I am using a random wire antenna which runs outdoors through a hole in a
window frame.

I do not have access to any good RF grounding system and plan to use an
indoor
counterpoise wire from the ground connection on the tuner (MFJ-949E). I have
a
nice role of #18 wire, the end is connected to the tuner, and it is my
intention to
unroll it along the floor through my suite until such time as it is properly
tuned.

MY QUESTION IS - How can I tell when I have unrolled the right amount of
wire
for the frequency in use. I know it will not be 1/4 wave, and that it
should be less.
From what I understand, when it is adjusted properly I should not have any
hot
RF burning my lips from the mike. Checking it with my lips is not what I
call
a desireable means of testing, and being single I cannot call my wife to
test it
for me. I'd like to find a better way and hence my questions.

I believe (according to what theory I have learned) that the tuner chassis
would
be hot with RF, with the amount of RF becoming less and less as the
counterpoise
wire approaches the proper length. If this is true would a simple RF sniffer
tell me?
I can rig one up fairly easily.

OR - What would I be looking for using my MFJ-259B SWR Analyzer? I expect
what it would show readings similar to a dipole with resonance at the
operating
frequency and an impedance (resistive) of somewhere in the order of 60 ohms.
plus or minus -- is this a correct assumption?

OR -- does anyone on the group have any suggestions that will tell me when
the
system is properly adjusted -- the simpler the better!

Once I have found how to do this, I can put tape markings on the roll of
counterpoise wire to show the appropriate length for each band or narrow
band of frequencies in which I will be operating.

I have already tested the hole -- it is just a little less than 1/4 inch
diamater,
but that seems to be enough to let both sidebands through -- I carefully
tested
that using AM which proves that two sidebands can fit through the hole at
the
same time, which allows me to further assume that either the upper or lower
sidebands should squeeze through easily! :-)

Thanks in advance for any assistance you can provide in this matter.

Irv VE6BP

On the air finally but afraid to get to close to the mike! I may have
to use rubber gloves and teflon lip gloss!

"Irv Finkleman" wrote in message
...


snip
I should not have any hot
RF burning my lips from the mike. Checking it with my lips is not what I
call
a desireable means of testing, and being single I cannot call my wife to
test it
for me. I'd like to find a better way and hence my questions.

Since you started this whimsical line of reasoning, you dare not object:
Buy a plastic microphone. Har-har-HAR-dee-har-har! [Thanks to Ralph
Kramden]

But seriously folks ...

You do have a coaxial cable from the radio to the tuner. Choke the
bejabbers out of it. Either wind the coax itself into one or more physical
coil(s) of the right proportions or use the W2DU method.

This will be useful for the former approach:
http://www.karinya.net/g3txq/temp/choke_impedances.png
It illustrates that no single coil really does it.

.... and this for the latter:
http://www.qsl.net/ta1dx/amator/W2du.jpg
Although your application doesn't involve using beads as a balun, per the
illustration, the broad approach is the same: blocking common mode currents.

"Sal"
who chokes his cables and gets no shocks





I believe (according to what theory I have learned) that the tuner chassis
would
be hot with RF, with the amount of RF becoming less and less as the
counterpoise
wire approaches the proper length. If this is true would a simple RF
sniffer tell me?
I can rig one up fairly easily.

OR - What would I be looking for using my MFJ-259B SWR Analyzer? I expect
what it would show readings similar to a dipole with resonance at the
operating
frequency and an impedance (resistive) of somewhere in the order of 60
ohms.
plus or minus -- is this a correct assumption?

OR -- does anyone on the group have any suggestions that will tell me when
the
system is properly adjusted -- the simpler the better!

Once I have found how to do this, I can put tape markings on the roll of
counterpoise wire to show the appropriate length for each band or narrow
band of frequencies in which I will be operating.

I have already tested the hole -- it is just a little less than 1/4 inch
diamater,
but that seems to be enough to let both sidebands through -- I carefully
tested
that using AM which proves that two sidebands can fit through the hole at
the
same time, which allows me to further assume that either the upper or
lower
sidebands should squeeze through easily! :-)

Thanks in advance for any assistance you can provide in this matter.

