OTA TV reception problems

[Michael A. Terrell]

Jeff Liebermann wrote:

On Sat, 12 Nov 2016 06:32:48 -0500, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

http://www.blondertongue.com/UserFiles/file/documents/2012%20BRG%20FINAL_lo-res.pdf

I have several other dates archived, as well. Sometimes you need the
older information for existing systems.

Thanks, but the 2014 version is more current:
http://www.blondertongue.com/UserFiles/file/Marketing%20Literature/2014_BRG_lo-res.pdf
Other documents and catalogs might be of interest:
http://www.blondertongue.com/about/request_a_catalog.aspx

Several other companies had useful publications, but the slow
conversion to Fiber Aided CATV killed them off.


--
Never piss off an Engineer!

They don't get mad.

They don't get even.

They go for over unity! ;-)

 

[Michael A. Terrell]

Jeff Liebermann wrote:

On Sat, 12 Nov 2016 23:25:15 -0500, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

Jeff Liebermann wrote:
On Sat, 12 Nov 2016 06:32:48 -0500, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

http://www.blondertongue.com/UserFiles/file/documents/2012%20BRG%20FINAL_lo-res.pdf

I have several other dates archived, as well. Sometimes you need the
older information for existing systems.

Good point (after I erased the 2012 version from my machine).
I did some Googling and found the 2008 version of the Blonder Tongue
guide at:
https://www.sateng.com/downloads/btbroadbandrefguide.pdf
After a quick glance, it seems to have quite a bit on antenna systems,
which are not used very much these days thanks to fiber and satellite
backhauls.

Also, the 2009 version at:
http://www.blondertongue.com/UserFiles/file/documents/2009%20BBand%20Ref%20Guide.pdf

Thanks, but the 2014 version is more current:
http://www.blondertongue.com/UserFiles/file/Marketing%20Literature/2014_BRG_lo-res.pdf
Other documents and catalogs might be of interest:
http://www.blondertongue.com/about/request_a_catalog.aspx

Several other companies had useful publications, but the slow
conversion to Fiber Aided CATV killed them off.

The Motorola (now Arris) 2014 guide is what I like to use:
https://www.arris.com/globalassets/resources/other/cable_technology_pocket_guide.pdf
(6MB) 302 pages.

Just like early electrical engineering books that explained the
things that are just glossed over in current books. P Millet's website
is a wealth of early electronics books.


--
Never piss off an Engineer!

They don't get mad.

They don't get even.

They go for over unity! ;-)

 

[Jeff Liebermann]

On Sun, 13 Nov 2016 15:53:54 -0500, "Michael A. Terrell"
<mike.terrell@earthlink.net> wrote:

Just like early electrical engineering books that explained the
things that are just glossed over in current books. P Millet's website
is a wealth of early electronics books.

Yep.
<http://www.tubebooks.org/technical_books_online.htm>
I downloaded a mess of those (mostly radio books) a few years ago and
amd sloooowly going through them. What's interesting to me is that
the origins or reasons behind various modern technical decisions and
standards can be found in the old books.

However, I doubt any of this will help deal with the current OTA TV
reception problem. I'm not getting any response from CaptainVideo so
I guess I'll drop the project for now.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

captainvideo:

Your problem is two-fold: distance, and
the all-digital broadcast requirement.


8 years ago, on NTSC(analog), distance
would not have been been such an issue.
You probably would have had snow on
a lot of channels, but you still had picture
and sound.


Now, on ATSC(digital), you don't get certain
stations at all, and frequent dropouts on
others.

This is why I maintain that ATSC is 'less
Green' than NTSC was: While with
digital stations can piggy-back channels
(4.2, 4.3, 4.4, etc.) they must BOOST
THEIR SIGNAL for people with same
OTA setup to receive them in the first
place. And increasing signal strength
meansUSING MORE ENERGY - something
the folks over at Alt.Video.Digital.Tv fail
to grasp.

You said you are using a 'parabolic' antenna
currently - I'm assuming that is dish-shaped.

