On Sunday, June 19, 2011 4:41:43 PM UTC-5, Michael wrote:
the next issue is earth ground and lightning
protection. my shack is on the second floor of my house. in order to
deal with rf and lighting with my short wave set up, i went with an
inverted L that is grounded to an 8 foot brass rod through the
matching transformer. i dont have any rf problems with this set up
even though my radio is not grounded in the shack. for lightning
protection, i disconnect my coax feed and hang it out the window when
I'm not using the radio. i've already read a pile of stuff on line
already about other people that have had the same problem with a
second floor location, but I'm still not sure what I'm going to do
about grounding the transceiver when I hook it up to a dipole.

Using a dipole, which is a complete antenna, there
is no need to have an RF ground. And no need to ground
the radio, unless there is a high voltage safety reason
for it. "safety ground". But any outlet with a ground
pin will provide that.
With the case of the Kenwood 12v rig, that is not
the case. Only the power supply that feeds it needs a
safety ground. And most all those have a third ground pin
on the plug.
But you do need to worry about lightning. But less with
a dipole, than a vertical that is on the house.
The horizontal wire will be less likely to stream than
a vertical. So less likely to attract a strike.
But it can still happen. It would be best to run the
feed line straight down to ground, and then under or
along the ground to the shack. But this is kind of
impractical with a typical ladder line setup.
The worst case for damage is to have the feed line
running elevated in the air to the 2nd floor shack.
So if you have to run it like that, you sure don't
want it connected when storms are in the area.
I'd have some way to totally disconnect it from
the house on the outside when not in use.

This is one reason why I generally prefer coax.
Easier to mitigate the effects of lightning..
I can snub lines to ground at the base of masts,
connect and snub through a "ground window" at the
entrance to the shack, and generally it's easier
to use the typical lightning arresters.
Ladder line is harder to deal with in these aspects.
Or at least to me..
But you can use gas tubes on each conductor, etc..
That would require a good lightning ground outside.
And all grounds outside should route to a central
point, and be tied together to keep all at the same
potential.
If you use a mast to support the apex of the dipole,
it's more likely to be struck than the wire antenna
itself. So it's best to use a metal mast that is
grounded at the base. I don't use any non conductive
masts here.
I have no RF ground in the shack. Except for rare
cases, I don't believe in them. I've found they
usually cause more problems than they solve.
These problems would usually rear their ugly heads
when I would kick in some RF horsepower.. What is not
yet a problem at 100w, can be a real pain at a KW+.
:/

On Jun 19, 9:30*pm, wrote:
On Sunday, June 19, 2011 4:41:43 PM UTC-5, Michael wrote:

*the next issue is earth ground and lightning

protection. *my shack is on the second floor of my house. *in order to
deal with rf and lighting with my short wave set up, i went with an
inverted L that is grounded to an 8 foot brass rod through the
matching transformer. *i dont have any rf problems with this set up
even though my radio is not grounded in the shack. *for lightning
protection, i disconnect my coax feed and hang it out the window when
I'm not using the radio. * *i've already read a pile of stuff on line
already about other people that have had the same problem with a
second floor location, but I'm still not sure what I'm going to do
about grounding the transceiver when I hook it up to a dipole.

Using a dipole, which is a complete antenna, there
is no need to have an RF ground. And no need to ground
the radio, unless there is a high voltage safety reason
for it. "safety ground". But any outlet with a ground
pin will provide that.
With the case of the Kenwood 12v rig, that is not
the case. Only the power supply that feeds it needs a
safety ground. And most all those have a third ground pin
on the plug.
But you do need to worry about lightning. But less with
a dipole, than a vertical that is on the house.
The horizontal wire will be less likely to stream than
a vertical. So less likely to attract a strike.
But it can still happen. It would be best to run the
feed line straight down to ground, and then under or
along the ground to the shack. But this is kind of
impractical with a typical ladder line setup.
The worst case for damage is to have the feed line
running elevated in the air to the 2nd floor shack.
So if you have to run it like that, you sure don't
want it connected when storms are in the area.
I'd have some way to totally disconnect it from
the house on the outside when not in use.

