Group B aerial query

Bill Wright wrote:
Steve Terry wrote:

Interesting, those figures suggest that group A aerials centre around
channel 32 tailing off at 21 and 43 (+- 11 channels)

When one would expect centring on around 28 (+- 7 channels)
ch 21 to 35

So Group A aerial are generally cut on the short side (maybe to save
metal?) Steve Terry

Because the frequency response of a yagi is not symmetrical the peak
is usually only four to six channels below the highest required
channel. It's physics, not chicanery.
Bill

A dipole is symmetrical, a yagi won't be because of the distance
between the elements, so if they were distanced on the long instead
of short side then the response bias would be the other way

Steve Terry
--
Get a free GiffGaff PAYG Sim and £5 bonus after activation at:
http://giffgaff.com/orders/affiliate/gfourwwk

Steve Terry wrote:

Because the frequency response of a yagi is not symmetrical the peak
is usually only four to six channels below the highest required
channel. It's physics, not chicanery.
Bill

A dipole is symmetrical, a yagi won't be because of the distance
between the elements, so if they were distanced on the long instead
of short side then the response bias would be the other way

Could you elucidate? I'm sorry but I don't follow.

Bill

In article , Bill Wright
scribeth thus
Steve Terry wrote:

Because the frequency response of a yagi is not symmetrical the peak
is usually only four to six channels below the highest required
channel. It's physics, not chicanery.
Bill

A dipole is symmetrical, a yagi won't be because of the distance
between the elements, so if they were distanced on the long instead
of short side then the response bias would be the other way

Could you elucidate? I'm sorry but I don't follow.

Bill

I've just dragged up a couple of stock Yagi designs in WINNEC and around
10 meg either side the VSWR and gain are doing interesting things.

There doesn't seem to be any particular lopsided "ness" but its very
apparent that the gain and bandwidth are somewhat divorced from each
other;!.

And thats over 10 MHz not more..
--
Tony Sayer

"Scott" wrote in message
...
On Sat, 20 Jul 2013 18:17:27 +0100, "R. Mark Clayton"
wrote:


"Scott" wrote in message
. ..
Following upon my previous posting, according to Brian Butterworth's
site http://www.ukfree.tv/fullstory.php?storyid=1107052119 the extra
frequences here will be 32 and 35. I understand Group B aerials cover
channels 35 to 53. In the considered opinion of the experts, am I
likely to require a new aerial or is 32 close enough to 35 to provide
an adequate albeit attenuated signal?

It will probably work the roll off is fairly shallow (but will depend a
bit
on how many elements)

Looks like 11 elements (plus the reflector).

I could get a Group K aerial I suppose as my main concern at the time
was to try to minimise any 4G signals.

Put a filter on if it is actually a problem, far higher selectivity than a
shortish aerial.

On Sat, 27 Jul 2013 18:31:20 +0100, "R. Mark Clayton"
wrote:


"Scott" wrote in message
.. .
On Sat, 20 Jul 2013 18:17:27 +0100, "R. Mark Clayton"
wrote:


"Scott" wrote in message
...
Following upon my previous posting, according to Brian Butterworth's
site http://www.ukfree.tv/fullstory.php?storyid=1107052119 the extra
frequences here will be 32 and 35. I understand Group B aerials cover
channels 35 to 53. In the considered opinion of the experts, am I
likely to require a new aerial or is 32 close enough to 35 to provide
an adequate albeit attenuated signal?

It will probably work the roll off is fairly shallow (but will depend a
bit
on how many elements)

Looks like 11 elements (plus the reflector).

I could get a Group K aerial I suppose as my main concern at the time
was to try to minimise any 4G signals.

Put a filter on if it is actually a problem, far higher selectivity than a
shortish aerial.

Thanks. I'm not expecting a problem. It's a high aerial with no base
stations nearby that I know about, pointing at a main transmitter. The
highest channel number is 47 so I am optimistic at the moment!

