Peter Hendra wrote in
:

I don't mind shelling out US$200 if it will provide even a modest gain
in reception or transmission. What is your angle on this?

Given that I do buy it, where is the best place to install it, apart
from permanently below the water line?



If you already have a good earth (ground to the Americans), adding
another one probably will make no difference. I would like the ground
(er, ah earth) cable that connects the HF tuner to the ocean to be
installed with NO SHARP CORNERS in the most direct path available. Make
SMOOTH, not necessarily neat, turns. NEVER make a sharp turn with coax
cable, I don't care how neat it looks. Sharp turns in the earth bus act
like little inductors in series between your tuner and your earth...not
good...raises the impedance of the earth to the tuner.

To show you how futile this is on a sailboat, let me describe the earth
used at an AM broadcast station.....

If we drive a 3 meter ground rod into the ground at the base of the AM
tower, which is the AM stations actual antenna like your backstay
probably is your HF installation, it will work. However, it will not
work "good"....near as "good" as 36 sections of bridge cable arranged out
horizontally, radially, from a big, heavy cable ring at the base of the
tower to hook the transmitter's earth to. It's called a "counterpoise"
and creates an artificial earth in even very poorly conducting soil.

Now, you can, while you're at sea traveling ahead and not backing over
it, create a pseudo copy of this earth with a single wire hooked straight
to the tuner's ground post, thrown directly overboard to trail out in the
ocean behind the boat...straight as you can get it. The longer the
better, but a good length is from 15-35 meters long. DON'T forget to
roll it up as you come into port so it fouls rudder or screw! This dirty
little secret is a MUCH better earth for your HF radio than anything
screwed under the hull. Even hookup wire will work, but a nice old piece
of stainless winch cable with lots of open strands that won't rust makes
a fantastic trailing-earth ground. Try it with and without....doing a
retune on the tuner as it WILL change the feedpoint impedance of your HF
antenna quite drastically, once connected.

No big $$$ outlay is necessary....just an old piece of stainless cable,
tied off to a sturdy handrail post or the base of the backstay below the
bottom insulator is fine. Don't worry about it sinking. If it were
100' STRAIGHT DOWN, which it won't be unless you're becalmed, that would
be BEST! It doesn't need a dragging anchor to attract the really big
fish, either. If you like, you can just trail it out when making HF
calls, then coil it back in to store it. Works great...

Larry W4CSC
--
Geez, a ham letting out his secret weapons...how awful...(c;

Larry wrote:

snip
Now, you can, while you're at sea traveling ahead and not backing over
it, create a pseudo copy of this earth with a single wire hooked straight
to the tuner's ground post, thrown directly overboard to trail out in the
ocean behind the boat...straight as you can get it. The longer the
better, but a good length is from 15-35 meters long. DON'T forget to
roll it up as you come into port so it fouls rudder or screw! This dirty
little secret is a MUCH better earth for your HF radio than anything
screwed under the hull. Even hookup wire will work, but a nice old piece
of stainless winch cable with lots of open strands that won't rust makes
a fantastic trailing-earth ground. Try it with and without....doing a
retune on the tuner as it WILL change the feedpoint impedance of your HF
antenna quite drastically, once connected.

No big $$$ outlay is necessary....just an old piece of stainless cable,
tied off to a sturdy handrail post or the base of the backstay below the
bottom insulator is fine. Don't worry about it sinking. If it were
100' STRAIGHT DOWN, which it won't be unless you're becalmed, that would
be BEST! It doesn't need a dragging anchor to attract the really big
fish, either. If you like, you can just trail it out when making HF
calls, then coil it back in to store it. Works great...

Larry W4CSC

Larry,

I'll bet it does work great. I studied field
theory in engineering school, but I wouldn't have
thought of this without you mentioning it.

Now if I can only remember this when I need it ;-)

Also, it'd sure be great if lightning grounds were
this simple... But unfortunately...

Don W.

Don W wrote in
. net:

Larry wrote:

snip
Now, you can, while you're at sea traveling ahead and not backing
over it, create a pseudo copy of this earth with a single wire hooked
straight to the tuner's ground post, thrown directly overboard to
trail out in the ocean behind the boat...straight as you can get it.
The longer the better, but a good length is from 15-35 meters long.
DON'T forget to roll it up as you come into port so it fouls rudder
or screw! This dirty little secret is a MUCH better earth for your
HF radio than anything screwed under the hull. Even hookup wire will
work, but a nice old piece of stainless winch cable with lots of open
strands that won't rust makes a fantastic trailing-earth ground. Try
it with and without....doing a retune on the tuner as it WILL change
the feedpoint impedance of your HF antenna quite drastically, once
connected.

