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Antenna preamps?

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November 25, 2004 11:49:47 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

I'm considering purchasing a new antenna preamp. The principal reason
is that I cannot receive the digital transmission of a local PBS
station. Their analog version comes in fine. I've checked with the
station and they claim to be operating full time at full power. There
are no obstructions such as hills blocking the line of sight between
the the transmitter and my antenna.

I'm currently using a 20 year old RS preamp (up to 25 db gain).
The antenna is a new Radio Shack 120" VHF/UHF/FM.
The cable is new RG-6 and the total run is about 30 feet from antenna
to TV. I'm using a rotator and am sure that I have good alignment.
The antenna is in the attic. I realize that I will probably get better
reception by moving it outside on top of the roof, but don't want to
do that (ugly). I do know that its not a matter of sheathing material
because its the same as for the stations that do come in well (1"
boards covered with ashphalt shingles). One station coming in well is
looking through aluminum siding.
The tv is a Sony KD-30SX955.

Other stations come in fine, both in analog and digital. Some of these
stations are transmitting a weaker signal and are further away, but
from different directions.

Is a higher gain preamp likely to improve the situation?

What Radio Shack offers now claims "up to 30 db gain". I don't want to
buy another preamp and take the time to install it if it isn't likely
to improve anything. I understand that it is possible to overdrive the
front end of the tv.

Other than that, I'm quite impressed with the quality of the picture,
especially HD. Even analog transmissions are far superior to what I
was getting before on a 16 year old Akai (Mitsubishi).

Bob

More about : antenna preamps

Anonymous
November 25, 2004 3:17:30 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

"Bob" <rharvey422@att.net> wrote in message news:5cf410c1.0411250849.23268787@posting.google.com...
> I'm considering purchasing a new antenna preamp. The principal reason
> is that I cannot receive the digital transmission of a local PBS
> station. Their analog version comes in fine. I've checked with the
> station and they claim to be operating full time at full power. There
> are no obstructions such as hills blocking the line of sight between
> the the transmitter and my antenna.
>
> I'm currently using a 20 year old RS preamp (up to 25 db gain).
> The antenna is a new Radio Shack 120" VHF/UHF/FM.
> The cable is new RG-6 and the total run is about 30 feet from antenna
> to TV. I'm using a rotator and am sure that I have good alignment.
> The antenna is in the attic. I realize that I will probably get better
> reception by moving it outside on top of the roof, but don't want to
> do that (ugly). I do know that its not a matter of sheathing material
> because its the same as for the stations that do come in well (1"
> boards covered with ashphalt shingles). One station coming in well is
> looking through aluminum siding.
> The tv is a Sony KD-30SX955.
>
> Other stations come in fine, both in analog and digital. Some of these
> stations are transmitting a weaker signal and are further away, but
> from different directions.
>
> Is a higher gain preamp likely to improve the situation?

No, not if your existing preamp is working the way it should.
But maybe the gain is rolling off with frequency or something.
Are you receiving channels both above and below the PBS ok?

What is the channel number? Maybe you'd be better off adding
a better UHF antenna. The fm-vhf-uhf antennas don't really
have a lot of gain at uhf. A uhf antenna is small and fairly
cheap. Try plugging in a uhf antenna only. Then add an amplifier.
Then combine it with your other amplified antenna.

>
> What Radio Shack offers now claims "up to 30 db gain". I don't want to
> buy another preamp and take the time to install it if it isn't likely
> to improve anything. I understand that it is possible to overdrive the
> front end of the tv.

A low noise amplifier with 25 dB gain, if it's working right, is
good enough for your situation.

Don
November 25, 2004 7:23:39 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

> No, not if your existing preamp is working the way it should.
> But maybe the gain is rolling off with frequency or something.
> Are you receiving channels both above and below the PBS ok?
> What is the channel number?
Its 57.1 and 57.2. Channels 56.1 and 59.1 are coming in fine.

Thanks, Any recommendations on a good UHF antenna?

Bob
Related resources
Anonymous
November 26, 2004 3:11:59 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

On 25 Nov 2004 16:23:39 -0800, rharvey422@att.net (Bob) wrote:

>> No, not if your existing preamp is working the way it should.
>> But maybe the gain is rolling off with frequency or something.
>> Are you receiving channels both above and below the PBS ok?
>> What is the channel number?
>Its 57.1 and 57.2. Channels 56.1 and 59.1 are coming in fine.
>
>Thanks, Any recommendations on a good UHF antenna?
>
>Bob

Winegard PR04400 or a Channel Master 4 Bow Tie works very well.
Winegard is lots lighter in weight but works really well. Jerrold is
another good brand but maybe hard to find.