"Scott" wrote in message
...
On Sat, 27 Jul 2013 18:31:20 +0100, "R. Mark Clayton"
wrote:


"Scott" wrote in message
. ..
On Sat, 20 Jul 2013 18:17:27 +0100, "R. Mark Clayton"
wrote:


"Scott" wrote in message
m...
Following upon my previous posting, according to Brian
Butterworth's
site http://www.ukfree.tv/fullstory.php?storyid=1107052119
the extra
frequences here will be 32 and 35. I understand Group B
aerials cover
channels 35 to 53. In the considered opinion of the
experts, am I
likely to require a new aerial or is 32 close enough to 35
to provide
an adequate albeit attenuated signal?

It will probably work the roll off is fairly shallow (but
will depend a
bit
on how many elements)

Looks like 11 elements (plus the reflector).

I could get a Group K aerial I suppose as my main concern at
the time
was to try to minimise any 4G signals.

Put a filter on if it is actually a problem, far higher
selectivity than a
shortish aerial.

Thanks. I'm not expecting a problem. It's a high aerial with
no base
stations nearby that I know about, pointing at a main
transmitter. The
highest channel number is 47 so I am optimistic at the moment!



Er, the likelihood is that if the highest channel is 47 and it
has a full compliment of six muxes then those in the 40's are for
the additional muxes and your core muxes (BBC, basic ITV and HD)
will all be in the 20's and 30's. In that case a B-group may not
be the best option. Six-mux transmitters in B-group all have TX's
in the 50's.



--
Woody

harrogate three at ntlworld dot com

On Tue, 30 Jul 2013 17:04:35 +0100, "Woody"
wrote:

"Scott" wrote in message
.. .
On Sat, 27 Jul 2013 18:31:20 +0100, "R. Mark Clayton"
wrote:


"Scott" wrote in message
...
On Sat, 20 Jul 2013 18:17:27 +0100, "R. Mark Clayton"
wrote:


"Scott" wrote in message
om...
Following upon my previous posting, according to Brian
Butterworth's
site http://www.ukfree.tv/fullstory.php?storyid=1107052119
the extra
frequences here will be 32 and 35. I understand Group B
aerials cover
channels 35 to 53. In the considered opinion of the
experts, am I
likely to require a new aerial or is 32 close enough to 35
to provide
an adequate albeit attenuated signal?

It will probably work the roll off is fairly shallow (but
will depend a
bit
on how many elements)

Looks like 11 elements (plus the reflector).

I could get a Group K aerial I suppose as my main concern at
the time
was to try to minimise any 4G signals.

Put a filter on if it is actually a problem, far higher
selectivity than a
shortish aerial.

Thanks. I'm not expecting a problem. It's a high aerial with
no base
stations nearby that I know about, pointing at a main
transmitter. The
highest channel number is 47 so I am optimistic at the moment!



Er, the likelihood is that if the highest channel is 47 and it
has a full compliment of six muxes then those in the 40's are for
the additional muxes and your core muxes (BBC, basic ITV and HD)
will all be in the 20's and 30's. In that case a B-group may not
be the best option. Six-mux transmitters in B-group all have TX's
in the 50's.

My understanding is:

PSB1
BBCA
horizontal max
C46 (674.0MHz) 576m 64QAM 8K 2/3
24.1Mb/s DVB-T MPEG2 100,000W
Channel icons
1 BBC One Scotland, 2 BBC Two Scotland, 7 BBC Three, 8 BBC Alba, 9 BBC
Four, 70 CBBC Channel, 71 CBeebies, 80 BBC News, 81 BBC Parliament,
301 BBC Red Button 1, plus 14 others

PSB2
D3+4
horizontal max
C43 (650.0MHz) 576m 64QAM 8K 2/3
24.1Mb/s DVB-T MPEG2 100,000W
Channel icons
3 STV (STV Central (Glasgow micro region)), 4 Channel 4 Scotland ads,
5 Channel 5 Scotland ads, 6 ITV 2, 13 Channel 4+1 Scotland ads, 14
More 4, 28 E4, 33 STV+1 (STV Edinburgh),

