man involvement. There should be two clear classes.
But that isn't the primary issue for me. The issue for me is technical, and
surrounds how we plan growth when some groups simply go off on their own and
ignore bandplans and the IARU.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
. :-) My experience is this carries over to unintentional arcs.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
something entirely different in *normal operation* just because they want
to.
I'm all for what the consensus of everyone wants, and not what some specific
interest group wants. If the IARU is meaningless, then everyone should be
able to operate where they like any time they like for any r
by takeover?
My opinion is we need some sort of governing committee who we all actually
listen to, like it or not, or we will have more problems than we need to
have.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
Tom, all you have to do is open you filter up to say 1800 hz or maybe a
little more, then sit and watch how many signals you can decode on a busy
20 meter psk31 day. I regularly copy signals that are almost in the noise
while surrounded by louder signals only 20 or 30 hz away. 20 or 30
Tom, "on point" ... I am, almost exclusively, a CW and Digi op in that
order. I will say, anecdotally, that I have not experienced any
interference caused by one or the other to the other on 160. I admit that
I am not THE most active op on 160, but I am there a fair amou
operators use.
Another part is they just may not recognize CW, or what the CW station is
doing.
This is why the FCC, wisely, did not mix modes.
Like Tom I neither endorse nor object to digi activity, except as it jams
existing CW. I share his opinion that the frequency choice for digi
acti
social
interaction and to judge others as less than us.
Surely we can discuss things important to the bands like mature adults.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
Specifically, every year The Antique Wireless Association (NY, USA)
sponsors the "Bruce Kelley 1929 QSO Party" for two weekends in late
autumn: this year marks the first time that 160-meters will be added to
the existing 80- and 40-meter bands of activity. Details may be seen at
http://www.an
835 to 1840 without proper band use and
technical limitation investigation was either dumb as a rock, or terribly
inconsiderate. Anyone understanding how band usage already worked and how
**real** SSB systems work never would have used a 5 kHz slot in an are
ove, where antenna cost is low and the antenna can be a 1/2 wave or more
high Yagi. My opinion is it makes no sense at all on lowest bands to start
with TX antenna gain. The cost per dB is far too much.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
Thanks for the info. This is what I was looking for - info from someone
who
has modeled the radials and/or actual experience with measurements.
Going over the wall simplifies things for me both for the shunt fed tower
for topband and for the radials for the 80M 4-sq.
I plan on soldering the radia
e enough gain.
It would be very interesting to see what others find, if they have looked at
it.
http://www.w8ji.com/receiving.htm
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
ere sensitivity loss taking some part of the system down very near
receive system noise floor, it should be external noise limited.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
adding multiple over-the-wall wires. You only added a ~3 degree long
stub.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
I have had a longstanding problem with pulse noise off my SW BOG. The
pulses are ~5khz wide, ~1 to 1.5 S units
in amplitude, are spaced every 12 khz, do not drift (one always right on
1825!), and extend from ~1700 to 2500 khz.
Not drifting at all indicates a system with a controlled clock frequ
uld
work. If you are, even 6dB of ***real*** TX gain will not be enough.
<<work so would appreciate any comments on this rather radical change in plan,
especially by you guys at tropical latitudes.>>>
From my observations in middle-GA, this has been the worse season by far for
Hi Herb
NH8S was on this morning (1200Z). Not strong, running split, and was
busy putting NA into the log. After I got him on 160, then on 80. I
expect he will be on for a few more mornings, so you have a few more
chances (fingers crossed).
Tom - VE3CX
On Tue, Sep 11, 2012 at 2:30 PM
Some flooded foam-core F-6 starts to show what could be problematic velocity
factor changes, for critical phased arrays, below 1 MHz.
Above 1 MHz any change is lost in either measurement errors or cable
dielectric density changes.
___
UR RST IS ...
Tom I think everything is real quiet while a bunch of folks are busy
looking at manuals and crunching numbers with their analyzers.
Wes,
The problem Jim suggests is real, but the numbers are so small at HF for
normal good cables they are meaningless. Until we get a really small cable
or so
where copper skin depth is .0081 inches and we might be getting into the
steel core, or am I missing something here? :-)
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
al network analyzer.
Perhaps I have bad cables of two very different types, and all the dozens of
cables a cable manufacturer sent me over the years were all bad in the same
way.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
ent wobble.