Irv VE6BP

On the air finally but afraid to get to close to the mike! I may have
to use rubber gloves and teflon lip gloss!

You shouldn't need to unroll the wire at all since you're using a tuner. Just hook it up and tune away.

Irv,

I think you will find it difficult to tune up using a MFJ-949E, random wire antenna and a roll of wire run around your apartment. You will probably end up with a "hot mike" most of the time. Even if you get it all tuned up on one frequency as soon as you QSY to a different frequency you will have to change the counterpoise wire length. Finding the right lengths for different frequencies and coiling/uncoiling the wire each time you QSY will get old fast.

I have a better solution for you. Buy an MFJ artificial ground so that you can use a fixed length of wire under the carpet and tune the counterpoise from the operating position. MFJ makes a standalone product called the MFJ-931 or a tuner that includes the artificial ground - MFJ-934. Here are some links to these products:

http://www.mfjenterprises.com/Produc...ductid=MFJ-931
http://www.mfjenterprises.com/Produc...ductid=MFJ-934

Hope things work out for you and that you get back on the air in the near future. Let us know how things work out for you.

Roger

On Tue, 24 Apr 2012 16:08:10 -0600, "Irv Finkleman"
wrote:

I am using a random wire antenna which runs outdoors through a hole in a
window frame.

I do not have access to any good RF grounding system and plan to use an
indoor
counterpoise wire from the ground connection on the tuner (MFJ-949E). I have
a
nice role of #18 wire, the end is connected to the tuner, and it is my
intention to
unroll it along the floor through my suite until such time as it is properly
tuned.

MY QUESTION IS - How can I tell when I have unrolled the right amount of
wire
for the frequency in use.

I once had the little B&W vertical in a 3rd story apartment window. To
tune it, I used an SWR meter and simply unrolled my single
counterpoise wire across the rug until the swr was 1:1 for the band in
use. The counterpoise was on a wire spool. I never actually measured
the counterpoise length -- I simply found 40 meters meant the wire
went from the bedroom window to the kitchen.

bob
k5qwg

I know it will not be 1/4 wave, and that it
should be less.
From what I understand, when it is adjusted properly I should not have any
hot
RF burning my lips from the mike. Checking it with my lips is not what I
call
a desireable means of testing, and being single I cannot call my wife to
test it
for me. I'd like to find a better way and hence my questions.

I believe (according to what theory I have learned) that the tuner chassis
would
be hot with RF, with the amount of RF becoming less and less as the
counterpoise
wire approaches the proper length. If this is true would a simple RF sniffer
tell me?
I can rig one up fairly easily.

OR - What would I be looking for using my MFJ-259B SWR Analyzer? I expect
what it would show readings similar to a dipole with resonance at the
operating
frequency and an impedance (resistive) of somewhere in the order of 60 ohms.
plus or minus -- is this a correct assumption?

OR -- does anyone on the group have any suggestions that will tell me when
the
system is properly adjusted -- the simpler the better!

Once I have found how to do this, I can put tape markings on the roll of
counterpoise wire to show the appropriate length for each band or narrow
band of frequencies in which I will be operating.

I have already tested the hole -- it is just a little less than 1/4 inch
diamater,
but that seems to be enough to let both sidebands through -- I carefully
tested
that using AM which proves that two sidebands can fit through the hole at
the
same time, which allows me to further assume that either the upper or lower
sidebands should squeeze through easily! :-)

Thanks in advance for any assistance you can provide in this matter.

Irv VE6BP

On the air finally but afraid to get to close to the mike! I may have
to use rubber gloves and teflon lip gloss!

Thanks Sal, Roger, and Bob as well as
the many others who have not yet replied
-- actually my mic is plastic.

I truly appreciate your assistance, but I think
I really need to explain my rationale somewhat.