I would ask you to check for you PBS digital station on another
channel. Seems with the digital signal they can select what channel
they want on your digital channel readout. For instance my off-line
PBS station is like channel 13 analog. My Dish 811 receiver shows
them on channel 30.1 and 30.2.

I switch to my Sony HD set and use its channel selector with the same
off-air antenna feed. Now that PBS digital signal comes in on channel
13.1 and 13.2 just above their analog channel. Actually the real
digital signal is up on 30.1 but the station selects it to show down
on 13.1. Be sure to check both places, just can't believe you can't
receive that PBS with such a good signal. Rabbit ears may be a good
start on any trouble shooting.

hdtvfan
Anonymous
November 26, 2004 4:20:44 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

rharvey422@att.net (Bob) wrote in news:5cf410c1.0411250849.23268787
@posting.google.com:

> I'm considering purchasing a new antenna preamp. The principal reason
> is that I cannot receive the digital transmission of a local PBS
> station. Their analog version comes in fine. I've checked with the
> station and they claim to be operating full time at full power. There
> are no obstructions such as hills blocking the line of sight between
> the the transmitter and my antenna.
>
> I'm currently using a 20 year old RS preamp (up to 25 db gain).
> The antenna is a new Radio Shack 120" VHF/UHF/FM.
> The cable is new RG-6 and the total run is about 30 feet from antenna
> to TV. I'm using a rotator and am sure that I have good alignment.
> The antenna is in the attic. I realize that I will probably get better
> reception by moving it outside on top of the roof, but don't want to
> do that (ugly). I do know that its not a matter of sheathing material
> because its the same as for the stations that do come in well (1"
> boards covered with ashphalt shingles). One station coming in well is
> looking through aluminum siding.
> The tv is a Sony KD-30SX955.
>
> Other stations come in fine, both in analog and digital. Some of these
> stations are transmitting a weaker signal and are further away, but
> from different directions.
>
> Is a higher gain preamp likely to improve the situation?
>
> What Radio Shack offers now claims "up to 30 db gain". I don't want to
> buy another preamp and take the time to install it if it isn't likely
> to improve anything. I understand that it is possible to overdrive the
> front end of the tv.
>
> Other than that, I'm quite impressed with the quality of the picture,
> especially HD. Even analog transmissions are far superior to what I
> was getting before on a 16 year old Akai (Mitsubishi).

Gain is not everything to consider in a preamp. In fact, that may be
your problem. For a first test, I would loop around the preamp and see
how well you do with no preamp. It may be that the signals are so strong
that they are generating intermod products in the preamp you already
have. Those can murder digital reception.


--
Dave Oldridge+
ICQ 1800667

A false witness is worse than no witness at all.
Anonymous
November 26, 2004 1:53:24 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

"Bob" <rharvey422@att.net> wrote in message news:5cf410c1.0411251623.34f58c88@posting.google.com...
> > No, not if your existing preamp is working the way it should.
> > But maybe the gain is rolling off with frequency or something.
> > Are you receiving channels both above and below the PBS ok?
> > What is the channel number?
> Its 57.1 and 57.2. Channels 56.1 and 59.1 are coming in fine.
>
> Thanks, Any recommendations on a good UHF antenna?
>
> Bob

A bow-tie array with a screen in back is often recommended by
UHF stations. Here is a 2-element indoor antenna from radio shack
for $15. I used to have a 4-element version in my attic that worked
well with an amplifier. I split the signal and distributed it around
the house.

http://www.radioshack.com/basket.asp?sku=%2C15%2D1880%2...


You might even want to see how it works next to your
TV. If it works well with no coax run, then clearly all
you have to do is insert enough gain to overcome the coax
loss.

It might be worth trying, and if it doesn't work out, just
return it. Radio Shack is pretty good about accepting returns.

