End insulators -- purpose?
 

Do I need a dogbone or egg insulator at each end of my dipole, or can
I just splice the antenna wire to the nylon braid that runs to my
trees?

Is the answer different for, say, under 100 watts vs 1,000 watts? HF
vs. VHF?

I would probably put a small nylon thimble in the nylon braid to
provide a decent radius for the wire end.

Ken KC2JDY

Ken
(to reply via email
remove "zz" from address)

"Ken" wrote in message
...
Do I need a dogbone or egg insulator at each end of my dipole, or can
I just splice the antenna wire to the nylon braid that runs to my trees?

Answer: maybe. The nylon braid is OK so long as it never gets wet and
absorbs water or if you let it thoroughly dry before transmitting.

I bought my XYL a high-$$$ all-band vertical and a tuner. It rained hard
one night. The next AM she noted that she had to retune to get the SWR
normal but she fired up her 100 watts and made several QSO's. Then she
barely heard an old friend signing off with another station so she turned on
her 'killer-watt' and called him. They'd barely got thru exchanging calls
and into the pleasantries when she noticed a smell ..... luckily only the
tubes were fried. She turned off the amp and saw that the SWR was out of
sight - until she returned the tuner to it's usual settings for that freq.
I was soon swinging from the trees installing dipoles for each band -- with
insulators!

"Vito" wrote

"Ken" wrote
Do I need a dogbone or egg insulator at each end of my dipole, or can
I just splice the antenna wire to the nylon braid that runs to my trees?

Answer: maybe. The nylon braid is OK so long as it never gets wet and
absorbs water or if you let it thoroughly dry before transmitting.

I bought my XYL a high-$$$ all-band vertical and a tuner. It rained hard
one night. The next AM she noted that she had to retune to get the SWR
normal but she fired up her 100 watts and made several QSO's. Then she
barely heard an old friend signing off with another station so she turned
on
her 'killer-watt' and called him. They'd barely got thru exchanging calls
and into the pleasantries when she noticed a smell ..... luckily only the
tubes were fried. She turned off the amp and saw that the SWR was out of
sight - until she returned the tuner to it's usual settings for that freq.
I was soon swinging from the trees installing dipoles for each band --
with
insulators!

Hi Vito, I don't see any connection between frying tubes on an amp from an
"all band vertical" with tuner settings that were not "it's usual settings
for that freq", and having no egg-type insulators on the ends of a dipole -
did I miss something here?

I never installed the eggs on the lower antennas (fan type) of my dipole
(ran out of them at the time), and when it offered SWR of 1:1 performance
dry or in pouring rain, I just left the original copper wire to nylon line
tie-off alone. Been up for a year with no problems ever.

Jack

"Jack Painter" wrote in message
news:sg%Yc.119275$Lj.90194@fed1read03...

"Vito" wrote

"Ken" wrote
Do I need a dogbone or egg insulator at each end of my dipole, or can
I just splice the antenna wire to the nylon braid that runs to my
trees?

Answer: maybe. The nylon braid is OK so long as it never gets wet and
absorbs water or if you let it thoroughly dry before transmitting.

I bought my XYL a high-$$$ all-band vertical and a tuner. It rained
hard
one night. The next AM she noted that she had to retune to get the SWR
normal but she fired up her 100 watts and made several QSO's. Then she
barely heard an old friend signing off with another station so she
turned
on
her 'killer-watt' and called him. They'd barely got thru exchanging
calls
and into the pleasantries when she noticed a smell ..... luckily only
the
tubes were fried. She turned off the amp and saw that the SWR was out
of
sight - until she returned the tuner to it's usual settings for that
freq.
I was soon swinging from the trees installing dipoles for each band --
with
insulators!

Hi Vito, I don't see any connection between frying tubes on an amp from an
"all band vertical" with tuner settings that were not "it's usual settings
for that freq", and having no egg-type insulators on the ends of a
dipole -
did I miss something here?

I never installed the eggs on the lower antennas (fan type) of my dipole
(ran out of them at the time), and when it offered SWR of 1:1 performance
dry or in pouring rain, I just left the original copper wire to nylon line
tie-off alone. Been up for a year with no problems ever.

