Digital TV - DIY articles

On Wed, 4 Mar 2009 22:46:43 -0000 someone who may be "Graham."
wrote this:-

Justin has a good website but he seems to think logs are new.
"The Log Periodic is a fairly recent development"
http://www.aerialsandtv.com/aerials.html

I suppose that depends on what he means by fairly recent and in what
field he is talking about. Assuming he is talking about them being a
fairly recent development for domestic television reception would
anyone take issue with him?

As I recall my reading they were developed in the late forties or
early fifties by navies, who wanted to reduce the clutter of aerials
for various radio frequencies with one broadband aerial. There are
photographs of ships with very large versions. This was 20-30 years
after Mr Yagi's patent.

Navies have come up with all sorts of space saving broadband
aerials, though they might not look so good on houses.



--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

Alan Pemberton wrote:
J G Miller wrote:

You are totally missing the point I was trying to make.

If any of the CAI approved antennas are log periodics, then the
statement that all CAI approved antennas have baluns is erroneous.

I seem to be totally missing the point as well. To feed a log periodic
you have to shove the coax up one of the tubes and connect it to the
front ends of both. That forms a balun. Who is it that is going around
saying log periodics don't have baluns?

I think the suggestion is that it is far less readily apparent on a log
since there is not usually a separate transformer etc.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
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| John Rumm - john(at)internode(dot)co(dot)uk |
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"David Hansen" wrote in message
...
On Wed, 4 Mar 2009 22:46:43 -0000 someone who may be "Graham."
wrote this:-

Justin has a good website but he seems to think logs are new.
"The Log Periodic is a fairly recent development"
http://www.aerialsandtv.com/aerials.html

I suppose that depends on what he means by fairly recent and in what
field he is talking about. Assuming he is talking about them being a
fairly recent development for domestic television reception would
anyone take issue with him?

Yes I would. See this aerial, installed 35 years ago.

Bill

In article ,
David Hansen wrote:
On Wed, 4 Mar 2009 22:46:43 -0000 someone who may be "Graham."
wrote this:-

Justin has a good website but he seems to think logs are new.
"The Log Periodic is a fairly recent development"
http://www.aerialsandtv.com/aerials.html

I suppose that depends on what he means by fairly recent and in what
field he is talking about. Assuming he is talking about them being a
fairly recent development for domestic television reception would
anyone take issue with him?

The BBC took the original short wave version and redesigned it for uhf
reception.

JBeam were selling domestic ones in the 70's and there was also a "TopLog"
(set top one) sold by Labgear around the same time.


As I recall my reading they were developed in the late forties or
early fifties by navies, who wanted to reduce the clutter of aerials
for various radio frequencies with one broadband aerial. There are
photographs of ships with very large versions. This was 20-30 years
after Mr Yagi's patent.

The WRTvH sometimes had an advert for a Swedish short wave one where the
smallest element appeared to be about 1ft in diameter. Designed for
broadcasting. They were also fairly common of the roof tops of London
embassies before the days of satellites.

Navies have come up with all sorts of space saving broadband
aerials, though they might not look so good on houses.

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11

In article ,
David Hansen wrote:
On Wed, 4 Mar 2009 22:46:43 -0000 someone who may be "Graham."
wrote this:-

Justin has a good website but he seems to think logs are new.
"The Log Periodic is a fairly recent development"
http://www.aerialsandtv.com/aerials.html

I suppose that depends on what he means by fairly recent and in what
field he is talking about. Assuming he is talking about them being a
fairly recent development for domestic television reception would
anyone take issue with him?

They were around for domestic use when UHF broadcasting started in the UK.
Although rarely used due to cost.
I used one for my first colour TV - just after BBC1 and ITV went colour.

--
*How come you never hear about gruntled employees? *

Dave Plowman London SW
To e-mail, change noise into sound.

Justin has a good website but he seems to think logs are new.
"The Log Periodic is a fairly recent development"
http://www.aerialsandtv.com/aerials.html

I suppose that depends on what he means by fairly recent and in what
field he is talking about. Assuming he is talking about them being a
fairly recent development for domestic television reception would
anyone take issue with him?

Yes I would. See this aerial, installed 35 years ago.

I can't see it, must be too far away :-)

From my point of view, as a long time observer of aerials
rather than a rigger, LPs were commonly seen in the 70s
and early 80s along with various "grid " type arrays as a means
of combating ghosting.
Then they went out of fashion for some reason, now they are
making a comeback and are even promoted as the aerial
of choice for normal good reception situations, which was
never previously the case.
Just to clarify I am talking about UHF TV reception here.

Would you agree with any of that Bill?

--
Graham.

%Profound_observation%

Bill Wright wrote:

I suppose that depends on what he means by fairly recent and in what
field he is talking about. Assuming he is talking about them being a
fairly recent development for domestic television reception would
anyone take issue with him?

Yes I would. See this aerial, installed 35 years ago.

Log aperiodic aerials were common even back in the days of 405 line TV.
Maybe those in towns and cities never saw them, but out in outlying
areas it was common to see some military sized monsters in farmyards.

On Sat, 07 Mar 2009 14:59:01 +0000, David Hansen wrote:

On Wed, 4 Mar 2009 23:48:12 -0000 someone who may be "Graham."
wrote this:-

One option we have not listed is "other" digital satellite options...
Anyone have any comments on what is out there for people who buy generic
non sky and non freesat boxes?

I wouldn't recommend one for normal Astra 2 reception because there would
be no EPG

Fortec Star have had a seven day electronic programme guide on their
receivers for some months. I understand that they have reverse
engineered the Freesat data.

Interesting - how do I get that? I've a Fortec Lifetime box receiving Astra
2, but I'm not sure that it's Freeview as such.
--
Peter.
You don't understand Newton's Third Law of Motion?
It's not rocket science, you know.

Dave Plowman (News) wrote:

In article ,
David Hansen wrote:
On Wed, 4 Mar 2009 22:46:43 -0000 someone who may be "Graham."
wrote this:-

Justin has a good website but he seems to think logs are new.
"The Log Periodic is a fairly recent development"
http://www.aerialsandtv.com/aerials.html

I suppose that depends on what he means by fairly recent and in what
field he is talking about. Assuming he is talking about them being a
fairly recent development for domestic television reception would
anyone take issue with him?

They were around for domestic use when UHF broadcasting started in the UK.
Although rarely used due to cost.
I used one for my first colour TV - just after BBC1 and ITV went colour.

Before that. Log-aperiodic aerials were available for VHF TV reception
from the mid 50s onwards but because of their huge size were only seen
in fringe reception areas. My father had a bee in his bonnet about being
able to receive TV from Emley Moor so we had a steerable VHF monster
fitted to the house back in 1967, that was the first time I recall
anyone mentioning a log-aperiodic aerial. UHF TV didn't reach our
backwater until the late 1970s.

"Graham." wrote in message
...
From my point of view, as a long time observer of aerials
rather than a rigger, LPs were commonly seen in the 70s
and early 80s along with various "grid " type arrays as a means
of combating ghosting.
Then they went out of fashion for some reason, now they are
making a comeback and are even promoted as the aerial
of choice for normal good reception situations, which was
never previously the case.
Just to clarify I am talking about UHF TV reception here.

Would you agree with any of that Bill?

Yes, all of it.

Bill