I can't think of any systems we have that are so critical.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
Let's do some quick math 234/1.82=128.57 gives us the length in feet
of a quarter wave at 1.820 mHz.
That's not correct. The number is 245.8926/F, which is rounded to 246/F.
A quarter wave in freespace is 245.8926/1.82 = ~135.1 feet, not 128.57
234/F is a long way off.
riginal Message -
From: "LY2KZ"
To: "Tom W8JI"
Cc:
Sent: Tuesday, September 04, 2012 12:10 PM
Subject: Re: Topband: Air core chokes for 160m
Hi Tom
I (we) have 21m height mast with two sloping ~17m length top wires. There
are 25 radials each about 25m long. The ground is goo
all the different
situations, so all we really have are generalized cases that have been
offered as generalized rules.
What ground system, feedline routing, and antenna do you have? Most of the
problems, and the acceptable choice of decoupling, would depend feedline
routing and the particular
t QSO with Japan, and country 61 for me, in
1972 from Toledo, Ohio. Shortly after that I worked JA1HKP.
We are all getting old. :-)
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
Any comments one way or the other ? Tie the all together at the roof and run
one wire up or tie them to the 20 foot pipe at the roof ?>>
There is no difference at all in results, provided you make good
connections.
The choke belongs below the counterpoise, not above it.
The 3 feet simply bec
evel audio outputs, but just barely make an
acceptable low or medium level audio input connector. They are generally not
good at all for RF stuff.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
n-line), the slope is 100:1. That's 40 feet, but again
any existing obstructions around you shield your antenna.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
nstruction, or an airport under construction
that will be available for public use;
(3) An airport operated by a Federal agency or the DOD.
(4) An airport or heliport with at least one FAA-approved instrument
approach procedure.
73 Tom
___
UR R
While my humble station & mediocre efforts in the various Topband contests
hardly matter much, I try & make it a point to stay off of those "window
frequencies", unless I'm responding directly to a DX station that I might
hear thereon...>>>
I think most contests prohibit or frown upon NA stati
Out west in flyover country we rue the day. Tom is spot on. I too stay out
of 30-35 for CQing so my western brethren can potentially hear something.
Very unfortunate to have the 30-35 window, which many DX stations use,
clobbered by a very few thoughtless W CQ'ers.
I didn'
ation efficiencies of 75 percent are possible over a very
limited ground system of 18 buried radial wires only 20 feet long."
On the surface this seems to agree with what I find. There are dozens of
ways to have about the same results. I wonder what Grant has in the book
The last information I had was this 160 meter DX window was no longer in
use as a window by a international agreement of amateurs. It previously
restricted North Americans from calling CQ DX in it, while allowing other
countries to do so. I was one of the Americans calling CQ DX run out of
the w
levels/not be
very effecient. If it helps you hear, that is all that really
matters. If it is rolled up during the day, perhaps it can be rolled
out in different directions at night to favour different parts of the
world.
Good luck with the operation!!
Tom - VE3CX
On 8/28/12, Nick Henwood wrote
, or just 160?
Whatever you do, if you do it correctly, there will not be that much
difference except in logistics and flexibility.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
s. Logically, we should expect all that comes
with those voltages.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
added grounds without success. When we
looked at his tuner, it had a single core 4:1 current balun. Rewinding the
same core to a 1:1 current balun cured his problems entirely.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
I control the common mode
impedance to ensure the baluns actually do what I want. I never use them in
random situations.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
vertical wire
that might not even be radiating much if it is near a tower.
I changed the front tires to new economy six plies, fuel tank shock mounts,
changed a fuel filter, and repaired the fuel tank crack on my tractor, and
the new front tires let me mow twice as far on a tank of f
t help
people, even when others copy it.
It seems like no matter how much people freely contribute to others in this
world, it is never enough for some. They demand even more free stuff.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
put to the receiver
a bit better the gain and TOI will get a few dB better. It's pretty hard to
quantify the TOI, because control settings and receiver impedance affects
it, but someone is far better off using a "real" amplifier if needed.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
e started having problems when the limiter was added? I
haven't found a device yet with back-to-back diodes that does not ruin a
system's dynamic range. This is because the diodes start to go non-linear
resistance below the hard-clamping voltage, which is already far too low.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
>I just put in the above as it is the best one out there... However, when
> I put in the Array Solutions RF Limiter/Arrestor between the preselector
> and the K3 I get distortion in the signals. Any comments out there?
