jaycar uhf aerial problem
 

I am in Australia and have just bought
a Jaycar 91 element UHF TV aerial.

It is supposed to cover frequencies from 470 to 862 MHz.
I want to use it for Digital TV reception.

http://www1.jaycar.com.au/productVie...=&SUBCATID=478

The aerial is in kit form
and main beam comes in three sections.

The cryptic instruction sheet does not say which way round
the centre of the three sections should go and there are
no indicating marks either.

Depending on which way you have it the spacing of the
elements in the centre section will change in relation to
elements in the other two sections.

Is this a problem?

Is there a way to check for the correct orientation
other than trying it both ways?

Thanks in advance,
Greg.

well, there should be some logical progression from front to back on the
antenna. normally the elements get larger as you go from the front to the
back of the antenna. if you can't sort it out from the instructions,
picture on the web or in the instruction book, then try calling their
support line and ask.

"gregB" wrote in message
...
I am in Australia and have just bought
a Jaycar 91 element UHF TV aerial.

It is supposed to cover frequencies from 470 to 862 MHz.
I want to use it for Digital TV reception.

http://www1.jaycar.com.au/productVie...=&SUBCATID=478

The aerial is in kit form
and main beam comes in three sections.

The cryptic instruction sheet does not say which way round
the centre of the three sections should go and there are
no indicating marks either.

Depending on which way you have it the spacing of the
elements in the centre section will change in relation to
elements in the other two sections.

Is this a problem?

Is there a way to check for the correct orientation
other than trying it both ways?

Thanks in advance,
Greg.

Dave, thanks for the reply.
The spacing does generally increase but not
progressively.
Some intervals are a few centimeters less than the previous one.
Greg.




Dave wrote:
well, there should be some logical progression from front to back on the
antenna. normally the elements get larger as you go from the front to the
back of the antenna. if you can't sort it out from the instructions,
picture on the web or in the instruction book, then try calling their
support line and ask.

"gregB" wrote in message
...

I am in Australia and have just bought
a Jaycar 91 element UHF TV aerial.

It is supposed to cover frequencies from 470 to 862 MHz.
I want to use it for Digital TV reception.

http://www1.jaycar.com.au/productVie...=&SUBCATID=478

The aerial is in kit form
and main beam comes in three sections.

The cryptic instruction sheet does not say which way round
the centre of the three sections should go and there are
no indicating marks either.

Depending on which way you have it the spacing of the
elements in the centre section will change in relation to
elements in the other two sections.

Is this a problem?

Is there a way to check for the correct orientation
other than trying it both ways?

Thanks in advance,
Greg.

The picture on the web site shows exactly how the center section should be.

"gregB" wrote in message
...
I am in Australia and have just bought
a Jaycar 91 element UHF TV aerial.

It is supposed to cover frequencies from 470 to 862 MHz.
I want to use it for Digital TV reception.


http://www1.jaycar.com.au/productVie...=&SUBCATID=478

The aerial is in kit form
and main beam comes in three sections.

The cryptic instruction sheet does not say which way round
the centre of the three sections should go and there are
no indicating marks either.

Depending on which way you have it the spacing of the
elements in the centre section will change in relation to
elements in the other two sections.

Is this a problem?

Is there a way to check for the correct orientation
other than trying it both ways?

Thanks in advance,
Greg.

Fred, thanks for the reply.

Yes, the photo does show a longer interval at the
left end and is probably correct.

I think this is helped by the perspective of the photo.
On the ground both orientations look plausible.

Also this assumes it was put together correctly
and not at random buy the advertising department.

I was really hoping there might be a formula for
working out the element spacing.

Regards,
Greg.



Fred W4JLE wrote:
The picture on the web site shows exactly how the center section should be.

"gregB" wrote in message
...

I am in Australia and have just bought
a Jaycar 91 element UHF TV aerial.

It is supposed to cover frequencies from 470 to 862 MHz.
I want to use it for Digital TV reception.



http://www1.jaycar.com.au/productVie...=&SUBCATID=478

The aerial is in kit form
and main beam comes in three sections.

The cryptic instruction sheet does not say which way round
the centre of the three sections should go and there are
no indicating marks either.

Depending on which way you have it the spacing of the
elements in the centre section will change in relation to
elements in the other two sections.

Is this a problem?

Is there a way to check for the correct orientation
other than trying it both ways?

Thanks in advance,
Greg.