I am setting up a base station at my house. I will have a 440 mhz yagi
and a 2 meter ground plane antenna. I am trying to figure out how to
mount these on my roof. At the end of the house where my chimney is
would be perfect. It is a wood and viynle chimney, not brick. It is not
used. (No fires or gas logs.)

Would it be two much to mount a mast and two antennas on this?
I sometimes get high winds in the summer during thunder storms.

wrote:
I am setting up a base station at my house. I will have a 440 mhz yagi
and a 2 meter ground plane antenna. I am trying to figure out how to
mount these on my roof. At the end of the house where my chimney is
would be perfect. It is a wood and viynle chimney, not brick. It is
not used. (No fires or gas logs.)

Would it be two much to mount a mast and two antennas on this?
I sometimes get high winds in the summer during thunder storms.

Assuming that the UHF yagi is a single yagi and not a big, rotatable array
you shouldn't have any problems with wind loading. Just use a wrap-around
chimney mount and a 10 foot mast. You can even get these at *ugh*
RadioShark.

http://www.radioshack.com/product.as...%5Fid=15%2D839

Travis Jordan wrote:
wrote:
I am setting up a base station at my house. I will have a 440 mhz
yagi
and a 2 meter ground plane antenna. I am trying to figure out how
to
mount these on my roof. At the end of the house where my chimney is
would be perfect. It is a wood and viynle chimney, not brick. It is
not used. (No fires or gas logs.)

Would it be two much to mount a mast and two antennas on this?
I sometimes get high winds in the summer during thunder storms.

Assuming that the UHF yagi is a single yagi and not a big, rotatable
array
you shouldn't have any problems with wind loading. Just use a
wrap-around
chimney mount and a 10 foot mast. You can even get these at *ugh*
RadioShark.


http://www.radioshack.com/product.as...%5Fid=15%2D839


Even with two antennas on it? The two meter also? I have to soemhowe
keep these antennas at least 6 feet apart too.

wrote:
Travis Jordan wrote:
wrote:
I am setting up a base station at my house. I will have a 440 mhz
yagi and a 2 meter ground plane antenna. I am trying to figure
out how to mount these on my roof. At the end of the house where
my chimney is would be perfect. It is a wood and viynle chimney,
not brick. It is not used. (No fires or gas logs.)

Would it be two much to mount a mast and two antennas on this?
I sometimes get high winds in the summer during thunder storms.

Assuming that the UHF yagi is a single yagi and not a big,
rotatable array you shouldn't have any problems with wind loading.
Just use a wrap-around chimney mount and a 10 foot mast. You can
even get these at *ugh* RadioShark.



http://www.radioshack.com/product.as...%5Fid=15%2D839


Even with two antennas on it? The two meter also? I have to soemhowe
keep these antennas at least 6 feet apart too.

Mount the ground plane on the top and the yagi just above the chimney. You
don't need 6' of separation with them mounted vertically. There is good
isolation below the ground plane due to the antenna pattern.

How is the best way to go about grounding the hole thing?

wrote:
How is the best way to go about grounding the hole thing?
Run at least one #8 or larger aluminum or copper wire from a bolt on the
mast or its base down to a 8' or deeper ground rod.

Travis Jordan wrote:
wrote:

How is the best way to go about grounding the hole thing?

Run at least one #8 or larger aluminum or copper wire from a bolt on the
mast or its base down to a 8' or deeper ground rod.


You left off a step.
and then bond that ground rod to the rest of the houses grounding
electrode system using copper number six or larger conductor.
--
Tom H

HorneTD wrote:
Travis Jordan wrote:
wrote:

How is the best way to go about grounding the hole thing?

Run at least one #8 or larger aluminum or copper wire from a bolt
on the mast or its base down to a 8' or deeper ground rod.


You left off a step.
and then bond that ground rod to the rest of the houses grounding
electrode system using copper number six or larger conductor.

True! NEC requires it.

Travis Jordan wrote:
HorneTD wrote:
Travis Jordan wrote:
wrote:

How is the best way to go about grounding the hole thing?

Run at least one #8 or larger aluminum or copper wire from a bolt
on the mast or its base down to a 8' or deeper ground rod.


You left off a step.
and then bond that ground rod to the rest of the houses grounding
electrode system using copper number six or larger conductor.

True! NEC requires it.

A couple of good articles on the subject for the OP:
http://www.polyphaser.com/ppc_PEN1016.asp
http://www.polyphaser.com/ppc_PEN1025.asp

HorneTD wrote:
Travis Jordan wrote:
wrote:

How is the best way to go about grounding the hole thing?

Run at least one #8 or larger aluminum or copper wire from a bolt
on the
mast or its base down to a 8' or deeper ground rod.


You left off a step.
and then bond that ground rod to the rest of the houses grounding
electrode system using copper number six or larger conductor.
--
Tom H

My TV antenna has its own ground rod that the tower is grounded to.

Are you saying I need to run a wire from the house ground to the ground
rod? How do I do that?

wrote:
HorneTD wrote:

Travis Jordan wrote:

wrote:


How is the best way to go about grounding the hole thing?

Run at least one #8 or larger aluminum or copper wire from a bolt

on the

mast or its base down to a 8' or deeper ground rod.



You left off a step.
and then bond that ground rod to the rest of the houses grounding
electrode system using copper number six or larger conductor.
--
Tom H


My TV antenna has its own ground rod that the tower is grounded to.

Are you saying I need to run a wire from the house ground to the ground
rod? How do I do that?


If the tower is a free standing structure that is not attached to the
building except by it's antenna lead in then you do not have to bond the
two electrodes to each other. If the tower is attached to or supported
by the structure than the two grounding electrodes should be bonded
together to behave as a single grounding electrode system.

The last thing you want is a lightning strike flashing over between two
electrically isolated systems such as between the tower structure and
the wiring system in an adjacent wall. Use of a common grounding
electrode system will assure that as the voltage of one system goes high
that the voltage of the other system will be the same thus avoiding the
voltage difference that will cause destructive current flow.

In either case the antenna lead in should be fitted with a suitable
lightning arrester and a transient voltage surge suppressor at the point
were these systems enter the structure. Systems within the same
building must all use the same grounding electrode system or the
inevitable voltage gradient between the two systems will cause damage to
any equipment that is connected to services that use the two different
systems. TVs, answering and fax machines, computers that are equipped
with a modem or network card, and any other device that has a connection
to more than one wire born utility will be damaged when any surge or
spike equalizes through the equipment instead of through appropriately
sized bonding conductors.
--
Tom H