>
> The RX antenna is a Hi-Z 8-Circle array.
Antennas have a vector sum of all
's pretty
> insignificant.
> (Maybe. :-)
Power is I^2, so we can assume if we divide current between enough radials
each radial will not radiate much at any distance compared to the antenna.
We not only have cancellation at a distance, we have much
ing looks like it
comes from one point in space. Near one of the radials compared to the
others, there will be significant radiation fields unless there are many
radials dividing the current. It all comes down to levels and phase at any
point.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
nas would not work nearly as well.
We have to watch making things black and white.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
ounterpoise thing off and on:
http://www.w8ji.com/counterpoise_systems.htm
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
Hello Topbanders,
I noticed this come across another list and thought I would share it here.
Have any of you used this?
73 de Tom, K6VCR
http://users.otenet.gr/~jmsp/#dnld
This guy decided to take on the very dirty task of rewriting the 1980's
FORTRAN code that makes up the NEC2 engine
That doesn't work for me for some reason.
> -Original Message-
> From: topband-boun...@contesting.com
> [mailto:topband-boun...@contesting.com]On Behalf Of Jerry Keller (K3BZ)
> Sent: Friday, August 17, 2012 4:15 PM
> To: (REFLECTOR) Topband
> Subject: Topband: UA9YAB SK - PayPal Page
>
>
I know the Home Depot ones are not. They start to break after a couple
years. :-)
- Original Message -
From: "Mike Waters"
To: "topband"
Sent: Friday, August 17, 2012 12:42 PM
Subject: Re: Topband: Threading radials
> I've found that black Thomas & Betts Ty-Raps are UV resistant,
r
has UV inhibitors, no matter what color.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
ments.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
because we all
abandon the band until our seasonal alarm clocks ring in the late summer or
early fall. 160 is open all year, if we look on quiet days.
When no one tries, the band is closed.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
clusively AM BCB it has to be a receiver image or a spurious in the AM
transmitter.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
difference ending in five kHz, or unless the AM transmitter has a spurious
in some sort of mixing or frequency synthesis scheme, it is nearly certain
to be a receiver problem.
An attenuation test will only show nonlinearity in the receiver, and it does
not sound like that is the problem based o
ifferent things. It
tells me the phasing is far from optimum directivity phase at the high end
of the pattern frequency range. If I wanted the best 160 and 80 meter
antenna, I would intentionally forego a significant back null on 400 meters.
If I wanted a wideband null t
ectivity at
lower wave angles.
This is why people should never give up, and should experiment with the best
they can do. Even if it doesn't work close to right, it can make people
happy.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
make measurements. The best example of this
common very human effect is to change the battery in your car, clean it ,
and wax it. It will run better, and get better fuel mileage. (A popular Ham
author actually put that in an article on mobile installations!)
I think this is what Rick was drivin
> If a radial runs along the ground and then up over a wall, what difference
> would it make?
Good question.
The radial only goes up for 4 feet and back down for 4 feet.
That is exactly like adding a 4-foot shorted stub in series with the radial.
All that worry about induced current in a 4-foot
n be heard with ease during the
> day.
If any of us **really** had an antenna as sharp as a long Yagi, we'd need 16
or more antennas to cover useful directions.
That's pretty typical behavior for a properly installed Beverage no matter
what the location, unless yo
Just an out of the box thought...
Anyone guess what would happen if the radials going over
the wall were coax shielded ?
Signed,
Anonymous :-))
>>>
I wouldn't sign that either, given the fact it is impossible to shield a
conductor going up over a wall without nearly perfect grounds on each side
f the coax, because we all know a
feedpoint always has the same current on each side if the coax is not
radiating.
Of course some people write entire articles about Kirchhoff not applying to
RF, but we know that isn't true if we understand displa
d excessive inductance and use minimum
size chokes in RF applications.
http://www.w8ji.com/rf_plate_choke.htm
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
of displacement current. Inclusion of displacement current
makes Kirchoff's laws applicable to open ended antennas and time-varying
charges.