This is one reason why I generally prefer coax.
Easier to mitigate the effects of lightning..
I can snub lines to ground at the base of masts,
connect and snub through a "ground window" at the
entrance to the shack, and generally it's easier
to use the typical lightning arresters.
Ladder line is harder to deal with in these aspects.
Or at least to me..
But you can use gas tubes on each conductor, etc..
That would require a good lightning ground outside.
And all grounds outside should route to a central
point, and be tied together to keep all at the same
potential.
If you use a mast to support the apex of the dipole,
it's more likely to be struck than the wire antenna
itself. So it's best to use a metal mast that is
grounded at the base. I don't use any non conductive
masts here.
I have no RF ground in the shack. Except for rare
cases, I don't believe in them. I've found they
usually cause more problems than they solve.
These problems would usually rear their ugly heads
when I would kick in some RF horsepower.. What is not
yet a problem at 100w, can be a real pain at a KW+.
:/

Thanx for the input... One of the reasons i was considering an OCF
dipole over a ladder fed "ballanced" dipole at first was a matter of
lightning protection. With an ocf dipole, i can use 50 ohm coax as
the feed line. not to much trouble to use a gas tube. Though, i'll
probably stick with my current method and just disconnect the feed
line and hang it out the window even if I use an arrestor. i'm also
told by a few other people that putting a sharp 90 degree bend in the
feedline outside the shack is an old trick that usually helps in the
case of a direct strike. i'd gather that static coming down the
feedline would probably be the more common worry.

On 6/19/2011 8:10 PM, Michael wrote:
Thanx for the input... One of the reasons i was considering an OCF
dipole over a ladder fed "ballanced" dipole at first was a matter of
lightning protection. With an ocf dipole, i can use 50 ohm coax as
the feed line. not to much trouble to use a gas tube. Though, i'll
probably stick with my current method and just disconnect the feed
line and hang it out the window even if I use an arrestor. i'm also
told by a few other people that putting a sharp 90 degree bend in the
feedline outside the shack is an old trick that usually helps in the
case of a direct strike. i'd gather that static coming down the
feedline would probably be the more common worry.

Nobody seems to have asked the burning question that's really
important... what's your budget?

As far as kind of antenna, feedline, etc.

You're not going to have an optimum on all bands. For right now, as the
sunspots are coming up, the high bands seem to be working fairly well
(and as a Tech, all you get is 10m anyway, as far as phone.. but when
you get your General or Extra, you'll get the rest.. study and take that
test..)

I'm a huge fan of autotuners *at the feed*. You don't have to spend
your time trying to adjust the antenna, or worrying about feedline loss,
or any of a zillion other things. Sure, there's some loss in the tuner,
but it's pretty easy to get the antenna close, and if the antenna is
"close" then the autotuner takes care of the rest.

Life is too short to try and prune radials for resonance, and then have
it go out of tune when the tree next to the antenna grows, etc.

Folks who have tube amps have the tuner built into to the output
network, and they're used to the whole thing of tuning every time they
change frequency, so for them, open wire line to their rig is fine. Do
the match at the amp end, the loss from mismatch in the line is small
because the line is high Z, etc. But that's not typical of a "brand
new" station: solid state 100W amp, coax feed, etc.



My own preference is for an autotuner at the feedpoint of some sort of
dipole or inverted V. Any of the 10-15-20-40 multi wire band dipoles
will work quite well, and with an autotuner, you don't have to worry
about "pruning to exact length". The two sides don't have to be equal
length, even. Be aware that not all tuners can tune all impedances, and
you generally do NOT want a transformer between antenna and tuner (esp
if there's a lot of reactance to tune out), so going too far in the OCF
direction may be counter productive. Then you can feed with coax,
which is a whole lot more convenient than any sort of open wire line.

Second choice which is less visually obtrusive is some sort of vertical
with an autotuner at the base and an adhoc counterpoise of random length
wires. Higher the base, the better, in general.


Lightning protection..

Where are you located? A lightning alley like mid Florida? Or somewhere
were lightning is an unusual thing (like Southern California)?

Gas tube arrestor is a nice idea. What will you hook the ground on that
arrestor to? A stake pounded in outside where the coax comes in? Make
sure that you run a bonding wire from the stake to the electrical system
ground. A concrete encased grounding electrode is even better (Ufer ground)

Or, if you're not really in a big lightning area, just use the arrestor
as a "receiver input overvoltage protector", for whatever good it might
do. (I don't know what a TS590 input looks like, but the couple hundred
volts from the arrestor might blow it up...). disconnect the coax when
your not using it. BTW, short the coax with something and make sure
it's not close to something that might catch fire if you do get a
lightning hit.



The 90 degree thing is useless.. there's no significant impedance in a
90 degree bend. If you get a direct hit, unless you're spending a fair
amount of time and effort on a good system, you're going to get
damage..You don't want to spend thousands of dollars on a lightning
protection system to protect a 1000 dollar rig.

Static discharge *is* a problem.. but, if you hook the shield to the
third wire ground (or that other grounding system), on a dipole, that
pretty much takes care of it. Maybe a 100k resistor between the legs
(or between the vertical and ground).. Once the center insulator gets a
bit grungy, leakage resistance will solve that problem for you.