The real intent of my questioning is to provide
a counterpoise system whereas the tuner does
not just have an unbalance by simply feeding
the random wire, but a balance achieved
whereby the counterpoise connected to the
tuner acts as the other (missing) half of the
unbalanced system, thereby balancing it just
as the ground image does with a quarter wave
antenna. Does this make sense? If not, wait till
you read further about MFJ and the push and
pull explanation.

I have two tuners at my disposal -- one is an
MFJ-949E Deluxe Versa Tuner II -- a common T
match configuration. The other is an MFJ-1625
Window/Balcony Mount Antenna which contains
matching circuitry and also a loading coil
for tuning the counterpoise wire or wires.
I hope to use the 949E, if I can resolve the
matter of knowing when the counterpoise
is properly adjusted. It is this matter that
I am trying to resolve to my satisfaction. I
could equally use the MFJ-1625 which is
just an MFJ-1623 with a 12 ft whip and
an 80m loading coil.

I'm fairly well read on antennas, but still my
knowledge of this monumental subject is very
limited i.e. to me a Smith Chart is something
belonging to a hospital patient named Smith.
I sort of understand the concept of the
counterpoise acting as the missing half of the
system, but have difficulty putting it into words.


MFJ, in the MFJ-1625 Manual say....

QUOTE
It is always important to have a good RF ground,
provided by the counterpoise, when using any
whip or long-wire antenna. This is because the
MFJ-1623 tuner needs something to "push"
against in order to force current into the antenna.
If a good RF ground is not available, RF will usually
find its way back into the power line (RFI),
transmitter audio circuits (RF feedback),
or the operator (RF burns). Water pipes provide
good dc and ac safety grounds, but they are
often inadequate for RF grounding because they
are long single conductors. RF grounds
require large "spread out" surfaces with direct
multiple connections to the equipment ground
point. Water pipes, heating ducts, or multiple
ground rods may work (especially if they are all
connected together with jumper wires), but the
best RF grounds are radial systems or
multi-wire counterpoises.
UNQUOTE

I have to admit that this explanation contains
terms like long-wire antenna used in what I think
might be confusing or ill-defined ways, but the
idea of push and pull of antenna current feels
right. If this is not already confusing, it is the
MFJ-1625 Manual, but the tuner is an MFJ-1623.
Many hams use the term MFJ as standing
for 'Mighty Fine Junk', and at times I agree, but
I do have good skills as a technicial and find that
a little resoldering and tightening of ground nuts
turns it into somewhat better than any of the
homebrew or modifications I have ever put on
the air. I no longer have a house, shack, workshop,
and tower, etc,etc,etc and am now working with
largely storebought items and limited space.

I have considered a cabin in the mountains where
I would not interfere with anyone around, but where
would I find one with built in housekeeping and
meals? Just the expense of the extension cord alone
makes me shudder.

I am not as concerned about a case of 'rf lip' as I am
about stray RF causing possible problems with the
neighbours on all sides of me, with all my electronic
toys such as computers, DVD players, the local
fire-alarm system and other such things. The last
thing I want to do is draw attention to the fact that I
am running a ham radio station from my suite until
I know I am not causing any problems.

Thusly, my goal is to provide myself with a first rate
RF ground system, entirely contained within my suite,
in order that I do not wake up at night with the fire
alarms set off and great numbers of disturbed
residents gathered around pointing at me and saying
'Ham! Ham! For Shame! For Shame!' and the Residents
Council having special meetings to decide how to deal
with me. They already think I'm crazy -- and I may be
somewhat, but I don't want to make matters worse!

So, having herein explained my rational, lets see what
help I can get in the way of producing the ideal indoor
low-cost non-radiating counterpoise radial system.

Actually, I have lots of wire for the radials, the
tuner contains a loading coil to assist in tuning
the counterpoise, and my big concern is how do
I determine when the counterpoise is operating
effectively. The metering system in the tuner should
reach a peak and subside on either side of the
correct counterpoise tuning point, and what I
really need to know is how to determine when the
stray RF is minimized if not eliminated.