Don
Anonymous
November 26, 2004 6:11:10 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

Bob wrote:
> I'm considering purchasing a new antenna preamp. The principal reason
> is that I cannot receive the digital transmission of a local PBS
> station. Their analog version comes in fine. I've checked with the
> station and they claim to be operating full time at full power. There
> are no obstructions such as hills blocking the line of sight between
> the the transmitter and my antenna.
>

Your PBS station is on two different frequencies for analog and digital
broadcasting; they may even be on opposite ends of the spectrum. As an
example, in my area WNET-TV (analog) is on channel 13 and WNET-DT
(digital) is on channel 61. Good analog reception is not a good
indicator of digital reception if the two frequencies are significantly
different.
First try, as already suggested, remove your current preamp. It could
easily do more harm then good. A poor preamp design may easily overload
and/or add more noise and contamination to the signal then what is
already there. The basic benefit of a preamp is to overcome the coaxial
line loss and any splitter loss that you may have. Therefore it should
be mounted at the antenna end. For a 100 foot cable run with RG6 the
loss is about 6 db or more at 700 Mhz (channel 52). For a 30 foot run
the coaxial loss will be about 30/100*6 db = 1.8db at 700 Mhz. Each two
way splitter adds about 4 db more loss. A few db loss is not significant
unless your reception is marginal. A few db improvement will only make a
minor difference with analog TV; but a much bigger difference with
digital TV.
A good preamp for your area might be hard to find. In my area, as an
example, I haven't found a good preamp. The signal levels are far too
high, yet I have over a 100 foot coaxial run and want to receive distant
TV stations. If your area not as severe, the Channel Master 7777 type
preamp might work fine. In general, the preamp overload capability and
noise figure parameters are far more important then preamp gain. You
only need enough gain to overcome the losses mentioned above.
Anonymous
November 26, 2004 10:04:17 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

On 25 Nov 2004 08:49:47 -0800, Bob <rharvey422@att.net> wrote:
> I'm considering purchasing a new antenna preamp. The principal reason
> is that I cannot receive the digital transmission of a local PBS
> station. Their analog version comes in fine. I've checked with the
> station and they claim to be operating full time at full power. There
> are no obstructions such as hills blocking the line of sight between
> the the transmitter and my antenna.
>
> I'm currently using a 20 year old RS preamp (up to 25 db gain).
> The antenna is a new Radio Shack 120" VHF/UHF/FM.
> The cable is new RG-6 and the total run is about 30 feet from antenna
> to TV. I'm using a rotator and am sure that I have good alignment.
> The antenna is in the attic...

How far are you from the station, and is signal strength too strong,
intermittant, or no signal at all. I am just using a Zenith Silver Sensor
(indoor UHF) on an upstairs closet shelf with 30 db RS preamp. From
Elgin, IL, I receive 23 digital channels from (13?) Chicago area stations
40-50 miles away, not including 1 station (CBS) that is VHF.

I had tried various amplified indoor antennas (with or w/o the 30 db
preamp) and they were too touchy about position and direction (maybe due
to multipath). Only one of them could just intermittantly lock onto VHF
channel 3. None of them could get all UHF channels at once like I do now.
Anonymous
November 26, 2004 11:13:37 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

At 30' a preamp will not help. It's all about signal to noise
ratio, not signal level. Get the antenna out of the attic!



"Bob" <rharvey422@att.net> wrote in message
news:5cf410c1.0411250849.23268787@posting.google.com...
> I'm considering purchasing a new antenna preamp. The principal reason
> is that I cannot receive the digital transmission of a local PBS
> station. Their analog version comes in fine. I've checked with the
> station and they claim to be operating full time at full power. There
> are no obstructions such as hills blocking the line of sight between
> the the transmitter and my antenna.
>
> I'm currently using a 20 year old RS preamp (up to 25 db gain).
> The antenna is a new Radio Shack 120" VHF/UHF/FM.
> The cable is new RG-6 and the total run is about 30 feet from antenna
> to TV. I'm using a rotator and am sure that I have good alignment.
> The antenna is in the attic. I realize that I will probably get better
> reception by moving it outside on top of the roof, but don't want to
> do that (ugly). I do know that its not a matter of sheathing material
> because its the same as for the stations that do come in well (1"
> boards covered with ashphalt shingles). One station coming in well is
> looking through aluminum siding.
> The tv is a Sony KD-30SX955.
>
> Other stations come in fine, both in analog and digital. Some of these
> stations are transmitting a weaker signal and are further away, but
> from different directions.
>
> Is a higher gain preamp likely to improve the situation?
>
> What Radio Shack offers now claims "up to 30 db gain". I don't want to
> buy another preamp and take the time to install it if it isn't likely
> to improve anything. I understand that it is possible to overdrive the
> front end of the tv.
>
> Other than that, I'm quite impressed with the quality of the picture,
> especially HD. Even analog transmissions are far superior to what I
> was getting before on a 16 year old Akai (Mitsubishi).
>
> Bob
Anonymous
November 27, 2004 5:25:13 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

"RZ" <rz@inv.invalid> wrote in message news:<10qfvneqp506426@news.supernews.com>...