On Jun 20, 11:46*am, Jim Lux wrote:
On 6/19/2011 8:10 PM, Michael wrote:

Thanx for the input... One of the reasons i was considering an OCF
dipole over a ladder fed "ballanced" dipole at first was a matter of
lightning protection. *With an ocf dipole, i can use 50 ohm coax as
the feed line. not to much trouble to use a gas tube. *Though, i'll
probably stick with my current method and just disconnect the feed
line and hang it out the window even if I use an arrestor. *i'm also
told by a few other people that putting a sharp 90 degree bend in the
feedline outside the shack is an old trick that usually helps in the
case of a direct strike. *i'd gather that static coming down the
feedline would probably be the more common worry.

Nobody seems to have asked the burning question that's really
important... what's your budget?

I had in mind a max of $500.00 total.

As far as kind of antenna, feedline, etc.

You're not going to have an optimum on all bands. *For right now, as the
sunspots are coming up, the high bands seem to be working fairly well
(and as a Tech, all you get is 10m anyway, as far as phone.. *but when
you get your General or Extra, you'll get the rest.. study and take that
test..)

I'm a huge fan of autotuners *at the feed*. *You don't have to spend
your time trying to adjust the antenna, or worrying about feedline loss,
or any of a zillion other things. *Sure, there's some loss in the tuner,
but it's pretty easy to get the antenna close, and if the antenna is
"close" then the autotuner takes care of the rest.

Life is too short to try and prune radials for resonance, and then have
it go out of tune when the tree next to the antenna grows, etc.

Folks who have tube amps have the tuner built into to the output
network, and they're used to the whole thing of tuning every time they
change frequency, so for them, open wire line to their rig is fine. *Do
the match at the amp end, the loss from mismatch in the line is small
because the line is high Z, etc. *But that's not typical of a "brand
new" station: solid state 100W amp, coax feed, etc.

My own preference is for an autotuner at the feedpoint of some sort of
dipole or inverted V. *Any of the 10-15-20-40 multi wire band dipoles
will work quite well, and with an autotuner, you don't have to worry
about "pruning to exact length". *The two sides don't have to be equal
length, even. *Be aware that not all tuners can tune all impedances, and
you generally do NOT want a transformer between antenna and tuner (esp
if there's a lot of reactance to tune out), so going too far in the OCF
direction may be counter productive. * Then you can feed with coax,
which is a whole lot more convenient than any sort of open wire line.

Second choice which is less visually obtrusive is some sort of vertical
with an autotuner at the base and an adhoc counterpoise of random length
wires. * Higher the base, the better, in general.

Lightning protection..

Where are you located? *A lightning alley like mid Florida? Or somewhere
were lightning is an unusual thing (like Southern California)?

im in the northeastern most corner of NJ. not exactly lightning
alley, but we get storms regularly. about five years ago, one of my
radios got fried. i almost always remembered to disconnect my coax
and hang it out the window, but the one time i did not, i paid for
it. an icom pcr 1000 was left connected to my antenna switch during a
storm. i did not even think about it until a few days later, when i
went to use the radio. it powered up, but nothing else worked. i sent
it to icom and they told me it was a sure bet that static or lightning
was the culprit. since then, I have not forgotten to go through my
routine :-)

Gas tube arrestor is a nice idea. *What will you hook the ground on that
arrestor to? A stake pounded in outside where the coax comes in? *

That is what I had in mind. I already have an 8' brass rod in the
ground for my inverted L.

Make
sure that you run a bonding wire from the stake to the electrical system
ground. *A concrete encased grounding electrode is even better (Ufer ground)


Or, if you're not really in a big lightning area, just use the arrestor
as a "receiver input overvoltage protector", for whatever good it might
do. *(I don't know what a TS590 input looks like, but the couple hundred
volts from the arrestor might blow it up...). *disconnect the coax when
your not using it. *BTW, short the coax with something and make sure
it's not close to something that might catch fire if you do get a
lightning hit.

All I have to short a feed line to on the second floor is a metal
heating system radiator :-) Probably not the best choice. So... I
just let it hang out the wondow when not in use.

The 90 degree thing is useless.. there's no significant impedance in a
90 degree bend. If you get a direct hit, unless you're spending a fair
amount of time and effort on a good system, you're going to get
damage..You don't want to spend thousands of dollars on a lightning
protection system to protect a 1000 dollar rig.

makes perfect sense to me... so... i have always tried to go with
"some protection is better than none". though, many are fond of
saying that "*some* lighting protection = zero protection"

Static discharge *is* a problem.. but, if you hook the shield to the
third wire ground (or that other grounding system), on a dipole, that
pretty much takes care of it. *Maybe a 100k resistor between the legs
(or between the vertical and ground).. Once the center insulator gets a
bit grungy, leakage resistance will solve that problem for you.