"David Robbins" wrote in message
...

"Adam T. Cately" wrote in message
...
SNIP

I haven't read the rest of the thread, but here's something glaringly
obvious...

Grounding will be easy when I get around to it - I have
baseboard hot water radiators that I can ground to.

NEVER ground to hot water pipes - ALWAYS use the cold water pipe,
as it goes directly to the earth outside the building. The hot water
pipes are routed through the hot water heater(s) and are NOT a direct
path to ground.


first a couple of truisms:
NEVER say NEVER.
NEVER believe anyone who asserts an ALWAYS.
In the end an easy job is rarely as easy as you first thought.

That being said, NEVER rely on pipes of any kind for safety (either AC or
lightning) grounding of equipment, ALWAYS run your own wire to the proper
ground rod or electrical service connection as required by electrical
codes.

RF "grounds" are another problem. The problem here is to remember that
any
conductor more than a small fraction of a wavelength will have currents
induced in it and thus have a different voltage at one end than the other
when exposed to an HF RF field. The real aim here is two fold: First, to
provide a low resistance path for 'ground' currents back to the antenna
end
of the feedline so the currents in the feedline can be properly balanced.
Second, to keep all equipment and personel in the antenna field near the
same potential to prevent injury and reduce interference.



Ha! Great point!

I'm planning on buying a Radio Shack outlet tester (22-141, pg 238 of
the last catalog) - if it shows my outlets are configired properly, I plan
on
running a heavy insulated ground wire from the outlet to the pipe (8").

Does this sound right to you? As far as RF goes, I can touch *any*
component of the system and not see any DC current, SWR or other
changes at all when transmitting so I guess I've got a pretty good RF
ground already.

Then there is the performance issue - the solar numbers haven't been
very good for some time but yesterday I worked stations coast to
coast on 20 & 40 with 5 watts and got some impressive signal reports.
So, whatever I'm doing, it seems to be working OK.

72's all De Ken KG0WX/QRP

"Ken Bessler" wrote in message
...

"David Robbins" wrote in message
...

"Adam T. Cately" wrote in message
...
SNIP

I haven't read the rest of the thread, but here's something
glaringly
obvious...

Grounding will be easy when I get around to it - I have
baseboard hot water radiators that I can ground to.

NEVER ground to hot water pipes - ALWAYS use the cold water pipe,
as it goes directly to the earth outside the building. The hot water
pipes are routed through the hot water heater(s) and are NOT a direct
path to ground.


first a couple of truisms:
NEVER say NEVER.
NEVER believe anyone who asserts an ALWAYS.
In the end an easy job is rarely as easy as you first thought.

That being said, NEVER rely on pipes of any kind for safety (either AC
or
lightning) grounding of equipment, ALWAYS run your own wire to the
proper
ground rod or electrical service connection as required by electrical
codes.

RF "grounds" are another problem. The problem here is to remember that
any
conductor more than a small fraction of a wavelength will have currents
induced in it and thus have a different voltage at one end than the
other
when exposed to an HF RF field. The real aim here is two fold: First,
to
provide a low resistance path for 'ground' currents back to the antenna
end
of the feedline so the currents in the feedline can be properly
balanced.
Second, to keep all equipment and personel in the antenna field near the
same potential to prevent injury and reduce interference.



Ha! Great point!

I'm planning on buying a Radio Shack outlet tester (22-141, pg 238 of
the last catalog) - if it shows my outlets are configired properly, I plan
on
running a heavy insulated ground wire from the outlet to the pipe (8").

Does this sound right to you? As far as RF goes, I can touch *any*
component of the system and not see any DC current, SWR or other
changes at all when transmitting so I guess I've got a pretty good RF
ground already.

Then there is the performance issue - the solar numbers haven't been
very good for some time but yesterday I worked stations coast to
coast on 20 & 40 with 5 watts and got some impressive signal reports.
So, whatever I'm doing, it seems to be working OK.