PSB3
BBCB
horizontal max
C40 (626.0MHz) 576m 256QAM 32KE 2/3
40.2Mb/s DVB-T2 MPEG4 100,000W
Channel icons
101 BBC One HD Scotland, 102 BBC Two HD (England), 103 STV HD (STV
West), 104 Channel 4 HD Scotland ads, 303 BBC Red Button HD, plus 1
others

COM4
SDN
horizontal max
C41+ (634.2MHz) 576m 64QAM 8K 3/4
27.1Mb/s DVB-T MPEG2 100,000W
Channel icons
10 ITV 3, 20 Drama, 25 Dave ja vu, 26 G.O.L.D. (not free), 27 ITV 2
+1, 30 5*, 31 5USA, 34 ESPN UK (not free), 38 Quest, 39 The Zone, 44
Channel 5 +1, 54 Home (not free), 72 CITV, plus 21 others

COM5
ArqA
horizontal max
C44 (658.0MHz) 576m 64QAM 8K 3/4
27.1Mb/s DVB-T MPEG2 100,000W
Channel icons
11 PICK TV, 12 Dave, 17 Really, 29 E4+1, 32 Movie Mix, 46 Challenge,
48 Food Network, 82 Sky News, 87 Community Channel, 302 BBC Red Button
2, plus 9 others

COM6
ArqB
horizontal max
C47 (682.0MHz) 576m 64QAM 8K 3/4
27.1Mb/s DVB-T MPEG2 100,000W
Channel icons
15 Film 4, 18 4Music, 19 Yesterday, 21 VIVA, 24 ITV 4, 41 Sky Sports 1
(not free), 42 Sky Sports 2 (not free), 47 4seven, 57 BT Sport (not
free), 58 BT Sport 1 (not free), 59 BT Sport 2 (not free), 83 Al
Jazeera English, 85 RT English , plus 22 others

Taken from http://www.ukfree.tv/txdetail.php?a=NS828647

"Scott" wrote in message
...
On Tue, 30 Jul 2013 17:04:35 +0100, "Woody"

wrote:

"Scott" wrote in message
. ..
On Sat, 27 Jul 2013 18:31:20 +0100, "R. Mark Clayton"
wrote:


"Scott" wrote in message
m...
On Sat, 20 Jul 2013 18:17:27 +0100, "R. Mark Clayton"
wrote:


"Scott" wrote in message
news:[email protected] com...
Following upon my previous posting, according to Brian
Butterworth's
site
http://www.ukfree.tv/fullstory.php?storyid=1107052119
the extra
frequences here will be 32 and 35. I understand Group B
aerials cover
channels 35 to 53. In the considered opinion of the
experts, am I
likely to require a new aerial or is 32 close enough to
35
to provide
an adequate albeit attenuated signal?

It will probably work the roll off is fairly shallow (but
will depend a
bit
on how many elements)

Looks like 11 elements (plus the reflector).

I could get a Group K aerial I suppose as my main concern
at
the time
was to try to minimise any 4G signals.

Put a filter on if it is actually a problem, far higher
selectivity than a
shortish aerial.

Thanks. I'm not expecting a problem. It's a high aerial
with
no base
stations nearby that I know about, pointing at a main
transmitter. The
highest channel number is 47 so I am optimistic at the
moment!



Er, the likelihood is that if the highest channel is 47 and it
has a full compliment of six muxes then those in the 40's are
for
the additional muxes and your core muxes (BBC, basic ITV and
HD)
will all be in the 20's and 30's. In that case a B-group may
not
be the best option. Six-mux transmitters in B-group all have
TX's
in the 50's.