Have you looked into a variation on this
form factor yet? It's all I'll ever use, even
just 35 miles away from my market:

https://m.lowes.com/pd/Channel-Master-Outdoor-Non-Amplified-Yagi-Type-Antenna/50005786?cm_mmc=SCE_PLA_ONLY-_-RoughPlumbingElectrical-_-SosHomeAutomation-Communication-_-50005786:Channel_Master&CAWELAID=&kpid=50005786&CAGPSPN=pla&k_clickID=35fefdd1-395a-47bd-a160-f2260ea5c961

 

Pat wrote: "You may fail to grasp it, too. When you hear about TV stations
(especially UHF stations) using millions of watts of power, they are
referring to ERP - Effective Radiated Power. That means the actual
power going into the antenna is much lower but the antenna has very
high gain. Rarely do stations use more than a few thousand watts of
actual power. The transmitter's actual power usage is a drop in the
bucket compared to all the other energy a TV station uses for lights,
cameras, HVAC, etc. "

________
Alright, say a typical medium market
station has historically transmitted
2,000W as a NTSC. 2009 they go
fully ATSC, still at 2,000W. Hundreds
of letters from viewers flood their
mailbox, and thousands of callers
jam their phone boards about not
being able to pick them up over the
air with their new TVs. Most are from
viewers in the outer one-third of the
station's transmission radius.


Station board deliberates, and
after a couple months decides to
increase transmitter wattage to 2,500W.
Viewer complaints plummet, while
greenhouse gas emmissions steadily
rise to generate additional electricity as
this scenario is mulitiplied across dozens
of medium markets and many major
markets.

Grasp that!


Yeah, I get that actual wattage is but
a fraction of ERP, but it still adds up
as many TV stations must increase their
signal strength to cover the same
audience area in digital as they did
via analog.

 

[Pat]

On Tue, 15 Nov 2016 04:10:07 -0800 (PST), thekmanrocks@gmail.com
wrote:

And increasing signal strength
meansUSING MORE ENERGY - something
the folks over at Alt.Video.Digital.Tv fail
to grasp.

You may fail to grasp it, too. When you hear about TV stations
(especially UHF stations) using millions of watts of power, they are
referring to ERP - Effective Radiated Power. That means the actual
power going into the antenna is much lower but the antenna has very
high gain. Rarely do stations use more than a few thousand watts of
actual power. The transmitter's actual power usage is a drop in the
bucket compared to all the other energy a TV station uses for lights,
cameras, HVAC, etc.

 

[Jeff Liebermann]

On Sun, 6 Nov 2016 16:40:35 -0800 (PST), captainvideo462009@gmail.com
wrote:
(...)

This is too easy.
WBZ has been running on reduced power for most of the last few weeks
thanks to an antenna problem:
<http://boston.cbslocal.com/2016/11/07/wbz-tv-wsbk-tv-operating-at-reduced-power/>
<http://boston.cbslocal.com/2016/10/22/transmission-issue-causes-outage-for-some-wbz-tv-viewers/>
No clue if it has been fixed, but judging by the lack of updates,
probably not.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Pat]

On Tue, 15 Nov 2016 08:31:32 -0800 (PST), thekmanrocks@gmail.com
wrote:

Pat wrote: "You may fail to grasp it, too. When you hear about TV stations
(especially UHF stations) using millions of watts of power, they are
referring to ERP - Effective Radiated Power. That means the actual
power going into the antenna is much lower but the antenna has very
high gain. Rarely do stations use more than a few thousand watts of
actual power. The transmitter's actual power usage is a drop in the
bucket compared to all the other energy a TV station uses for lights,
cameras, HVAC, etc. "

________
Alright, say a typical medium market
station has historically transmitted
2,000W as a NTSC. 2009 they go
fully ATSC, still at 2,000W. Hundreds
of letters from viewers flood their
mailbox, and thousands of callers
jam their phone boards about not
being able to pick them up over the
air with their new TVs. Most are from
viewers in the outer one-third of the
station's transmission radius.


Station board deliberates, and
after a couple months decides to
increase transmitter wattage to 2,500W.
Viewer complaints plummet, while
greenhouse gas emmissions steadily
rise to generate additional electricity as
this scenario is mulitiplied across dozens
of medium markets and many major
markets.

Grasp that!