> At 30' a preamp will not help. It's all about signal to noise
> ratio, not signal level. Get the antenna out of the attic!

Signal level matters sometimes when you have an indoor antenna, and
the available signal may be extremely attenuated. When dealing with
an indoor Terk type thing, cranking the gain knob up halfway may be
enough to max out the TV's signal strength meter, but sometimes
cranking it up the rest of the way is what manages to bring the
picture in.
November 28, 2004 9:54:32 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

> Winegard PR04400 or a Channel Master 4 Bow Tie works very well.
> Winegard is lots lighter in weight but works really well. Jerrold is
> another good brand but maybe hard to find.
>
> I would ask you to check for you PBS digital station on another
> channel. Seems with the digital signal they can select what channel
> they want on your digital channel readout. For instance my off-line
> PBS station is like channel 13 analog. My Dish 811 receiver shows
> them on channel 30.1 and 30.2.

I checked with the station. They are indeed transmiting on channel
57.1 and 57.2. Analog is 11. The station engineer thinks that I may
have a problem with reflections and echos, in which case and has
offered to stop by with his equipment to get some readings in the
neighborhood.

Bob
November 28, 2004 10:23:30 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

Thanks to all for the input. I think that I will try a dedicated UHF
antenna. If it helps, someone mentioned combining antennas. Does that
mean that I can connect the terminals from each antenna in parallel
before entering the preamp? Should I disconnect the UHF part of my
VHF/UHF/FM antenna?

This will probably only be a temporary connection because I now
receive all but one VHF station on their new UHF channels.
Unfortunately, the missing one is one of my favorites, another PBS
station. Although the FCC site indicates that they have been assigned
channel 19, I'm receiving them on 2.1 and 2.2. This concurrs with the
schedule posted on their web site where they make no mention of
channel 19. I'm not sure how that all works. Some stations are sending
digital signals out on the VHF band as well as on UHF. I.e., Boston's
Channel 5 comes in on 5.1, 5.2, 20.1 & 20.2.

I'm guessing that since new UHF channels have been assigned that the
FCC will eventually take back the frequencies occupied by channels 2
through 13.

Bob
Anonymous
November 28, 2004 11:38:58 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

paul-NOZPAM@paulkienitz.net (Paul Kienitz) wrote in
news:e5747637.0411271425.648341b3@posting.google.com:

> "RZ" <rz@inv.invalid> wrote in message
> news:<10qfvneqp506426@news.supernews.com>...
>
>> At 30' a preamp will not help. It's all about signal to noise
>> ratio, not signal level. Get the antenna out of the attic!
>
> Signal level matters sometimes when you have an indoor antenna, and
> the available signal may be extremely attenuated. When dealing with
> an indoor Terk type thing, cranking the gain knob up halfway may be
> enough to max out the TV's signal strength meter, but sometimes
> cranking it up the rest of the way is what manages to bring the
> picture in.

A lot of indoor reception problems are exacerbated by interference from
computers and other household electronics. That's why a good outdoor
antenna with a balun, rotor and good RG6 coax is often a good answer to
problems. A preamp may help too, in low signal areas, but the real
killer in digital TV is signal-to-noise and reflected ghost signals, as
well as other interference are noise to the digital modem even though
they may count as signal to a signal-strength meter. The trick is to
eliminate as many reflected signals as you can (or sometimes to pick one
strong one out from the "jungle").

--
Dave Oldridge+
ICQ 1800667

A false witness is worse than no witness at all.
Anonymous
November 28, 2004 11:38:59 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

In article <Xns95AF80AFA4109doldridgsprintca@24.71.223.159>,
doldridg@leavethisoutshaw.ca says...
> problems. A preamp may help too, in low signal areas, but the real
> killer in digital TV is signal-to-noise and reflected ghost signals, as
> well as other interference are noise to the digital modem even though
> they may count as signal to a signal-strength meter.

AFAIK, all current digital tuner "signal strentgh" readouts read the
inverse of the BER (ie, 1/BER) so garbage doesn't count as singal.
Adding 20-30dB of preamp often doesn't change the "signal strength"
reading, because the reading is effectively SNR, and not strength.

/Chris, AA6SQ
Anonymous
November 29, 2004 12:19:21 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

In article <5cf410c1.0411281923.43038288@posting.google.com>,
rharvey422@att.net says...
> I'm guessing that since new UHF channels have been assigned that the
> FCC will eventually take back the frequencies occupied by channels 2
> through 13.

