Antiference XG16CD alternative?

"Jonathan Buzzard" wrote in message
...
Well the system is based around a Antiference ISYS7. I would have
preferred something with less outputs as 12 is overkill,
The outputs fail one at a time so a few spare is good.

but I could find
nothing else that took a quattro LNB, UHF, FM and DAB and then spit it all
out on one download, had a built in mains supply and provided 12V for the
masthead amplifier. I figure it will pay for itself as I have to run far
fewer downleads as I do the house up :-)
Bit of a batch fault with these some time ago. If the terr gain was at max
the amp went funny and the noise was quite bad. Back it off 2dB and it's OK.


Where does a DIY'er get channel filters?
Asd long as you know what you want, Taylor Bros. Download their catalogue
(Taylor Transmitters). Or Polytron in Germany.


Another question is the manual for the ISYS7 says I should terminate any
unused outputs. Can I just solder a 75 Ohm resistor to a F plug, are there
pre-made jobs I can buy?
Dunno why they say that. I wouldn't bother. But yes, you can buy 'f'
terminators from such as CPC.

Bill

Well the system is based around a Antiference ISYS7. I would have
preferred something with less outputs as 12 is overkill, but I could find
nothing else that took a quattro LNB, UHF, FM and DAB and then spit it all
out on one download, had a built in mains supply and provided 12V for the
masthead amplifier. I figure it will pay for itself as I have to run far
fewer downleads as I do the house up :-)

Where does a DIY'er get channel filters?

Direct from Taylor Bros.
I have a pair of TCFL-5s in front of my ISYS-7.

http://www.lowe-family.me.uk/d-i-y/HeadEnd.JPG

One is tuned to the analog channels, ond one for the digital muxes.
( Mine's on Durris. )
Just tell them the TX, and they'll set up the channels for you.
They're re-combined with a TCLM 2-A, but you could use a simple passive
device.
Note that a lot of the Taylor kit used threaded Belling-Lee UHF connectors,
so order up the necessary adaptors at the same time, if you want to use
f-connectors, as per the photo ( or use UHF plugs on the cables ).

Beware!
The filters ( or perhaps the TCLM 2A ) present a short-circuit to the 12v
masthead-amp supply from the ISYS-7. The 'Auto Line Power' LED will go
out, and the PSU will get hot! You need to put the DC-blocking capacitor
in-line with the UHF input, as shown on my photo. ( It's supplied with the
ISYS unit. )

Another question is the manual for the ISYS7 says I should terminate any
unused outputs. Can I just solder a 75 Ohm resistor to a F plug, are there
pre-made jobs I can buy?


I didn't bother, all seems OK.

--
Ron

On Tue, 04 Nov 2008 19:13:52 +0000, Marky P wrote:

On Mon, 3 Nov 2008 21:43:01 +0000, Jonathan Buzzard
wrote:

On Mon, 03 Nov 2008 02:15:11 +0000, Bill Wright wrote:

"Jonathan Buzzard" wrote in message
...
The problem with this is Durris has all it's transmissions at lower
frequencies than Angus, and on all set top boxes I have tried, when one
does a scan it picks up weak signals from the Durris transmitter and
ignores the much stronger (and perfectly usable) signals from the Angus
transmitter.

A Gp CD aerial would still pick up enough GpA and GpB signals to cause this
problem. Yagis are inherently quite good on frequencies just below their
design range.


True, but the signal from the wideband is er rubbish to say the least. I
expect that with this one needing to point a further 10 degrees away from
Durris and a proper C/D aerial, it would not suffer the same problem as
the DAT75 with MRD the last installation I did does (for my godmother).

Many receivers allow 'auto retune off'.

Any many don't, so I want a "pro" solution that does not suffer this
problem :-)


JAB.

Check out the Blake range. They do some large grouped arrays and
their performance is excellent.


Hum, none of which has the gain of the XG16CD, in fact a several dB lower :-(


JAB.

--
Jonathan A. Buzzard Email: jonathan (at) buzzard.me.uk
Fife, United Kingdom.

On Wed, 05 Nov 2008 04:16:27 +0000, Bill Wright wrote:

"Jonathan Buzzard" wrote in message
...
Well the system is based around a Antiference ISYS7. I would have
preferred something with less outputs as 12 is overkill,
The outputs fail one at a time so a few spare is good.