No big $$$ outlay is necessary....just an old piece of stainless
cable, tied off to a sturdy handrail post or the base of the backstay
below the bottom insulator is fine. Don't worry about it sinking.
If it were 100' STRAIGHT DOWN, which it won't be unless you're
becalmed, that would be BEST! It doesn't need a dragging anchor to
attract the really big fish, either. If you like, you can just trail
it out when making HF calls, then coil it back in to store it. Works
great...

Larry W4CSC

Larry,

I'll bet it does work great. I studied field
theory in engineering school, but I wouldn't have
thought of this without you mentioning it.

Now if I can only remember this when I need it ;-)

Also, it'd sure be great if lightning grounds were
this simple... But unfortunately...

Don W.



When you're at the dock or anchored out, drop a small anchor with the
ground wire attached off the back of the boat overboard, but not touching
bottom so it will follow you around as the boat swings around. My anchor
is a beer can filled with sand. This holds the OTHER half of your
massive dipole vertically in the perfect groundwater for great HF
comms....

PLEASE put a tag on the engine controls to remind you the HF ground is
overboard before starting the engine and blaming me for the fouled prop
backing down...thanks.


Larry
--

Don W wrote in news:vMwXh.19209
:

Also, it'd sure be great if lightning grounds were
this simple... But unfortunately...



Actually, they ARE that simple. Trail two more ground cables, during the
storms, attached to the port and starboard shrouds to trail off electrons
to the sea, right where it's SO easy to attach them at the
deck/chainplates. Don't be neat...use hefty stainless winch cable,
stranded gets the best ground. Find something to stow them in at the
base of the shrouds when not in lightning storms. Great grounds are easy
in the ocean....that don't HAVE to be through a hole in that leaky hull!

Just let the cable trail back on either side in the wake. It only
matters that they are submerged, not skipping along the surface. On our
ketch, at 6 knots, skipping along the surface would be a miracle...(c;

Larry
--

On Thu, 26 Apr 2007 00:14:18 +0000, Larry wrote:


Larry,
A few questions from a dummy in this area.

What diameter should I make the floating ground for the aerial (4mm ?)

I did try trailing a chain and weight on the end of a cable from the
base of the port shroud as alightning ground but the damn thing was
bumping annoyingly against the hull. My back stay is split at the
masthead - one is the aerial for SSB and the other is entire. Could I
attach a cable to that and throwm it ovewr the stern? - or would two
attached to the capshrouds give better protection? I unashamdely admit
to being terrified of being struck again - not a personal fear but one
of having to shell out all those dollars again to replace it all.

I got sick of pulling all the plugs out from the instruments when
lightning hove in the distance - in our path, so I put the 13 wires to
the radar unit for example to a 15 pin plug that just pulls apart -
other instruments likewise. N o more hiolding a colured Visio
schematic and trying to figure colours in the dark.

I should have shaved my arms before antifouling - I am still picking
it off despite cleaning up and showering.

cheers
Peter
Don W wrote in news:vMwXh.19209
:

Also, it'd sure be great if lightning grounds were
this simple... But unfortunately...



Actually, they ARE that simple. Trail two more ground cables, during the
storms, attached to the port and starboard shrouds to trail off electrons
to the sea, right where it's SO easy to attach them at the
deck/chainplates. Don't be neat...use hefty stainless winch cable,
stranded gets the best ground. Find something to stow them in at the
base of the shrouds when not in lightning storms. Great grounds are easy
in the ocean....that don't HAVE to be through a hole in that leaky hull!

Just let the cable trail back on either side in the wake. It only
matters that they are submerged, not skipping along the surface. On our
ketch, at 6 knots, skipping along the surface would be a miracle...(c;

Larry

On Thu, 26 Apr 2007 21:04:02 -0400, Peter Hendra
wrote:

On Thu, 26 Apr 2007 00:14:18 +0000, Larry wrote:


Oh, and what is an optimum length and diameter - covered in plastic or
bare? - I know, only a project manager would want precision such as
this.

Thanks for all of this Larry. I shall follow your advice.