Don't forget the part where they have to modify their license at the
FCC after hiring engineers to show that the increased power doesn't
cause interference with any other licensed station in the area (or in
Canada). That process can takes a long time and is expensive even
before equipment is purchased. Most of the applications are on hold
right now waiting for the auctions to be complete. ATSC has lots of
issues, but creating a significant increase in greenhouse gases isn't
one of them.

Yeah, I get that actual wattage is but
a fraction of ERP, but it still adds up
as many TV stations must increase their
signal strength to cover the same
audience area in digital as they did
via analog.

 

[Michael A. Terrell]

Pat wrote:

On Tue, 15 Nov 2016 04:10:07 -0800 (PST), thekmanrocks@gmail.com
wrote:

And increasing signal strength
meansUSING MORE ENERGY - something
the folks over at Alt.Video.Digital.Tv fail
to grasp.


You may fail to grasp it, too. When you hear about TV stations
(especially UHF stations) using millions of watts of power, they are
referring to ERP - Effective Radiated Power. That means the actual
power going into the antenna is much lower but the antenna has very
high gain. Rarely do stations use more than a few thousand watts of
actual power. The transmitter's actual power usage is a drop in the
bucket compared to all the other energy a TV station uses for lights,
cameras, HVAC, etc.

I was an engineer at an analog UHF station with a 5 MW EIRP, on a
1700' tower. The Comark transmitter used a pair of 65 KW EEV Klystons,
for 130 KW of RF into the diplexer. A third 65 KW Klystron was used for
the aural signal. That was in the late '80s, and our electric bill for
the transmitter site was $45,00 a month.

Solid state transmitters are modular, with around 1KW output, per
tray. Look at the Harris Broadcast website for some actual data.


--
Never piss off an Engineer!

They don't get mad.

They don't get even.

They go for over unity! ;-)

 

[Clifford Heath]

On 18/11/16 13:44, Michael A. Terrell wrote:

Pat wrote:
Solid state transmitters are modular, with around 1KW output, per
tray. Look at the Harris Broadcast website for some actual data.

I have a half-dozen such modules here, unfortunately
with the water-cooled heatsink removed, if you want
photos or to ask any questions. The modules are single
or dual, using a BLF278 dual FET each. A 30W input is
split into six to drive three duals, which are then
combined to produce about 1KW from about 6KW input at
50V. The power supply rectifies three-phase 415V mains
and chopped it to produce 50V at 60A, scary.

A local ATV transmitter was using more than 50 of these
to put 50KW up the spout. Pretty old-tech now though,
the new lateral MOSFETs from NXP produce 1500W from a
single device (two FETs), as Michael T has pointed out
recently.

The really interesting bit to me is how simple the baluns
are - just a couple of 8cm lengths of special hardline
to match from about 12 ohms up to 50, at 225MHz.
Transmission line transformers FTW! There's quite a few
reference designs for this class of transmitter at
http://nxp.com

Clifford Heath.

 

Clifford, Michael:

So you're saying modern ATSC transmitters
actually use less power then the old NTs?

 

[amdx]

On 11/10/2016 11:28 AM, Jeff Liebermann wrote:

On Tue, 8 Nov 2016 13:56:36 -0800 (PST), captainvideo462009@gmail.com
wrote:

I would try what the station engineer pointed out.
You have a high gain antenna and a 28db amplifier, try it without the
amp.
I'm 51.9 miles* from a digital channel 36, I cut a folded dipole using
300 ohm twin lead, as I recall about 9.5" long. No Amp. It is no more
than 10ft off the ground. I have zero dropouts and no audio problems.

WTVY
> http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3ddfaf29715115ab

Opps, just saw a glitch go by in the video.

Mikek


*According to TVfool.

 

[amdx]

On 11/15/2016 11:09 AM, Jeff Liebermann wrote:

On Sun, 6 Nov 2016 16:40:35 -0800 (PST), captainvideo462009@gmail.com
wrote:
(...)

This is too easy.
WBZ has been running on reduced power for most of the last few weeks
thanks to an antenna problem:
http://boston.cbslocal.com/2016/11/07/wbz-tv-wsbk-tv-operating-at-reduced-power/
http://boston.cbslocal.com/2016/10/22/transmission-issue-causes-outage-for-some-wbz-tv-viewers/
No clue if it has been fixed, but judging by the lack of updates,
probably not.

