dipole extension?
 

Hoping someone might have a idea as to what's best in this situation...


My set up

a sgc237 tuner at bottom of a (center support) 5' pvc mast, feeding 5'
450ohm ladder line to a horizontal center fd dipole


Issue:
unfortunately i don 't have too much horizantal roof space seems i'll
have about 40ft on one side maybe 20ft on the other

the ends will be supported by tv mast and clamped onto the sewer (cast
iron?) vent pipe on each far end

The far end masts are 10ft tall (making entire dipole 20ft off roof
surface)

3 questions:

a) would it be better just to leave the dipole as is horizonal(and
kinda short for multiband dreams) or

b) extend it by adding a 10ft verticle wire along the mast (using
plastic spacers?)drooping down

c)attach my dipole to the mast making it part of the dipole (this
presumes the cast iron sewer pipe makes too poor a connection to matter
i don't know , suppose i can rap it w/duct tape)

In the continuing saga of the 12 or 14 story roof antenna,
"ml" wrote

Hoping someone might have a idea as to what's best in this situation...


My set up

a sgc237 tuner at bottom of a (center support) 5' pvc mast, feeding 5'
450ohm ladder line to a horizontal center fd dipole


Issue:
unfortunately i don 't have too much horizantal roof space seems i'll
have about 40ft on one side maybe 20ft on the other

the ends will be supported by tv mast and clamped onto the sewer (cast
iron?) vent pipe on each far end

The far end masts are 10ft tall (making entire dipole 20ft off roof
surface)

3 questions:

a) would it be better just to leave the dipole as is horizonal(and
kinda short for multiband dreams) or

b) extend it by adding a 10ft verticle wire along the mast (using
plastic spacers?)drooping down

c)attach my dipole to the mast making it part of the dipole (this
presumes the cast iron sewer pipe makes too poor a connection to matter
i don't know , suppose i can rap it w/duct tape)

Recall from previous replies that:

1. Cast iron roof vents are supported by and grounded to building structural
steel. They will probably not be a good choice to terminate an antenna right
next to. Then again you could be improving SWL reception in all the
lavatories of the building ;-)

2. The building's t.v. antenna (and thus tenant's televisions) is may be a
pretty good receiver for anything you transmit right next to it. Using the
t.v. mast as part of your antenna? I would stay as far away from it as
possible.

Why don't you consider one of those toaster-oven (Isotrons?)? At your high
elevation they probably work as well a their design ever allows. For at
least 23 hams who made the reviews on eHam, the things do work at least
marginally well, and take up practically no space at all. Just my 2 cents,
since a dipole seems such a challenge for your conditions.

73,
Jack Painter
Virginia Beach, Virginia

thanks for the responce

by tv mast i ment tv style 1 1/4" pipe not the actual mast with the
building antenna

the isotron was a interesting idea but a dipole is what i will have to
surfice with it's not much of a challange, but some of the 'details'
are a bit more difficult than thought

i do hope someone will be able o answer the questions i posted (other
than your reply to "c" being n/g)

tnx


In article QOwSd.59$7z6.41@lakeread04,
"Jack Painter" wrote:

In the continuing saga of the 12 or 14 story roof antenna,
"ml" wrote

Hoping someone might have a idea as to what's best in this situation...


My set up

a sgc237 tuner at bottom of a (center support) 5' pvc mast, feeding 5'
450ohm ladder line to a horizontal center fd dipole


Issue:
unfortunately i don 't have too much horizantal roof space seems i'll
have about 40ft on one side maybe 20ft on the other

the ends will be supported by tv mast and clamped onto the sewer (cast
iron?) vent pipe on each far end

The far end masts are 10ft tall (making entire dipole 20ft off roof
surface)

3 questions:

a) would it be better just to leave the dipole as is horizonal(and
kinda short for multiband dreams) or

b) extend it by adding a 10ft verticle wire along the mast (using
plastic spacers?)drooping down

c)attach my dipole to the mast making it part of the dipole (this
presumes the cast iron sewer pipe makes too poor a connection to matter
i don't know , suppose i can rap it w/duct tape)

Recall from previous replies that:

1. Cast iron roof vents are supported by and grounded to building structural
steel. They will probably not be a good choice to terminate an antenna right
next to. Then again you could be improving SWL reception in all the
lavatories of the building ;-)

2. The building's t.v. antenna (and thus tenant's televisions) is may be a
pretty good receiver for anything you transmit right next to it. Using the
t.v. mast as part of your antenna? I would stay as far away from it as
possible.

Why don't you consider one of those toaster-oven (Isotrons?)? At your high
elevation they probably work as well a their design ever allows. For at
least 23 hams who made the reviews on eHam, the things do work at least
marginally well, and take up practically no space at all. Just my 2 cents,
since a dipole seems such a challenge for your conditions.

73,
Jack Painter
Virginia Beach, Virginia