My understanding is:

PSB1
BBCA
horizontal max
C46 (674.0MHz) 576m 64QAM 8K 2/3
24.1Mb/s DVB-T MPEG2 100,000W
Channel icons
1 BBC One Scotland, 2 BBC Two Scotland, 7 BBC Three, 8 BBC
Alba, 9 BBC
Four, 70 CBBC Channel, 71 CBeebies, 80 BBC News, 81 BBC
Parliament,
301 BBC Red Button 1, plus 14 others

PSB2
D3+4
horizontal max
C43 (650.0MHz) 576m 64QAM 8K 2/3
24.1Mb/s DVB-T MPEG2 100,000W
Channel icons
3 STV (STV Central (Glasgow micro region)), 4 Channel 4
Scotland ads,
5 Channel 5 Scotland ads, 6 ITV 2, 13 Channel 4+1 Scotland ads,
14
More 4, 28 E4, 33 STV+1 (STV Edinburgh),

PSB3
BBCB
horizontal max
C40 (626.0MHz) 576m 256QAM 32KE 2/3
40.2Mb/s DVB-T2 MPEG4 100,000W
Channel icons
101 BBC One HD Scotland, 102 BBC Two HD (England), 103 STV HD
(STV
West), 104 Channel 4 HD Scotland ads, 303 BBC Red Button HD,
plus 1
others

COM4
SDN
horizontal max
C41+ (634.2MHz) 576m 64QAM 8K 3/4
27.1Mb/s DVB-T MPEG2 100,000W
Channel icons
10 ITV 3, 20 Drama, 25 Dave ja vu, 26 G.O.L.D. (not free), 27
ITV 2
+1, 30 5*, 31 5USA, 34 ESPN UK (not free), 38 Quest, 39 The
Zone, 44
Channel 5 +1, 54 Home (not free), 72 CITV, plus 21 others

COM5
ArqA
horizontal max
C44 (658.0MHz) 576m 64QAM 8K 3/4
27.1Mb/s DVB-T MPEG2 100,000W
Channel icons
11 PICK TV, 12 Dave, 17 Really, 29 E4+1, 32 Movie Mix, 46
Challenge,
48 Food Network, 82 Sky News, 87 Community Channel, 302 BBC Red
Button
2, plus 9 others

COM6
ArqB
horizontal max
C47 (682.0MHz) 576m 64QAM 8K 3/4
27.1Mb/s DVB-T MPEG2 100,000W
Channel icons
15 Film 4, 18 4Music, 19 Yesterday, 21 VIVA, 24 ITV 4, 41 Sky
Sports 1
(not free), 42 Sky Sports 2 (not free), 47 4seven, 57 BT Sport
(not
free), 58 BT Sport 1 (not free), 59 BT Sport 2 (not free), 83
Al
Jazeera English, 85 RT English , plus 22 others

Taken from http://www.ukfree.tv/txdetail.php?a=NS828647




I stand corrected in this instance, although my comment does
indeed stand for most sites.


--
Woody

harrogate three at ntlworld dot com

On 30/07/2013 19:54, Woody wrote:
"Scott" wrote in message
...
On Tue, 30 Jul 2013 17:04:35 +0100, "Woody"

wrote:

"Scott" wrote in message
...
On Sat, 27 Jul 2013 18:31:20 +0100, "R. Mark Clayton"
wrote:


"Scott" wrote in message
...
On Sat, 20 Jul 2013 18:17:27 +0100, "R. Mark Clayton"
wrote:


"Scott" wrote in message
...
Following upon my previous posting, according to Brian
Butterworth's
site
http://www.ukfree.tv/fullstory.php?storyid=1107052119
the extra
frequences here will be 32 and 35. I understand Group B
aerials cover
channels 35 to 53. In the considered opinion of the
experts, am I
likely to require a new aerial or is 32 close enough to
35
to provide
an adequate albeit attenuated signal?

It will probably work the roll off is fairly shallow (but
will depend a
bit
on how many elements)

Looks like 11 elements (plus the reflector).

I could get a Group K aerial I suppose as my main concern
at
the time
was to try to minimise any 4G signals.

Put a filter on if it is actually a problem, far higher
selectivity than a
shortish aerial.

Thanks. I'm not expecting a problem. It's a high aerial
with
no base
stations nearby that I know about, pointing at a main
transmitter. The
highest channel number is 47 so I am optimistic at the
moment!



Er, the likelihood is that if the highest channel is 47 and it
has a full compliment of six muxes then those in the 40's are
for
the additional muxes and your core muxes (BBC, basic ITV and
HD)
will all be in the 20's and 30's. In that case a B-group may
not
be the best option. Six-mux transmitters in B-group all have
TX's
in the 50's.