That does not sound good.

but I could find
nothing else that took a quattro LNB, UHF, FM and DAB and then spit it all
out on one download, had a built in mains supply and provided 12V for the
masthead amplifier. I figure it will pay for itself as I have to run far
fewer downleads as I do the house up :-)
Bit of a batch fault with these some time ago. If the terr gain was at max
the amp went funny and the noise was quite bad. Back it off 2dB and it's OK.


Thanks for the tip, will do.


Where does a DIY'er get channel filters?
Asd long as you know what you want, Taylor Bros. Download their catalogue
(Taylor Transmitters). Or Polytron in Germany.


I think I may have found a source of the XG16CD so I will try it without
filters first, and if that gives satisfactory results skip them. I could
get away with far less if I was not shooting for a loft mount. However the
North Sea is only 500m away, and looking round the neighbour hood, most of
the aerials are in poor condition.


Another question is the manual for the ISYS7 says I should terminate any
unused outputs. Can I just solder a 75 Ohm resistor to a F plug, are there
pre-made jobs I can buy?
Dunno why they say that. I wouldn't bother. But yes, you can buy 'f'
terminators from such as CPC.


I guess it is something to do with the output amplifier circuit not being
happy if it does not have a load to dump the output into. I can imagine it
stresses the amp and over time bad things happen. As CPC sell a pack of 10
for under two quid, I will put some on my next order.

What's your thoughts on crimped versus twist on F connectors? Is it worth
borrowing the crimp tool from work or are twist on just as good?


JAB.

--
Jonathan A. Buzzard Email: jonathan (at) buzzard.me.uk
Fife, United Kingdom.

"Jonathan Buzzard" wrote in message
...
On Wed, 05 Nov 2008 04:16:27 +0000, Bill Wright wrote:

"Jonathan Buzzard" wrote in message
...
Well the system is based around a Antiference ISYS7. I would have
preferred something with less outputs as 12 is overkill,
The outputs fail one at a time so a few spare is good.


That does not sound good.

All multiswitches are the same in this respect.

I think I may have found a source of the XG16CD so I will try it without
filters first, and if that gives satisfactory results skip them. I could
get away with far less if I was not shooting for a loft mount.
Oh well, if you put a big high gain aerial in the loft the performance will
be reduced.

However the
North Sea is only 500m away, and looking round the neighbour hood, most of
the aerials are in poor condition.
Oh, make life easy and put the bloody thing on the roof where it belongs. By
the time it rots away you will probably be dead. Stop worrying. Honestly Gp
CD in a loft is bad news. An XG16 in the loft won't work as well as a 10
element on the roof.

I guess it is something to do with the output amplifier circuit not being
happy if it does not have a load to dump the output into. I can imagine it
stresses the amp and over time bad things happen.
Your hypothesis is probably correct in theory. But I'm telling you from
having installed God knows how many of the things that it makes not a scrap
of difference. I've actually left them powered up with only 2 out of 12
outputs connected for a year pending later phases of work and they have
survived. The sat outputs are internally switched so termination can't have
any effect on the amps that drive them. The terr output no doubt works via a
deliberately inefficient splitting network that will provide the necessary
degree of RF isolation between ports. In any case a 12 way split can't
return much from each port to the amp can it? So in reality I doubt if any
VSWR situation could bother the amp.

As CPC sell a pack of 10
for under two quid, I will put some on my next order.
OK. Look closely at the centre pin as you insert them. It is very thin and
sometimes bends to one side and doesn't go in the hole. Years ago I had a
batch from CPC that didn't have any resistors or pins!


What's your thoughts on crimped versus twist on F connectors? Is it worth
borrowing the crimp tool from work or are twist on just as good?
Oh, I should use the twist on. You need to get the right size though. The
Antiference ones are a good fit on CT100 or QF100 or QC100.

Bill

In article , Jonathan Buzzard
scribeth thus
On Tue, 04 Nov 2008 19:13:52 +0000, Marky P wrote:

On Mon, 3 Nov 2008 21:43:01 +0000, Jonathan Buzzard
wrote:

On Mon, 03 Nov 2008 02:15:11 +0000, Bill Wright wrote:

"Jonathan Buzzard" wrote in message
...
The problem with this is Durris has all it's transmissions at lower
frequencies than Angus, and on all set top boxes I have tried, when one
does a scan it picks up weak signals from the Durris transmitter and
ignores the much stronger (and perfectly usable) signals from the Angus
transmitter.