I have to explain that I do all this in a somewhat
humorous manner, I find all my predicaments funny,
but then I brought myself into them and this is the
only way, short of outright denial, of dealing with them.

You have probably already noticed that I am a
man of few words!

Irv VE6BP

P.S. In a previous topic where the matter of electrons
escaping from the end of the antenna was hotly
debated, I have solved that problem by forming a
wee loop at the end of the antenna, thereby taking
any of those loose electrons and feeding them back
into the wire! I used the loop and a nylon cable tie
to fasten the end of theantenna into the tree which
supports most of it, thereby eliminating the cost of
a ceramic insulator and it's accompanying end effect.
I'm sure Tesla and Marconi could have used some of
my simple practical solutions like this one, and perhaps
negated the necessity of long discussions re electrons
escaping from antennas.


"Irv Finkleman" wrote in message
...
I am using a random wire antenna which runs outdoors through a hole in a
window frame.

I do not have access to any good RF grounding system and plan to use an
indoor
counterpoise wire from the ground connection on the tuner (MFJ-949E). I
have a
nice role of #18 wire, the end is connected to the tuner, and it is my
intention to
unroll it along the floor through my suite until such time as it is
properly tuned.

MY QUESTION IS - How can I tell when I have unrolled the right amount of
wire
for the frequency in use. I know it will not be 1/4 wave, and that it
should be less.
From what I understand, when it is adjusted properly I should not have any
hot
RF burning my lips from the mike. Checking it with my lips is not what I
call
a desireable means of testing, and being single I cannot call my wife to
test it
for me. I'd like to find a better way and hence my questions.

I believe (according to what theory I have learned) that the tuner chassis
would
be hot with RF, with the amount of RF becoming less and less as the
counterpoise
wire approaches the proper length. If this is true would a simple RF
sniffer tell me?
I can rig one up fairly easily.

OR - What would I be looking for using my MFJ-259B SWR Analyzer? I expect
what it would show readings similar to a dipole with resonance at the
operating
frequency and an impedance (resistive) of somewhere in the order of 60
ohms.
plus or minus -- is this a correct assumption?

OR -- does anyone on the group have any suggestions that will tell me when
the
system is properly adjusted -- the simpler the better!

Once I have found how to do this, I can put tape markings on the roll of
counterpoise wire to show the appropriate length for each band or narrow
band of frequencies in which I will be operating.

I have already tested the hole -- it is just a little less than 1/4 inch
diamater,
but that seems to be enough to let both sidebands through -- I carefully
tested
that using AM which proves that two sidebands can fit through the hole at
the
same time, which allows me to further assume that either the upper or
lower
sidebands should squeeze through easily! :-)

Thanks in advance for any assistance you can provide in this matter.

Irv VE6BP

On the air finally but afraid to get to close to the mike! I may have
to use rubber gloves and teflon lip gloss!

"Irv Finkleman" wrote in message
...

The real intent of my questioning is to provide
a counterpoise system whereas the tuner does
not just have an unbalance by simply feeding
the random wire, but a balance achieved
whereby the counterpoise connected to the
tuner acts as the other (missing) half of the
unbalanced system, thereby balancing it just
as the ground image does with a quarter wave
antenna. Does this make sense?

Yes and perhaps I have a workable idea to get there.

First, an assumption: Your long wire out the window frame has only a short
run to the tuner. That is, the tuner is on the same wall as the window
frame and is near the window. How'm I doing so far?

Along that same wall, stretch out a heavy piece of straight wire -- can be
insulated but you'll cut through the insulation as needed -- from corner to
corner. It's like a workbench ground bus but it's not grounded, per se.

Attach the tuner ground to it.

Buy two (maybe more) locking metal tape rules. Craftsman, Lever-lock. At
the zero ends, securely bolt or clamp the metal tape rules to the ends of
the heavy wire in each corner. Yes, you're ruining the tape rules by
mutilating the ends but we know you're desperate. Courage, man!