By the way, I have been dutifully hoarding my softdrink/soda/pop
plastic bottles. I even have a large hanging laundry bag to store them
in after rinsing them. However, my favourite drinks here in Trinidad
are Lemon, Lime and Bitters sold by the Angostura company in small
glass bottles and cans of coconut and pineapple fizzy drink. Are you
aware of any techiques whereby I can put out "message in a can" or
"message in a small glass green bottle"? I have been drinking Coca
Cola but no longer wish to support that icon of American Imperialism
(openly at least). We called in to Assab a few years back, the large
and empty Eritrean port that had been captured back from the invading
Ethiopians. At the time, Eritrea was the second poorest nation and had
just won a war of independence against colonising Ethiopia with no
external aid despite both the US and Ruissians suppling their foes
with weapons at different times. The town had nothing but a single
main unpaved street, and apart from the port wharves and cranes was
largely unchanged since the Italians colonised it after the Great War.
There were a lot of little cafes making great, strong and flavoursome
(eat your heart out Vic) espresso coffee with beautifully maintained
polished brass and copper machines dating back to the 1920's. The only
other non-alcoholic drink was good old Coca-Cola kept cool with ice.
Expectedly, both tasted divine.

I only ask about the cans as I recognise the spirit of a lateral
thinking mind and you are wholely responsible for my collection
fetish/mania. I almost ate a half eaten hamburger from a rubbish bin
the other day - it looked delicious but some people I knew were
looking. Still, as my Zoology professor said - "The good germs fight
the bad germs and the good germs usually win".

Waiting for it...............
cheers
Peter the dumpster man


Larry,
A few questions from a dummy in this area.

What diameter should I make the floating ground for the aerial (4mm ?)

I did try trailing a chain and weight on the end of a cable from the
base of the port shroud as alightning ground but the damn thing was
bumping annoyingly against the hull. My back stay is split at the
masthead - one is the aerial for SSB and the other is entire. Could I
attach a cable to that and throwm it ovewr the stern? - or would two
attached to the capshrouds give better protection? I unashamdely admit
to being terrified of being struck again - not a personal fear but one
of having to shell out all those dollars again to replace it all.

I got sick of pulling all the plugs out from the instruments when
lightning hove in the distance - in our path, so I put the 13 wires to
the radar unit for example to a 15 pin plug that just pulls apart -
other instruments likewise. N o more hiolding a colured Visio
schematic and trying to figure colours in the dark.

I should have shaved my arms before antifouling - I am still picking
it off despite cleaning up and showering.

cheers
Peter
Don W wrote in news:vMwXh.19209
:

Also, it'd sure be great if lightning grounds were
this simple... But unfortunately...



Actually, they ARE that simple. Trail two more ground cables, during the
storms, attached to the port and starboard shrouds to trail off electrons
to the sea, right where it's SO easy to attach them at the
deck/chainplates. Don't be neat...use hefty stainless winch cable,
stranded gets the best ground. Find something to stow them in at the
base of the shrouds when not in lightning storms. Great grounds are easy
in the ocean....that don't HAVE to be through a hole in that leaky hull!

Just let the cable trail back on either side in the wake. It only
matters that they are submerged, not skipping along the surface. On our
ketch, at 6 knots, skipping along the surface would be a miracle...(c;

Larry

On Thu, 26 Apr 2007 21:41:17 -0400, Peter Hendra
wrote:


There were a lot of little cafes making great, strong and flavoursome
(eat your heart out Vic) espresso coffee with beautifully maintained
polished brass and copper machines dating back to the 1920's. The only
other non-alcoholic drink was good old Coca-Cola kept cool with ice.
Expectedly, both tasted divine.

I do miss the espressos I often had in coastal European towns when in
the Navy years ago. I suspect this is due to my youth at the time and
the ambience of the surroundings more than the coffee itself, or just
an entirely faulty memory. In any case, good espresso is available
nearby, but the experience would certainly not be Ethiopian.
Your Coke reference brings to mind some other experience that may be
useful to those in the tropics and not having ice available.
My boiler room was normally @ 110-120 degrees F. when steaming in the
daytime Caribbean.
We boilermen often stood near powered vents to gain comfort from the
cool 100 degree air forced in from the sunny outside decks.
I always (after my first cruise, that is) brought some cans of Coke on
cruises, kept in my boiler room locker, which would hold about 12
cans. They became quite valuable after a few weeks at sea, and I was
offered as much as $5 for a can.
My monthly salary was @ $90 then. Anyway, I never sold any, but did
give away a few.
Our method of cooling a can of soda in the boiler room was to wrap it
in a wet rag and place it in a vent. The strength of the air blowing
there was very strong. Maybe 30 knots. The rag was wetted as many
times as necessary to cool the soda. Repeated wetting only whetted
the appetite for the imminent treat.
Can't say exactly how cold it got the soda, but I'd estimate 70
degrees or less. Damn cold relatively speaking.
And in the case of cooling Coke in a Navy boiler room, I am a
relativist.
Whether this would work for tropical sailors I don't know.