72's all De Ken KG0WX/QRP


tying the radiator to the electric service neutral probably won't hurt. if
the radiator is plumbed with metal pipe and is up to code they are probably
tied together somewhere else also. and its always a good idea to be sure
your outlets are wired properly, especially in older homes.

if you can touch stuff and not see any changes that probably means that you
have a low enough resistance connection back the the feedline point at the
antenna. that is where lots of people mess up, they ground the shack end of
the coax, but then connect just the center conductor to a random wire or
something like that outside. this arrangement forces the return current to
flow through ground, the shack equipment, back out the outside of the coax
and then back inside the coax to complete the circuit. this causes all
sorts of problems like the infamous rf burns from the key or mic,
interference to nearby tv, stereo, and computer equipment, etc. even
balanced lines and antennas are susceptable to this. if the antenna isn't
really balanced (say one leg is near the house the other is in the clear)
the unbalance in the return path can cause current to flow back through
wiring in the house to get back to the feedline.

with the poor solar conditions right now you are probably doing just fine,
just be sure you have a good safety ground and enjoy.

NEVER ground to hot water pipes - ALWAYS use the cold water pipe,
as it goes directly to the earth outside the building. The hot water
pipes are routed through the hot water heater(s) and are NOT a direct
path to ground.

==========================

Not entirely correct.

ALWAYS use the cold water pipe.

And if you have a hot water pipe ALWAYS connect that in parallel.

Two connections in parallel ALWAYS have a lower impedance than either of
them.

Hot water, wall-mounted, central heating radiators are convenient connecting
points.

If you have a gas pipe then make it a three-some.

And of course take advantage of the electricity supply ground via the
domestic power wiring.

If there's a 14-gauge wire running from a bedroom shack, through the window,
down the outside wall, to a bunch of buried radials in the back yard then
include it with the others.

The whole system is just a bunch of random length radials and, up to a
break-even point, the more the merrier.

If any one of the principal ground connections can be broken without having
any affect on the tuner settings then you've already gone far enough.

But whatever you have there's no guarantee you will be free of RF in the
shack. RF comes in through the windows, ceiling, walls, doors and floor of
the shack direct from the high-power near-field of the antenna. And you
can't criticise the antenna - it's only doing its job.

If in a bedroom, as a last desperate resort, take up the carpet or lino and
cover the floor-boards with chicken wire. Re-lay the carpet or lino. Connect
the chicken wire from two spaced points to the terminal at the rear of the
PA which is marked "Ground".
----
Reg, G4FGQ

The previous posting, of course, applies to RF grounding of the radio shack,
particularly to end-fed antennas where at some frequencies there may be
appreciable RF currents flowing from the shack down to ground via the very
uncritical arrangements previously described.

If there are any local or national regulations to be complied with regarding
the domestic power frequency safety ground then they should be complied
with. But in general such regulations, by themselves, will fall far short of
an adequate radio ground.

For example, a single safety ground rod, wherever it is located, will likely
have a resistance at all frequencies greater than 50 ohms plus the important
inductive reactance of all the wire between the shack and the rod. By all
means include the rod in the station's RF ground system but it will be found
to be amongst the ground connections which can be disconnected without
having any effect on station operation such as tuner settings.

A single rod is no better than a buried horizontal radial wire of the same
length. If a rod is the only RF ground available an endfed antenna will work
in some poor fashion, RF in the shack, etc., unless the local soil is
saturated with salt water - an unlikely condition.

To protect the family home from direct lightning strikes on the antenna then
the mast etc., is best provided with its own ground electrode system. We
have very few thunder storms in the UK. In all my years I have seen only one
lightning strike which hit the ground. So what I have done when a storm
seemed imminent (the tuner capacitor sparking over) is just disconnect the
antenna at the lead-in to the shack and toss the loose end of the wire as
far as I can along the back yard.

For antenna + mast grounding details I leave to more experienced people.
---
Reg, G4FGQ

In article ,
Ken Bessler wrote:

I'm planning on buying a Radio Shack outlet tester (22-141, pg 238 of
the last catalog) - if it shows my outlets are configired properly, I plan
on running a heavy insulated ground wire from the outlet to the pipe (8").

