.

staticMHZ · 11-12-2008, 03:50 PM

It appears there are many more people complaining about the low transmit power. WFXT on wikipedia says the following

Many Boston-area residents have complained about poor reception of WFXT-DT as compared to other major local broadcasters. This is due to the transmitter currently operating under a reduced power output reported to be 78kW. However, a July 2007 FCC filing shows that WFXT-DT is currently licensed to transmit up to 154kW, but it is unclear if the full licensed power is being used. Bill Holbrook, Chief Engineer for WFXT, has stated publicly that the full power broadcast may not be reached until August 2009, when construction of a new antenna and transmitter will be complete (note: "new antenna" may very likely refer to the actual transmitter on the current tower, with a DT transmitter replacing the current analog transmitter after the DTV transition.) It is unclear whether there will be incremental improvements between the DTV transition, which will free up space higher on the current tower that is currently used by the analog transmitter, and the full power broadcasts scheduled for August 2009.

It is also alleged that one reason for the current low power broadcasts may be due to requirements to avoid interference with WTIC, another FOX affiliate broadcasting digital programming on the same channel (31) from less than 100 miles away[6]. However, this allegation suggests that WFXT would have to switch digital programming from channel 31 to channel 25 after the DTV transition to resolve this interference, which contradicts other available information.

Jay · 11-12-2008, 07:48 PM

Quote:

Originally Posted by staticstem

No, no smart antenna just regular RF. And just those regular rabbit ears with the gain knobs and the AC adapters that you plug in. Dipoles for VHF, and the loop for UHF.

I put some rabbit ears out on the 2nd floor balcony and I did a scan and found 4 channels. (all VHF). To my suprise, a regular non-amplified pair of rabbit ears works far better then those amplified ones.

I get 0 UHF channels. On a very rare occasion I am able to get alot of different channels but they get all pixelated and dissapear. I can only guess this is because of the low low watts power most stations are transmitting at.

I think the main problem is because I live on the first floor, and because of my range from the towers.

What I would really like to know is if they are going to increase the power once analog is turned off. Maybe I should contact WHDH 7. Analog seems to have a very better range then digital does.

I'm sorry if this is unclear, below is mainly what I'm trying to explain.

WHDH 7 (boston)

Transmitter Power 316 kW (analog)
948 kW (digital)

Height 306 m (analog)
288 m (digital)

WCVB 5 (boston

Transmitter Power 61.7 kW (analog)
625 kW (digital)
Height 353 m (analog)
390 m (digital)

WFXT 25 FOX (boston)

Transmitter Power 1950 kW (analog)
(digital) 78 kW current, 780 kW planned after 2009 (digital)

So I guess WFXT is going to INCREASE their transmitting power once analog goes dark.

Hopefully the others will do the same.

Great information Static and welcome to the site!

Many of the local stations here in AZ that were broadcasting analog signals on VHF frequencies, are now broadcasting under UHF frequencies with digital signals. Rabbit Ear (Dipole) antennas are great for VHF reception, but not so good for UHF digital frequencies.

Also, rabbit Ear antennas manufactured with a loop are supposed to work well with VHF and UHF channels, but only do so if you are located within a close proximity of broadcast towers.

You may want to purchase a good uhf/vhf antenna from a store with a good return policy and see if it offers any improvement. My best guess is the UHF frequencies you are having a problem receiving. Hope this helps.

HTNut · 11-12-2008, 08:36 PM

I'm a big fan of panel antennas like the DB2 or DB4 made by Antennas Direct. Just wanted to throw that out there just in case you were thinking about getting a Yagi antenna. A panel antenna has much less of a chance to pick up distortion, which I think that you are experiencing. You can add a low cost preamp to it which would probably do the trick if you are still missing a couple of channels.

Wanted to give forum member Cowboy a shoutout since he's been working on some reviews for antennas at: http://www.dtvusaforum.com/dtv-recep...a-reviews.html


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