--Vic

On Thu, 26 Apr 2007 22:46:54 -0500, Vic Smith
wrote:

Hi Vic,
Thanks for this tip that I had forgotten. I had expected an irate
outburst from you denying that you were a coffee philistine but you
ignored the bait.

Years ago when we used to go camping (tenting) as a young family at
our beach property we used this trick to keep fhe food cool. We had no
spare cash to buy a fridge and would hang such as milk bottles (are
you old enough to remember when milk came in bottles?) wrapped in a
wet rag from a shaded tree branch. The evaporation kept it cool. I
also had a couple of open sided large concrete building blocks (8
inches wide ones to give a 16 inch square) buried in the sandy ground
- 2 high with a concrete paving stone on top. It also was in the shade
and kept constantly damp. Both worked very well.

I taught science at highschool for a couple of years then and am
trying to remember the science of it. Something about the latent heat
of evaporation and the energy required to turn the water into a gas
and why methylated spirits or alcohol rubbed on the skin gives a
greater cooling feeling than does water. It turns into a gas at a
lower temperature. Memory is dim on this.

I understand your memories of having coffee at some of the places you
must have visited in the Med. My family being from Crete, I was raised
on the Greek/Turkish style of heating it on a sand brazier in a small
pot which I sometimes drink on the boat though I do prefer Italian
style espresso. Unfortunately I don't have the power for a decent
expresso machine onboard though I have one at home.

My best coffee memory is of rising at 5 am in the hotel in Cairo (I am
an early riser) and going to a 24 hour cafe to have coffee and a
shisha (huba buba water filtered smoking device) in the street with
other regulars on their way to and from work. Same as you, probably
the ambiance.

I agree. There is nothing quite like a cold coke when you are thirsty
and hot. Must be the caffiene hit and thus the resultant addiction.
Damned economic imperialism. It should be included in the war on
drugs.

Incidentally, as to our term 'philistine', it appears that it is a
misnomer and that it was the Israelites who were the unsophisticated
tribal barbarians who had migrated in from the desert and who were the
destroyers. The Israeli archeological department and academics have
recently excavated many Philistine cities and have expressed this view
themselves. They have shown that the Philistines were from Mycenean
Greece and were the kin of Agamemnon, Menelaus, Ulysses, and Achilles
(who was of course my direct ancestor on my mother's father's side of
the family). They had a very definite high level of sophisticated
manufacture of bronze, gold and pottery and also used traded goods
from all over the known world, being maritime merchants themselves
which is why these cities were founded along the coast.

Before I get castigated for being anti-Israeli (I'm not) by those who
make an overly simple connection, look it up on the web. I am
fascinated by the proven connection they have made with the many
references in historical literature throughout the Middle East to the
"sea peoples". It was always a mystery as to who they were and where
they came from.

If you are interested, also look up the 14th century BC bronze age
shipwreck that is now displayed in the museum at Bodrum castle in
Turkey. It contains items from all over the then known world and shows
the well developed trade links between nations. Bronze, wine and olive
oil were the base products for international commerce then, not
Coca-Cola.

Yes, I know that this is off topic, but this is why I 'cruise' - to
visit these places and see and experience in the first person. My
occupation is in modern technology but my passion is for history.

cheers
Peter

Our method of cooling a can of soda in the boiler room was to wrap it
in a wet rag and place it in a vent. The strength of the air blowing
there was very strong. Maybe 30 knots. The rag was wetted as many
times as necessary to cool the soda. Repeated wetting only whetted
the appetite for the imminent treat.
Can't say exactly how cold it got the soda, but I'd estimate 70
degrees or less. Damn cold relatively speaking.
And in the case of cooling Coke in a Navy boiler room, I am a
relativist.
Whether this would work for tropical sailors I don't know.

--Vic

Peter Hendra wrote in
:

Oh, and what is an optimum length and diameter - covered in plastic or
bare? - I know, only a project manager would want precision such as
this.

Thanks for all of this Larry. I shall follow your advice.



Optimum length would be 5% longer than 1/4 wavelength of the frequency
you are operating on. 1/4 wavelength in meters is 75.7/frequency in Mhz.

So, if we are on 6 Mhz, for instance, we get 75.7/6 x 1.05 = 13.2 meters.

But, because the radiating element ISN'T a proper length and we are using
a tuner, just make it LONG and the tuner will tune out the reactance and
match it up...

--------------------------------------------------

On another issue you have brought up, you said you had two backstays in
parallel, one with insulators that is the antenna and one that is not and
is solidly connected to the mast, right??