Jack


Uh, OK if you get away with it. But you do know that the highest currents
are at the ends of a dipole, right? Hence, you *could* set something afire!
No joy.

73

Jerry wrote:

Uh, OK if you get away with it. But you do know that the highest currents
are at the ends of a dipole, right? Hence, you *could* set something afire!
No joy.


Actually, the current is lowest and the voltage highest at the ends of a
dipole.

Roy Lewallen, W7EL

Jerry wrote:
Uh, OK if you get away with it. But you do know that the highest currents
are at the ends of a dipole, right?

Everybody knows that you really meant "highest voltage", right?
--
73, Cecil http://www.qsl.net/w5dxp



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In article ,
"Jerry" wrote:

Uh, OK if you get away with it. But you do know that the highest currents
are at the ends of a dipole, right? Hence, you *could* set something afire!
No joy.

73


Well not really, the highest "Voltages" are at the ends of a dipole, and
if one were to exceed the breakdown voltage of the insulating support
line then one could expect the possibility of problem. Other than that
it doesn't really make a difference.

Me

"Ken" wrote in message
...
Do I need a dogbone or egg insulator at each end of my dipole, or can
I just splice the antenna wire to the nylon braid that runs to my
trees?

Is the answer different for, say, under 100 watts vs 1,000 watts? HF
vs. VHF?

I would probably put a small nylon thimble in the nylon braid to
provide a decent radius for the wire end.

Ken KC2JDY

I ve done it with 500 watts up to 10 meters, No problems rain or shine.

"Jimmie" wrote

"Ken" wrote in message
...
Do I need a dogbone or egg insulator at each end of my dipole, or can
I just splice the antenna wire to the nylon braid that runs to my
trees?

Is the answer different for, say, under 100 watts vs 1,000 watts? HF
vs. VHF?

I would probably put a small nylon thimble in the nylon braid to
provide a decent radius for the wire end.

Ken KC2JDY

I ve done it with 500 watts up to 10 meters, No problems rain or shine.


And thus another radio-myth is dispelled....

I doubt anyone disagrees that insulators which help support the radio
apparatus industry, er, I mean the ends of the dipole, are "proper"
connections. But I'll gladly show pictures to anyone who doubts that the
(8.9 mhz length) 1/4 wave ends of my dipole are operating that way. And
there is indisputable evidence I have operated this way at very long ranges
during icestorms, torrential downpours, and even hurricanes. Never saw a
noticeable variation in the consistent 1.1 to 1 SWR as indicated on the
tuner. So the 30 odd feet of string holding the ends of the 8mhz components
of the dipole are definitely not robbing it or shorting out.

I also doubt Marconi would have a problem with that!

Jack

On Tue, 31 Aug 2004 23:48:02 -0400, "Jack Painter"
wrote:


"Jimmie" wrote

"Ken" wrote in message
...
Do I need a dogbone or egg insulator at each end of my dipole, or can
I just splice the antenna wire to the nylon braid that runs to my
trees?

Is the answer different for, say, under 100 watts vs 1,000 watts? HF
vs. VHF?

I would probably put a small nylon thimble in the nylon braid to
provide a decent radius for the wire end.

Ken KC2JDY

I ve done it with 500 watts up to 10 meters, No problems rain or shine.


And thus another radio-myth is dispelled....

I doubt anyone disagrees that insulators which help support the radio
apparatus industry, er, I mean the ends of the dipole, are "proper"
connections. But I'll gladly show pictures to anyone who doubts that the
(8.9 mhz length) 1/4 wave ends of my dipole are operating that way. And
there is indisputable evidence I have operated this way at very long ranges
during icestorms, torrential downpours, and even hurricanes. Never saw a
noticeable variation in the consistent 1.1 to 1 SWR as indicated on the
tuner. So the 30 odd feet of string holding the ends of the 8mhz components
of the dipole are definitely not robbing it or shorting out.

I also doubt Marconi would have a problem with that!

Jack


I guess it just depends on how often you want to re-hang an antenna.
The antenna wire will certainly cut through the nylon string or cord
far quicker than it will a ceramic or polymer-type dogbone or egg.

Bob
k5qwg