My understanding is:

PSB1
BBCA
horizontal max
C46 (674.0MHz) 576m 64QAM 8K 2/3
24.1Mb/s DVB-T MPEG2 100,000W
Channel icons
1 BBC One Scotland, 2 BBC Two Scotland, 7 BBC Three, 8 BBC
Alba, 9 BBC
Four, 70 CBBC Channel, 71 CBeebies, 80 BBC News, 81 BBC
Parliament,
301 BBC Red Button 1, plus 14 others

PSB2
D3+4
horizontal max
C43 (650.0MHz) 576m 64QAM 8K 2/3
24.1Mb/s DVB-T MPEG2 100,000W
Channel icons
3 STV (STV Central (Glasgow micro region)), 4 Channel 4
Scotland ads,
5 Channel 5 Scotland ads, 6 ITV 2, 13 Channel 4+1 Scotland ads,
14
More 4, 28 E4, 33 STV+1 (STV Edinburgh),

PSB3
BBCB
horizontal max
C40 (626.0MHz) 576m 256QAM 32KE 2/3
40.2Mb/s DVB-T2 MPEG4 100,000W
Channel icons
101 BBC One HD Scotland, 102 BBC Two HD (England), 103 STV HD
(STV
West), 104 Channel 4 HD Scotland ads, 303 BBC Red Button HD,
plus 1
others

COM4
SDN
horizontal max
C41+ (634.2MHz) 576m 64QAM 8K 3/4
27.1Mb/s DVB-T MPEG2 100,000W
Channel icons
10 ITV 3, 20 Drama, 25 Dave ja vu, 26 G.O.L.D. (not free), 27
ITV 2
+1, 30 5*, 31 5USA, 34 ESPN UK (not free), 38 Quest, 39 The
Zone, 44
Channel 5 +1, 54 Home (not free), 72 CITV, plus 21 others

COM5
ArqA
horizontal max
C44 (658.0MHz) 576m 64QAM 8K 3/4
27.1Mb/s DVB-T MPEG2 100,000W
Channel icons
11 PICK TV, 12 Dave, 17 Really, 29 E4+1, 32 Movie Mix, 46
Challenge,
48 Food Network, 82 Sky News, 87 Community Channel, 302 BBC Red
Button
2, plus 9 others

COM6
ArqB
horizontal max
C47 (682.0MHz) 576m 64QAM 8K 3/4
27.1Mb/s DVB-T MPEG2 100,000W
Channel icons
15 Film 4, 18 4Music, 19 Yesterday, 21 VIVA, 24 ITV 4, 41 Sky
Sports 1
(not free), 42 Sky Sports 2 (not free), 47 4seven, 57 BT Sport
(not
free), 58 BT Sport 1 (not free), 59 BT Sport 2 (not free), 83
Al
Jazeera English, 85 RT English , plus 22 others

Taken from http://www.ukfree.tv/txdetail.php?a=NS828647




I stand corrected in this instance, although my comment does
indeed stand for most sites.



in fact, there is plans to launch com7 and com8 in the ch31 to ch38 band
at the 81 main transmitter sites..

your group B aerial may struggle to pick these up

On Tue, 30 Jul 2013 22:45:20 +0100, Stephen H
wrote:

On 30/07/2013 19:54, Woody wrote:
"Scott" wrote in message
...
On Tue, 30 Jul 2013 17:04:35 +0100, "Woody"

wrote:

"Scott" wrote in message
...
On Sat, 27 Jul 2013 18:31:20 +0100, "R. Mark Clayton"
wrote:


"Scott" wrote in message
...
On Sat, 20 Jul 2013 18:17:27 +0100, "R. Mark Clayton"
wrote:


"Scott" wrote in message
...
Following upon my previous posting, according to Brian
Butterworth's
site
http://www.ukfree.tv/fullstory.php?storyid=1107052119
the extra
frequences here will be 32 and 35. I understand Group B
aerials cover
channels 35 to 53. In the considered opinion of the
experts, am I
likely to require a new aerial or is 32 close enough to
35
to provide
an adequate albeit attenuated signal?