If this is so, in close proximity to the radiating element, that second
backstay is simply absorbing a major part of your radiation from the real
antenna, greatly reducing your actual field strength at some remote
receiver. We can't stop induced, out of phase, RF currents in any of the
rigging, but you can reduce it, greatly, giving you a nicely stronger
signal.

If these backstays are as I think, please consider putting insulators at
equal distance in BOTH backstays,not just one. Then, run a jumper
between upper end of the bottom insulators, effectively paralleling them.
Feed the tuner into the CENTER of this jumper, which can also be two
equal-length wires from the HV output of the tuner to the two insulator
feedpoints. The effect of doing this is a radiator that is MUCH greater
in "virtual diameter", both radiating IN PHASE, which aids their field
strength. Instead of the second backstay absorbing the signal, it will
create more signal, in phase. If your tuner is below them, you can
either make a T to feed the two backstays or just Y them out of the
tuner, itself, with EQUAL LENGTH conductors to preserve their phase
relationship.

Larry
--
Antennas R Us
If it doesn't glow blue after dark, power output is down.....(c;

Thanks Larry,
You are making my simple mind spin.

Seriously though, I am truly appreciative of your advice in this and
all matters. What you say about backstay aerials makes sense and I
shall do as you suggest. What I would really like, as do most others,
is long range voice comms. If anything reasonable helps in any way, I
will do it. There is nothing quite so annoying as to not be able to
receive an interpretable weather fax because of poor reception.

I'll add the ground from my stays. By the way, I neglected to tell
that I have a painted box section wooden mast, deck stepped. Forestay,
backstays and capshrouds are electrically connected due to their
attachment at the head of the mast. There is an aluminium sailtrack
which has no connection. Should this be a factor for consideration?

My specific area of small expertise over the past few years has been
packet data and such as better compression algorithms, up and down
linking to comms satellites, and the problem of latency or delay in
resending packets - solved by a really neat way of transmitting two
packet streams, with a slight delay on the second. If one packet
address is missing or denatured in some way, "it" merely grabs its
copy from the second incoming stream without having to ask the
originator for a resend and the consequent latency or time delays
whilst waiting - speeds it up no end. Probably been invented before
somewhere else but that sort of thing happens all the time. The
tracking system can track all of our active patrol boats as well as
Indonesia's ( and give postion, direction, speed and a lot of other
data in sub minute real time as well as sending and receiving text
messages and orders. If we needed to, we could add engine revs,
temperature and a lot of other really uinnecessary stuff.

Even though mobile phones are just glorified two channel radios, So
far as radio propagation (and most of the rest of it) has failed to
lodge in my brain successfully.

Thanks again for being so helpful and for freely disseminating your
experienced advice to those such as me whom you will probably never
meet.

cheers
Peter

On Fri, 27 Apr 2007 16:33:31 +0000, Larry wrote:

Peter Hendra wrote in
:

Oh, and what is an optimum length and diameter - covered in plastic or
bare? - I know, only a project manager would want precision such as
this.

Thanks for all of this Larry. I shall follow your advice.



Optimum length would be 5% longer than 1/4 wavelength of the frequency
you are operating on. 1/4 wavelength in meters is 75.7/frequency in Mhz.

So, if we are on 6 Mhz, for instance, we get 75.7/6 x 1.05 = 13.2 meters.

But, because the radiating element ISN'T a proper length and we are using
a tuner, just make it LONG and the tuner will tune out the reactance and
match it up...

--------------------------------------------------

On another issue you have brought up, you said you had two backstays in
parallel, one with insulators that is the antenna and one that is not and
is solidly connected to the mast, right??

If this is so, in close proximity to the radiating element, that second
backstay is simply absorbing a major part of your radiation from the real
antenna, greatly reducing your actual field strength at some remote
receiver. We can't stop induced, out of phase, RF currents in any of the
rigging, but you can reduce it, greatly, giving you a nicely stronger
signal.

If these backstays are as I think, please consider putting insulators at
equal distance in BOTH backstays,not just one. Then, run a jumper
between upper end of the bottom insulators, effectively paralleling them.
Feed the tuner into the CENTER of this jumper, which can also be two
equal-length wires from the HV output of the tuner to the two insulator
feedpoints. The effect of doing this is a radiator that is MUCH greater
in "virtual diameter", both radiating IN PHASE, which aids their field
strength. Instead of the second backstay absorbing the signal, it will
create more signal, in phase. If your tuner is below them, you can
either make a T to feed the two backstays or just Y them out of the
tuner, itself, with EQUAL LENGTH conductors to preserve their phase
relationship.

Larry