Stretch out the tape rules until their lengths become whatever you need for
a workable counterpoise, recalling that HF antenna elements (and
counterpoises) do not need to run in perfect straight lines. Zig-zagging is
your friend in a confined space. Even go up the wall(s) in the far corners.

This method, if it works, has a bonus. Once the lengths are established for
each band, the exact lengths can be eyeballed directly off the tape rules
and noted. Alternatively, just scrawl band numbers on the walls. (Hi-hi)

"Sal"
Never one to let anything serve only a single purpose.

"Irv Finkleman" napisa³ w wiadomo¶ci
...

MFJ, in the MFJ-1625 Manual say....

QUOTE
It is always important to have a good RF ground,
provided by the counterpoise, when using any
whip or long-wire antenna. This is because the
MFJ-1623 tuner needs something to "push"
against in order to force current into the antenna.
If a good RF ground is not available, RF will usually
find its way back into the power line (RFI),
transmitter audio circuits (RF feedback),
or the operator (RF burns). Water pipes provide
good dc and ac safety grounds, but they are
often inadequate for RF grounding because they
are long single conductors.

You wrote: " I have a nice role of #18 wire, the end is connected to the
tuner, and it is my
intention to unroll it along the floor through my suite until such time as
it is properly
tuned."

So it will be: "a long single conductors"


RF grounds
require large "spread out" surfaces with direct
multiple connections to the equipment ground
point. Water pipes, heating ducts, or multiple
ground rods may work (especially if they are all
connected together with jumper wires), but the
best RF grounds are radial systems or
multi-wire counterpoises.

So you should not unroll it but have "all connected together with jumper
wires".

Jta is the same opinion: "You shouldn't need to unroll the wire at all since
you're using a tuner.
Just hook it up and tune away."
The hook = jumped wire.



P.S. In a previous topic where the matter of electrons
escaping from the end of the antenna was hotly
debated,

I'm sure Tesla and Marconi could have used some of
my simple practical solutions like this one, and perhaps
negated the necessity of long discussions re electrons
escaping from antennas.

There was also Sir Oliver Lodge. He demonstrated the escaping of electrons
from the antinodes (see Fig. 2):

He also discovered that HF do not like the long conductors;
"The electrical charge stored in the Leyden jars could flow either through
the very low dc resistance path provided by the loop of wire or it could
flow across the very high resistance path through the air between the
spark-gap terminals at B. It would seem that the obvious path for the charge
to follow would be through the low resistance wire loop. Surprisingly, Lodge
was able to produce very large sparks across the spark-gap, B, even though
the dc resistance of the wire across the gap was only a fraction of an
ohm.[4]"

I am trying to "descend you into the same bottomless pit"
S*

"Sal" wrote in message ...

"Irv Finkleman" wrote in message
...

The real intent of my questioning is to provide
a counterpoise system whereas the tuner does
not just have an unbalance by simply feeding
the random wire, but a balance achieved
whereby the counterpoise connected to the
tuner acts as the other (missing) half of the
unbalanced system, thereby balancing it just
as the ground image does with a quarter wave
antenna. Does this make sense?

Yes and perhaps I have a workable idea to get there.

First, an assumption: Your long wire out the window frame has only a
short run to the tuner. That is, the tuner is on the same wall as the
window frame and is near the window. How'm I doing so far?

Bang on Sal -- the tuner is located about 18 inches from where the
wire comes through the window, but on the floor along the wall
with the window is the baseboard hot water heating unit so I can't
really run anything on the floor along that wall. Similarly, although I
understand your tape measure idea, there is a simpler solution
which I tested last night and worked perfectly.

I arrived at a solution through the following note from Bob, K5QWG
who wrote:

"I once had the little B&W vertical in a 3rd story apartment window. To
tune it, I used an SWR meter and simply unrolled my single
counterpoise wire across the rug until the swr was 1:1 for the band in
use. The counterpoise was on a wire spool. I never actually measured
the counterpoise length -- I simply found 40 meters meant the wire
went from the bedroom window to the kitchen."