A Gp CD aerial would still pick up enough GpA and GpB signals to cause this
problem. Yagis are inherently quite good on frequencies just below their
design range.


True, but the signal from the wideband is er rubbish to say the least. I
expect that with this one needing to point a further 10 degrees away from
Durris and a proper C/D aerial, it would not suffer the same problem as
the DAT75 with MRD the last installation I did does (for my godmother).

Many receivers allow 'auto retune off'.

Any many don't, so I want a "pro" solution that does not suffer this
problem :-)


JAB.

Check out the Blake range. They do some large grouped arrays and
their performance is excellent.


Hum, none of which has the gain of the XG16CD, in fact a several dB lower :-(



Got any response curves for those then?..

--
Tony Sayer

On Fri, 7 Nov 2008 00:12:52 +0000, Jonathan Buzzard
wrote:

On Tue, 04 Nov 2008 19:13:52 +0000, Marky P wrote:

On Mon, 3 Nov 2008 21:43:01 +0000, Jonathan Buzzard
wrote:

On Mon, 03 Nov 2008 02:15:11 +0000, Bill Wright wrote:

"Jonathan Buzzard" wrote in message
...
The problem with this is Durris has all it's transmissions at lower
frequencies than Angus, and on all set top boxes I have tried, when one
does a scan it picks up weak signals from the Durris transmitter and
ignores the much stronger (and perfectly usable) signals from the Angus
transmitter.

A Gp CD aerial would still pick up enough GpA and GpB signals to cause this
problem. Yagis are inherently quite good on frequencies just below their
design range.


True, but the signal from the wideband is er rubbish to say the least. I
expect that with this one needing to point a further 10 degrees away from
Durris and a proper C/D aerial, it would not suffer the same problem as
the DAT75 with MRD the last installation I did does (for my godmother).

Many receivers allow 'auto retune off'.

Any many don't, so I want a "pro" solution that does not suffer this
problem :-)


JAB.

Check out the Blake range. They do some large grouped arrays and
their performance is excellent.


Hum, none of which has the gain of the XG16CD, in fact a several dB lower :-(


JAB.

Beware of published figures. I replaced a DAT45 with a Blake SR18
with tremendous improvements despite the higher gain figures claimed
by the DAT45.

Marky P.

"tony sayer" wrote in message
...
In article , Jonathan Buzzard
Check out the Blake range. They do some large grouped arrays and
their performance is excellent.


Hum, none of which has the gain of the XG16CD, in fact a several dB lower
:-(



Got any response curves for those then?..

I don't take any notice of manufacturers' figures. There are too many
variables -- it's just too easy to fudge. I test one aerial against another
from time to time, and draw my own conclusions.

Then of course there's my mV per kilo theory:

If you were to compare the amount of signal at the terminals of aerials of
various designs with the weight of each aerial, you would obtain a mV per
kilo figure. This figure would be highest for the smallest aerials, such as
the half wave dipole, and lowest for the latest Superbo Antennisimo
Fantastico Gereralisimo Grandioso with 164 elements and a built-in microvolt
maximiser.

Bill

"Marky P" wrote in message
...
Beware of published figures. I replaced a DAT45 with a Blake SR18
with tremendous improvements despite the higher gain figures claimed
by the DAT45.

After several years of deliberation I finally decided that I couldn't be
doing with the various physical failings of Antiference aerials, so after
much testing I've started using SR18s. They perform just as well as
Antiference.

Bill

In article , Bill Wright
scribeth thus

"tony sayer" wrote in message
...
In article , Jonathan Buzzard
Check out the Blake range. They do some large grouped arrays and
their performance is excellent.


Hum, none of which has the gain of the XG16CD, in fact a several dB lower
:-(



Got any response curves for those then?..

I don't take any notice of manufacturers' figures. There are too many
variables -- it's just too easy to fudge. I test one aerial against another
from time to time, and draw my own conclusions.


A point made very well...

Then of course there's my mV per kilo theory:

If you were to compare the amount of signal at the terminals of aerials of
various designs with the weight of each aerial, you would obtain a mV per
kilo figure. This figure would be highest for the smallest aerials, such as
the half wave dipole, and lowest for the latest Superbo Antennisimo
Fantastico Gereralisimo Grandioso with 164 elements and a built-in microvolt
maximiser.

Bill



--
Tony Sayer