It will probably work the roll off is fairly shallow (but
will depend a
bit
on how many elements)

Looks like 11 elements (plus the reflector).

I could get a Group K aerial I suppose as my main concern
at
the time
was to try to minimise any 4G signals.

Put a filter on if it is actually a problem, far higher
selectivity than a
shortish aerial.

Thanks. I'm not expecting a problem. It's a high aerial
with
no base
stations nearby that I know about, pointing at a main
transmitter. The
highest channel number is 47 so I am optimistic at the
moment!



Er, the likelihood is that if the highest channel is 47 and it
has a full compliment of six muxes then those in the 40's are
for
the additional muxes and your core muxes (BBC, basic ITV and
HD)
will all be in the 20's and 30's. In that case a B-group may
not
be the best option. Six-mux transmitters in B-group all have
TX's
in the 50's.

My understanding is:

PSB1
BBCA
horizontal max
C46 (674.0MHz) 576m 64QAM 8K 2/3
24.1Mb/s DVB-T MPEG2 100,000W
Channel icons
1 BBC One Scotland, 2 BBC Two Scotland, 7 BBC Three, 8 BBC
Alba, 9 BBC
Four, 70 CBBC Channel, 71 CBeebies, 80 BBC News, 81 BBC
Parliament,
301 BBC Red Button 1, plus 14 others

PSB2
D3+4
horizontal max
C43 (650.0MHz) 576m 64QAM 8K 2/3
24.1Mb/s DVB-T MPEG2 100,000W
Channel icons
3 STV (STV Central (Glasgow micro region)), 4 Channel 4
Scotland ads,
5 Channel 5 Scotland ads, 6 ITV 2, 13 Channel 4+1 Scotland ads,
14
More 4, 28 E4, 33 STV+1 (STV Edinburgh),

PSB3
BBCB
horizontal max
C40 (626.0MHz) 576m 256QAM 32KE 2/3
40.2Mb/s DVB-T2 MPEG4 100,000W
Channel icons
101 BBC One HD Scotland, 102 BBC Two HD (England), 103 STV HD
(STV
West), 104 Channel 4 HD Scotland ads, 303 BBC Red Button HD,
plus 1
others

COM4
SDN
horizontal max
C41+ (634.2MHz) 576m 64QAM 8K 3/4
27.1Mb/s DVB-T MPEG2 100,000W
Channel icons
10 ITV 3, 20 Drama, 25 Dave ja vu, 26 G.O.L.D. (not free), 27
ITV 2
+1, 30 5*, 31 5USA, 34 ESPN UK (not free), 38 Quest, 39 The
Zone, 44
Channel 5 +1, 54 Home (not free), 72 CITV, plus 21 others

COM5
ArqA
horizontal max
C44 (658.0MHz) 576m 64QAM 8K 3/4
27.1Mb/s DVB-T MPEG2 100,000W
Channel icons
11 PICK TV, 12 Dave, 17 Really, 29 E4+1, 32 Movie Mix, 46
Challenge,
48 Food Network, 82 Sky News, 87 Community Channel, 302 BBC Red
Button
2, plus 9 others

COM6
ArqB
horizontal max
C47 (682.0MHz) 576m 64QAM 8K 3/4
27.1Mb/s DVB-T MPEG2 100,000W
Channel icons
15 Film 4, 18 4Music, 19 Yesterday, 21 VIVA, 24 ITV 4, 41 Sky
Sports 1
(not free), 42 Sky Sports 2 (not free), 47 4seven, 57 BT Sport
(not
free), 58 BT Sport 1 (not free), 59 BT Sport 2 (not free), 83
Al
Jazeera English, 85 RT English , plus 22 others

Taken from http://www.ukfree.tv/txdetail.php?a=NS828647




I stand corrected in this instance, although my comment does
indeed stand for most sites.



in fact, there is plans to launch com7 and com8 in the ch31 to ch38 band
at the 81 main transmitter sites..

your group B aerial may struggle to pick these up

That was the original question at the start of the thread :-)