Well that takes all the fun out of it!
But do note my post of good reception at 51.9m miles with
cut to length folded dipole, 10 ft off the ground.
Channel 36, about 9.5" long.
Mikek

 

[Jeff Liebermann]

On Fri, 18 Nov 2016 15:06:37 -0600, amdx <nojunk@knology.net> wrote:

On 11/15/2016 11:09 AM, Jeff Liebermann wrote:
On Sun, 6 Nov 2016 16:40:35 -0800 (PST), captainvideo462009@gmail.com
wrote:
(...)

This is too easy.
WBZ has been running on reduced power for most of the last few weeks
thanks to an antenna problem:
http://boston.cbslocal.com/2016/11/07/wbz-tv-wsbk-tv-operating-at-reduced-power/
http://boston.cbslocal.com/2016/10/22/transmission-issue-causes-outage-for-some-wbz-tv-viewers/
No clue if it has been fixed, but judging by the lack of updates,
probably not.

Well that takes all the fun out of it!

Occam's Razor.

But do note my post of good reception at 51.9m miles with
cut to length folded dipole, 10 ft off the ground.
Channel 36, about 9.5" long.
Mikek

Sure, it can be done at 45 miles depending on tx power and frequency.
However, Captain Video has an additional problem in the form of a
mound of dirt in between his antenna and the station transmitter.
<http://802.11junk.com/jeffl/coverage/KBCZ-WBZ/WBZ-Lenny.jpg>
or if you have Google Earth handy:
<http://802.11junk.com/jeffl/coverage/KBCZ-WBZ/WBZ%20path.kmz>
The above path profile is NOT very accurate. I stopped working on the
problem after Captain Video disappeared from the thread.

Incidentally, I sometimes can watch KMPH TV from Fresno, CA which is
about 200 miles away from Ben Lomond. I live on the side of a hill
which helps. The real culprit is atmosheric ducting and edge
diffraction from two mountain ranges in between. It only happens a
few days per year, usually in the summer, but the picture is 100%
perfect.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[amdx]

On 11/18/2016 5:02 PM, Jeff Liebermann wrote:

On Fri, 18 Nov 2016 15:06:37 -0600, amdx <nojunk@knology.net> wrote:

On 11/15/2016 11:09 AM, Jeff Liebermann wrote:
On Sun, 6 Nov 2016 16:40:35 -0800 (PST), captainvideo462009@gmail.com
wrote:
(...)

This is too easy.
WBZ has been running on reduced power for most of the last few weeks
thanks to an antenna problem:
http://boston.cbslocal.com/2016/11/07/wbz-tv-wsbk-tv-operating-at-reduced-power/
http://boston.cbslocal.com/2016/10/22/transmission-issue-causes-outage-for-some-wbz-tv-viewers/
No clue if it has been fixed, but judging by the lack of updates,
probably not.

Well that takes all the fun out of it!

Occam's Razor.

But do note my post of good reception at 51.9m miles with
cut to length folded dipole, 10 ft off the ground.
Channel 36, about 9.5" long.
Mikek

Sure, it can be done at 45 miles depending on tx power and frequency.
However, Captain Video has an additional problem in the form of a
mound of dirt in between his antenna and the station transmitter.
http://802.11junk.com/jeffl/coverage/KBCZ-WBZ/WBZ-Lenny.jpg
or if you have Google Earth handy:
http://802.11junk.com/jeffl/coverage/KBCZ-WBZ/WBZ%20path.kmz
The above path profile is NOT very accurate. I stopped working on the
problem after Captain Video disappeared from the thread.

Incidentally, I sometimes can watch KMPH TV from Fresno, CA which is
about 200 miles away from Ben Lomond. I live on the side of a hill
which helps. The real culprit is atmosheric ducting and edge
diffraction from two mountain ranges in between. It only happens a
few days per year, usually in the summer, but the picture is 100%
perfect.

When I was a lot younger living in Kalamazoo Michigan, late one night
I received a Wisconsin TV station across lake Michigan.

Mikek

 

[Michael A. Terrell]

thekmanrocks@gmail.com wrote:

Clifford, Michael:

So you're saying modern ATSC transmitters
actually use less power then the old NTs?