Not necessarily. Currently, stations have to give back either the
old or new channel and the choice is up to them. There are reasons
to prefer the old channels.

/Chris
Anonymous
November 29, 2004 2:41:24 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

"Bob" <rharvey422@att.net> wrote in message news:5cf410c1.0411281923.43038288@posting.google.com...
> Thanks to all for the input. I think that I will try a dedicated UHF
> antenna. If it helps, someone mentioned combining antennas. Does that
> mean that I can connect the terminals from each antenna in parallel
> before entering the preamp? Should I disconnect the UHF part of my
> VHF/UHF/FM antenna?

For this purpose, you need a special type of combiner where one path
will pass only VHF channels and the other path passes only UHF channels.

For an example, see http://www.abccables.com/201-604.html

You would not have to disconnect the UHF part of the VHF/UHF/FM antenna
because its UHF signal would not get thru the VHF port of the combiner.

Don
Anonymous
November 29, 2004 5:27:42 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

Chris Thomas (cthomas@mminternet.com) wrote in alt.tv.tech.hdtv:
> AFAIK, all current digital tuner "signal strentgh" readouts read the
> inverse of the BER (ie, 1/BER) so garbage doesn't count as singal.

This isn't true in all cases. As an example, the MIT MDP-120 MyHD PCI
card has what looks like the same kind of signal meter, but it is *not*
the inverse of the correctable error rate. Those numbers can be found
using another program supplied with the card, and I often get zero
correctable errors in a given sampling period yet the "strength" meter
isn't 100% during that same period.

Similarly, an error rate that is on the threshold of being "too much" (it's
something like 512 errors per sampling period, but don't quote me on the
number...I'm not near that machine) doesn't give a near-zero reading on the
"strength" meter.

> Adding 20-30dB of preamp often doesn't change the "signal strength"
> reading, because the reading is effectively SNR, and not strength.

Likewise, the MyHD "strength" meter isn't pure S/N (or, more correctly for
ATSC, carrier-to-noise) either. A station with a C/N of 25dB and about
10 correctable errors per sampling period has a "strength" meter reading
*lower* than a station with C/N of 22dB and zero correctable errors.

--
Jeff Rife |
SPAM bait: | http://www.nabs.net/Cartoons/OverTheHedge/TiVoForRealLi...
AskDOJ@usdoj.gov |
spam@ftc.gov |
Anonymous
November 29, 2004 2:20:22 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

"Jeff Rife" <wevsr@nabs.net> wrote in message
news:MPG.1c14997445fb8fdf989956@news.nabs.net...
> Chris Thomas (cthomas@mminternet.com) wrote in alt.tv.tech.hdtv:
> > AFAIK, all current digital tuner "signal strentgh" readouts read the
> > inverse of the BER (ie, 1/BER) so garbage doesn't count as singal.
>
> This isn't true in all cases. As an example, the MIT MDP-120 MyHD PCI
> card has what looks like the same kind of signal meter, but it is *not*
> the inverse of the correctable error rate. Those numbers can be found
> using another program supplied with the card, and I often get zero
> correctable errors in a given sampling period yet the "strength" meter
> isn't 100% during that same period.
>
> Similarly, an error rate that is on the threshold of being "too much"
(it's
> something like 512 errors per sampling period, but don't quote me on the
> number...I'm not near that machine) doesn't give a near-zero reading on
the
> "strength" meter.
>
> > Adding 20-30dB of preamp often doesn't change the "signal strength"
> > reading, because the reading is effectively SNR, and not strength.
>
> Likewise, the MyHD "strength" meter isn't pure S/N (or, more correctly for
> ATSC, carrier-to-noise) either. A station with a C/N of 25dB and about
> 10 correctable errors per sampling period has a "strength" meter reading
> *lower* than a station with C/N of 22dB and zero correctable errors.
>
I feel kinda unsure of myself here as I don't have the equipment to confirm
the following observations:
FM interferance or harmonic distortion (overdrive) is a much more serious
problem than AM noise for a digital signal. Adaptive equalization can
sample the digital signal quite a few DB under the peak signal where noise
and ghosts are generally seen.

In my openion it's not worth buying a Radio shack 30db (4db noise) antenna
amp over the CM7777 which is 26db (2db noise) as the CM is harder to
overdrive and has less harmonic distortion. It's particuarlly important for
head end applications where this signal is going to be further amplified.
The Radio shack with it's 4 db of gain over the CM will pull in stations
that are further away in some applications but it adds to potential problems
in other cases.