Does this sound right to you?

I would advise _against_ doing this, for a couple of reasons.

One is that the Radio Shack tester can detect certain forms of
mis-wiring, but there's at least one which it cannot detect. This is
one in which you have a three-wire outlet, hooked up to a two-wire
power feed (one which doesn't actually have a ground), and the
installer simply wired the "neutral" and "ground" screws together at
the outlet.

To a simple static-voltage-based tester (such as the Radio Shack one
appears to be) this outlet will test out as "good" - there will be 120
volts between hot and neutral, 120 between hot and ground, and zero
between neutral and ground.

However, this sort of outlet does _not_ provide a true safety ground.
If you start drawing a large amount of current through the wire (from
this outlet or from another on the same wire), both the "neutral" and
"ground" contacts will be pulled several volts away from ground by the
I*R losses in the neutral wire. If you've got your equipment chassis
"grounded" to this outlet, the chassis will be pulled up away from
ground - this could present a shock hazard. Also, you can end up with
some portion of the power return current (back to the neutral
connector at the breaker box) flowing where you don't want it...
through your equipment chassis, your hot-water pipe, your
antenna-cable coax braid, etc.

Proper testing for a neutral/ground crossconnection may require
physical inspection of the outlet. It can, I think, also be detected
by measuring the voltage between the neutral and ground pins at an
outlet, while drawing a heavy current (e.g. a 1500-watt space heater)
through the other side of that outlet. If the outlet is wired
properly, you _should_ see at least a volt or so develop between these
two pins - if you don't, it may indicate a neutral/ground crossconnect
at that outlet.

The other reason I'd discourage wiring the power-outlet ground to your
hot-water-heater pipe, is that the National Electric Code doesn't
permit this. If a short circuit occurs somewhere on this circuit, it
would cause your water pipes to carry some of the current back to the
house ground, and this could result in a shock hazard for anyone in
contact with the pipes (e.g. somebody in a shower or tub).

As I recall, the electrical and plumbing systems really should remain
electrically isolated from one another _except_ at a single "bonding"
point. This ensures that the plumbing system cannot carry
ground-return currents, if a fault occurs in the electrical wiring.

--
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!

Hi all,
the electrical codes differ in different countries. Consult the
current one in your country.

One is that the Radio Shack tester can detect certain forms of
mis-wiring, but there's at least one which it cannot detect. This is
one in which you have a three-wire outlet, hooked up to a two-wire
power feed (one which doesn't actually have a ground), and the
installer simply wired the "neutral" and "ground" screws together at
the outlet.
This setup was legal and widely used in Czechoslovakia for many years.
Now it should not be used in new or reconstructed instalations, but it
is still in use in thousands of houses and flats. It doesn't seem
hazardous provided that the network is fused properly.

...
The other reason I'd discourage wiring the power-outlet ground to your
hot-water-heater pipe, is that the National Electric Code doesn't
permit this. If a short circuit occurs somewhere on this circuit, it
would cause your water pipes to carry some of the current back to the
house ground, and this could result in a shock hazard for anyone in
contact with the pipes (e.g. somebody in a shower or tub).
The Czech code requires to interconnect all tubing and conductive
items in a bathroom and connect them to the protective wire
(protective AND NEUTRAL in older installations, see higer)...

BR from Ivan

OK1SIP wrote:
Hi all,
the electrical codes differ in different countries. Consult the
current one in your country.

#snip# neutral-ground interconnection

This setup was legal and widely used in Czechoslovakia for many years.
Now it should not be used in new or reconstructed instalations, but it
is still in use in thousands of houses and flats. It doesn't seem
hazardous provided that the network is fused properly.

#snip# ground/piping interconnection

The Czech code requires to interconnect all tubing and conductive
items in a bathroom and connect them to the protective wire
(protective AND NEUTRAL in older installations, see higer)...

BR from Ivan

Fascinating information, Ivan - thanks very much! "Curiouser and
curiouser..."

--
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!