I thought it made perfect sense and even downloaded the instruction
manual for the B&W AP-10 Windowsill Antenna which told me the
same thing as Bob wrote -- and it worked perfectly.

I too used a spool of wire connected to the ground post on the
MFJ-949E tuner, and unrolled it away from the tuner and antenna,
across the floor and through the room. At that point I tuned up on
frequency, adjusted the tuner for minimum SWR (nearly 1 to 1)
and that was that! It worked beautifully.

Your idea with the tape measures would have worked as well,
but would have been a little more expensive and possibly
unworkable due to the heater. Instead, I simply put a tape
marker on the counterpoise wire at the length where it worked
well on the band tested (80M). Now, when I want to operate
all I have to do is unroll the spool to the tape marker and
Presto! I can go on the air! Of course I have noted the tuner
settings, and will also add further tape markers on the
counterpoise wire for the different bands, and note the
tuner settings as well.

My next step may be to cut counterpoise wires for each
band of operation and permanently lay them along the
wall this negating the need to roll and unroll the spool
of wire each time.

With time there may be some minor changes. For instance
how far across the bands can I tune without any significant
change in SWR. I might also try putting a loading coil
in the counterpoise line at the tuner end so that I can fine
tune the counterpoise length electrically. I will build up
a little RF sniffer just to check for local stray rf but
that should no longer be a problem.

I could use the MFJ-1625 tuner which has a built in
switched coil to adjust the counterpoise, but it only has
a current meter, not an swr bridge. The MFJ-949E
tuner has swr metering. Therefore if the loading coil
for the counterpoise works, I can use the 949E and
sell (albeit at a small loss hopefully) the MFJ-1625
set complete to some ham who is able to operate
using the intended setup for the 1625. It is
an excellent system, but because of all the metal in
my building which negates indoor operation,
and the inability to put the whip out of the window
due to physical limitations existing in my suite,
I cannot use it. I had not considered the limittions
in my situation prior to buying the 1625 but it was
worth the try. I might even keep it (I may have
to if I can't sell it) for portable use when I go
fishing. It would be an excellent setup on a picnic
table or from a tent. Again, time will tell,

In any event, A BIG THANK You to all who helped in
this discussion -- I can now get on the air and as soon
as I have things tested and tidied up I hope to meet
you there.

Irv, VE6BP

On Tuesday, April 24, 2012 9:11:06 PM UTC-7, Irv Finkleman wrote:

Thusly, my goal is to provide myself with a first rate
RF ground system, entirely contained within my suite,
in order that I do not wake up at night with the fire
alarms set off and great numbers of disturbed
residents gathered around pointing at me and saying
'Ham! Ham! For Shame! For Shame!' and the Residents
Council having special meetings to decide how to deal
with me. They already think I'm crazy -- and I may be
somewhat, but I don't want to make matters worse!

So, having herein explained my rational, lets see what
help I can get in the way of producing the ideal indoor
low-cost non-radiating counterpoise radial system.

Actually, I have lots of wire for the radials, the
tuner contains a loading coil to assist in tuning
the counterpoise, and my big concern is how do
I determine when the counterpoise is operating
effectively. The metering system in the tuner should
reach a peak and subside on either side of the
correct counterpoise tuning point, and what I
really need to know is how to determine when the
stray RF is minimized if not eliminated.


Irv,

Nice to hear that you got something working and are back on the air. However I want to point out some incorrect assumptions you made earlier about RFI and stray RF from counterpoises.

The subject of radiating counterpoises in an apartment was discussed in this Usenet group a few years ago. Here is a link that provides some more info for you.

How much does a counterpoise radiate? - http://www.radiobanter.com/showthread.php?t=117807

The counterpoise you have inside your apartment will definitely radiate into the building as will the length of antenna running from the tuner to the hole in the window. In another post you said you were running QRP at 5 watts. You may not have any RFI problems with other electronics in your building at these low levels. If you crank up the power to 100 watts I don't think you will be so lucky...