The point is that you have to know what kind of noise you are talking about
and lumping FM, AM, co-channel, harmonic distortion and ghosts as noise
confuses the issue which is trying to fix the reception.

It's hard for me to know what's the problem.
Anonymous
November 29, 2004 7:15:10 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

Chris Thomas <cthomas@mminternet.com> wrote in
news:MPG.1c1420d71c8ef0b1989877@news.mminternet.com:

> In article <Xns95AF80AFA4109doldridgsprintca@24.71.223.159>,
> doldridg@leavethisoutshaw.ca says...
>> problems. A preamp may help too, in low signal areas, but the real
>> killer in digital TV is signal-to-noise and reflected ghost signals,
as
>> well as other interference are noise to the digital modem even though
>> they may count as signal to a signal-strength meter.
>
> AFAIK, all current digital tuner "signal strentgh" readouts read the
> inverse of the BER (ie, 1/BER) so garbage doesn't count as singal.
> Adding 20-30dB of preamp often doesn't change the "signal strength"
> reading, because the reading is effectively SNR, and not strength.

That's a much more sensible reading than mere signal strength, for sure.
And in that case, slipping an attenuator in the line (where signals are
very strong but unreadable) may just improve the number considerably,
since (internally-produced) third-order intermod products (the most
likely to be loud and in-band) will be attenuated by three times the
number of decibels the attenuator is raking off the actual signal.

--
Dave Oldridge+
ICQ 1800667

A false witness is worse than no witness at all.
Anonymous
November 30, 2004 5:57:14 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

rharvey422@att.net (Bob) wrote:

>Thanks to all for the input. I think that I will try a dedicated UHF
>antenna. If it helps, someone mentioned combining antennas. Does that
>mean that I can connect the terminals from each antenna in parallel
>before entering the preamp? Should I disconnect the UHF part of my
>VHF/UHF/FM antenna?

Don't just parallel them; use a UHF/VHF combiner (a UHF/VHF splitter
hooked up backwards usually works just fine).
>
>This will probably only be a temporary connection because I now
>receive all but one VHF station on their new UHF channels.
>Unfortunately, the missing one is one of my favorites, another PBS
>station. Although the FCC site indicates that they have been assigned
>channel 19, I'm receiving them on 2.1 and 2.2. This concurrs with the
>schedule posted on their web site where they make no mention of
>channel 19. I'm not sure how that all works. Some stations are sending
>digital signals out on the VHF band as well as on UHF. I.e., Boston's
>Channel 5 comes in on 5.1, 5.2, 20.1 & 20.2.

No, the actual digital broadcast is just on Channel 20. But it
includes information telling the receiver to remap it as being on
Channel 5, the analog broadcast's channel that everyone is familiar
with. Stations promote their channel numbers heavily, and they don't
want their viewers to have to learn new ones.
>
>I'm guessing that since new UHF channels have been assigned that the
>FCC will eventually take back the frequencies occupied by channels 2
>through 13.

I'd heard that, but I've also heard they have the option to keep their
old channel and drop the new one. And some are broadcasting digital
on VHF. In my area we have one on VHF and another scheduled to start
in January. I wish they'd all go to UHF; then I could remove the big
VHF antenna that's in my way when I go to the attic. My UHF antenna
is a 4-bay bowtie on a dowel in a Christmas tree stand; it doesn't
take up much room.

Del Mibbler <mibbler@nycap.rr.com>
Anonymous
December 26, 2004 9:35:24 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

Did the engineer stop by?
Did you resolve this problem?


"Bob" <rharvey422@att.net> wrote in message
news:5cf410c1.0411281854.599f45b5@posting.google.com...
>> Winegard PR04400 or a Channel Master 4 Bow Tie works very well.
>> Winegard is lots lighter in weight but works really well. Jerrold is
>> another good brand but maybe hard to find.
>>
>> I would ask you to check for you PBS digital station on another
>> channel. Seems with the digital signal they can select what channel
>> they want on your digital channel readout. For instance my off-line
>> PBS station is like channel 13 analog. My Dish 811 receiver shows
>> them on channel 30.1 and 30.2.
>
> I checked with the station. They are indeed transmiting on channel
> 57.1 and 57.2. Analog is 11. The station engineer thinks that I may
> have a problem with reflections and echos, in which case and has
> offered to stop by with his equipment to get some readings in the
> neighborhood.
>
> Bob
!