The heaters in Klystons used a lot of power, that had to be removed as
heat, in a water chiller. One 25 KW UHF transmitter that I rebuilt used
a pair of 1.5V, 1000A heaters per tube. That was 3 KW, then the fan on
the water chiller was a 480V, three phase, 5 hp motor. The circulating
pump was anther two HP. None of this ended up at the output port.


--
Never piss off an Engineer!

They don't get mad.

They don't get even.

They go for over unity! ;-)

 

Michael Terrell wrote: - hide quoted text -
thekma...@gmail.com wrote:

Clifford, Michael:

So you're saying modern ATSC transmitters
actually use less power then the old NTs?

"The heaters in Klystons used a lot of power, that had to be removed as
heat, in a water chiller. One 25 KW UHF transmitter that I rebuilt used
a pair of 1.5V, 1000A heaters per tube. That was 3 KW, then the fan on
the water chiller was a 480V, three phase, 5 hp motor. The circulating
pump was anther two HP. None of this ended up at the output port. "
- show quoted text -


That doesn't answer my question of whether
or not AT transmitters use less power than
NT. Just a simple Yes or No would suffice.

 

[Tony Matt]

On 11/15/2016 12:09 PM, Jeff Liebermann wrote:

On Sun, 6 Nov 2016 16:40:35 -0800 (PST), captainvideo462009@gmail.com
wrote:
(...)

This is too easy.
WBZ has been running on reduced power for most of the last few weeks
thanks to an antenna problem:
http://boston.cbslocal.com/2016/11/07/wbz-tv-wsbk-tv-operating-at-reduced-power/
http://boston.cbslocal.com/2016/10/22/transmission-issue-causes-outage-for-some-wbz-tv-viewers/
No clue if it has been fixed, but judging by the lack of updates,
probably not.

The problem (defective transmission line to the upper master antenna on
the CBS tower in Needham) was finally fully resolved this morning at
4:55AM. Lots more details at
http://www.wgbh.org/about/Tower_and_Transmission_Signal_Issues.cfm
(The CBS tower carries virtual channels 2, 4, 5, 8, 38, 44, and 48.)

Tony Matt

 

On Saturday, November 19, 2016 at 2:52:21 AM UTC-5, thekma...@gmail.com wrote:

Michael Terrell wrote: - hide quoted text -
thekma...@gmail.com wrote:
Clifford, Michael:

So you're saying modern ATSC transmitters
actually use less power then the old NTs?


"The heaters in Klystons used a lot of power, that had to be removed as
heat, in a water chiller. One 25 KW UHF transmitter that I rebuilt used
a pair of 1.5V, 1000A heaters per tube. That was 3 KW, then the fan on
the water chiller was a 480V, three phase, 5 hp motor. The circulating
pump was anther two HP. None of this ended up at the output port. "
- show quoted text -


That doesn't answer my question of whether
or not AT transmitters use less power than
NT. Just a simple Yes or No would suffice.

there is not a simple answer..

if the station stayed on the same frequency, then it can use lower power digital compared to analog. Digital fundamentally requires less power to close the link.

HOWEVER.

many stations also switched from a VHF frequency to a UHF frequency.
The FCC allows more power to be used on UHF.

So in each case the answer is ...it depends.

I think it would be a gross exaggeration to say that digital TV is environmentally more friendly compared to analog because of power consumption.

m

 

[Ralph Mowery]

In article <01f5802b-4edd-48e1-9216-80bbb818d031@googlegroups.com>,
makolber@yahoo.com says...

That doesn't answer my question of whether
or not AT transmitters use less power than
NT. Just a simple Yes or No would suffice.

there is not a simple answer..

if the station stayed on the same frequency, then it can use lower power digital compared to analog. Digital fundamentally requires less power to close the link.

HOWEVER.

many stations also switched from a VHF frequency to a UHF frequency.
The FCC allows more power to be used on UHF.

So in each case the answer is ...it depends.

I think it would be a gross exaggeration to say that digital TV is environmentally more friendly compared to analog because of power consumption.

m

There is another factor also. For the same bandwidth there can be
several low resolution TV 'chanels' on the same ammount of bandwidth as
one analog tv chanel.