DIY Omni TV receiver antenna challenge
 

I wish to hoist an antenna up a sailboat mast on a halyard to help
receive TV stations when out in the Chesapeake Bay. The challenge is
that the boat will rotate at anchor with the wind and even turn the
antanna on it's axis as it it "hoisted" by rope and not locked
rotationally.

There are commercially available antennas .. but it looks to me that
it's simply a "fat" folded dipole. I would think that I could
construct it's equivalent using the basic homemade folded dipole
approach.

http://www.boatenna.com/framesample1_000002.htm

Any other suggestions for a do-it-yourself antenna? It's not often
that I want to watch TV when on the boat (i.e. the reason I'm out
there) so I was hoping to build something myself out of thick guage
wire and 300ohm antenna wire.

Would 2 stacked folded dipoles with a 90deg offset (and "X") be an
effective approach?

If I just do the loop, what would you recommend the diameter be for
mid-range VHF5-13 or so?

Thanks in advance
Angelo

In article ,
Angelo Guarino wrote:

I wish to hoist an antenna up a sailboat mast on a halyard to help
receive TV stations when out in the Chesapeake Bay. The challenge is
that the boat will rotate at anchor with the wind and even turn the
antanna on it's axis as it it "hoisted" by rope and not locked
rotationally.

There are commercially available antennas .. but it looks to me that
it's simply a "fat" folded dipole. I would think that I could
construct it's equivalent using the basic homemade folded dipole
approach.

http://www.boatenna.com/framesample1_000002.htm

Any other suggestions for a do-it-yourself antenna? It's not often
that I want to watch TV when on the boat (i.e. the reason I'm out
there) so I was hoping to build something myself out of thick guage
wire and 300ohm antenna wire.

Would 2 stacked folded dipoles with a 90deg offset (and "X") be an
effective approach?

That would work - it's a "turnstile" configuration.

Another fairly common approach is to build a 300-ohm folded dipole,
and then bend the dipole into an "S" shape. This gives it a fairly
omnidirectional pattern, eliminating the null-off-the-end of a
straight dipole. You could probably build one of these out of
heavy-gauge copper or aluminum wire.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

"Dave Platt" wrote in message
...
In article ,
Angelo Guarino wrote:

I wish to hoist an antenna up a sailboat mast on a halyard to help
receive TV stations when out in the Chesapeake Bay. The challenge is
that the boat will rotate at anchor with the wind and even turn the
antanna on it's axis as it it "hoisted" by rope and not locked
rotationally.

There are commercially available antennas .. but it looks to me that
it's simply a "fat" folded dipole. I would think that I could
construct it's equivalent using the basic homemade folded dipole
approach.

http://www.boatenna.com/framesample1_000002.htm

Any other suggestions for a do-it-yourself antenna? It's not often
that I want to watch TV when on the boat (i.e. the reason I'm out
there) so I was hoping to build something myself out of thick guage
wire and 300ohm antenna wire.

Would 2 stacked folded dipoles with a 90deg offset (and "X") be an
effective approach?

That would work - it's a "turnstile" configuration.

Another fairly common approach is to build a 300-ohm folded dipole,
and then bend the dipole into an "S" shape. This gives it a fairly
omnidirectional pattern, eliminating the null-off-the-end of a
straight dipole. You could probably build one of these out of
heavy-gauge copper or aluminum wire.

I buit an S shaped folded dipole like this for my camper years ago. Like you
I did nt want it for watching a lot of TV.Just get weather reports and such,
Mine was about 10 ft long before bending it into an S and I used a good
quality preamp with it. Actually I was quite surprised at how well it
worked.

Angelo: Did you build the "turnstyle" shaped antennae? I'm assuming it
looked like an X in a circle...is that correct? If you have the time,
what type of material did you use and how many feet did you need? Did you
use a preamp, and if so, what is a preamp? I'm not too savvy on radios and
electronics, but want a good, economical, antennae for the commercial radio
when I'm sailing the CHX, and to watch some TV when I'm in the dock.

Thanks.

"Angelo Guarino" wrote in message
om...
I wish to hoist an antenna up a sailboat mast on a halyard to help
receive TV stations when out in the Chesapeake Bay. The challenge is
that the boat will rotate at anchor with the wind and even turn the
antanna on it's axis as it it "hoisted" by rope and not locked
rotationally.

There are commercially available antennas .. but it looks to me that
it's simply a "fat" folded dipole. I would think that I could
construct it's equivalent using the basic homemade folded dipole
approach.

http://www.boatenna.com/framesample1_000002.htm

Any other suggestions for a do-it-yourself antenna? It's not often
that I want to watch TV when on the boat (i.e. the reason I'm out
there) so I was hoping to build something myself out of thick guage
wire and 300ohm antenna wire.

Would 2 stacked folded dipoles with a 90deg offset (and "X") be an
effective approach?

If I just do the loop, what would you recommend the diameter be for
mid-range VHF5-13 or so?

Thanks in advance
Angelo


I made a "utility antenna for my 26 foot coast-wise sailor, just a folded
dipole with a PVC pipe 'X' to support the twin lead. You can size the PVC to
suit the size of the dipole. It worked okay, nothing special though. Another
version made in the same manner is a 10 meter transmitting antenna and it also
is a reasonable compromise. Getting it up as high as possible seems to help
too. I use a 'Mast staff' and hoist it to above the mast head in use.