We seriously handicap ourselves when we think Kirchhoff's laws are only
applicable to closed dc circuits.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
://en.wikipedia.org/wiki/Displacement_current
Without displacement currents, Kirchhoff's laws cannot be satisfied in AC
circuits involving capacitances, either lumped as a component or distributed
along conductors.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
milar for many years. :-)
> It can be peeled off and I've always found the solder joint just as clean
> as
> it was when it was first done even after several years.
Same here.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
ed
only to dc circuits is like thinking Ohm's law applies to dc circuits only.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
hat isn't even a balun
is described.
This is a hobby without much peer review, and yet we expect people,
articles, or books we hold in high esteem to be right 100% of the time. This
doesn't mean they are worthless, just that we need to understand things are
not flawless.
73 Tom
_
tested" in the
model for sensitivity to changes, include feedlines, and why we really need
to confirm in the real world.
Without matching and feedline losses, and without common mode current
problems, we can design some pretty unique antennas. :-)
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
Hi Bill,
> Tom, it's worth adding to this that trying to make current measurements in
> the ground using 60hz is pretty useless for another reason: induced
> currents from the ac power system (especially in north america). 60hz will
> be present on just about anything -- you&
middle of a segment, which isn't as
good for this exercise, then use the maximum odd number of segments. On a
one wire 160 dipole of #16 that's about 475 segments. In that case the error
is about .001 amperes out of 1 amp, but a split current source is the better
thin
t tell us efficiency, and since we all
should know the sum of currents at each terminal of the two terminal
feedpoint has to be exactly the same (unless Kirchhoff law is a joke), and
since field strength was never measured, the entire article is a puzzlement
to me.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
So gently getting back to the topic of the original post which was:
Getting thoughts on relatively simple and relatively inexpensive
portable 160 m antenna, potentially deployable by one person, that
allows for flexibility and somewhat predictable tuning for use on modest
Dxpeds or rare location in
what exact T2FD design, loss
(efficiency) varies significantly with frequency and some frequencies will
be pretty sour.
The nice thing is almost anything can work DX when conditions are good.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
blications without proper technical review process and error
correction are the real problem, not the overall value of the overall
contribution.
The ARRL Handbooks have very few mistakes because they have a good review
process. Not because of any difference in author qu
n that silly idea.
http://www.w8ji.com/radiation_resistance.htm
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
cribe for 160 in Bill
> Orr's (W6SAI) firsts handbooks.
Just be aware Orr had a consistent mistake in his articles on folded
antennas. He claimed folding reduced ground losses by significant amounts.
I'm not sure where that idea started, but using a folded element doe
, because once out of
the antenna it is gone.
The only possible way to measure efficiency change is to measure field
strength.
People who measure feedpoint resistance changes while changing radials or
ground systems and think they know loss changes
e
was doing something wrong with the space available. They somehow
concentrated E or H fields, or did things to directly conduct current into
soil at one small point.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
Hi Guy,
> This is a non-issue, Tom.
I think it is a critical issue, because it demonstrates the difference
between EM radiation and induction fields that only store and return energy
to the system.
> It stems from what I meant when I said "cancel fields".
>
> Appare
> Completely agree, but you didn't say how to get past the garden
> committee. :>) 73, Guy.
Thin wire or move.
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
ear the radiation field.
I think a test like this shows the difference between EM radiation, electric
induction, and magnetic induction fields.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
twenty
50-foot radials on the ground are the same or better.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
r used the vertical**, to fall out of love with the high dipole.
If we only used the dipole during any one contest, and could not track the
rate with an instant antenna change, I'm sure our rate would go up year
after year. This is because scores overall have
esign plan called for. Have so much
distributed loss voltages never get high.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
the field
reaches the antenna end 100 feet away, why would it not reach earth?
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
cause they have no electric field, and can be mountyed almost
anywhere without much loss. Now it seems we have a conflicting idea that a
magnetic field null eliminates ground losses.
I hardly know what to believe. :-)
I think what we are really going to find is there are many ways
> Elegant analysis, Tom. Thanks. I looked at Guy's very well done piece
> in the National Contest Journal (the one timed for reading on the
> airplane going to Dayton) and wondered why a serious common mode choke
> would not work.
Thanks, not really so elegant though.
Any c
easured one of these systems in a meaningful way
against a proper reference antenna?
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
d be much more
effective than the $200 commercial chokes I have. :-)
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
he radials,
along with a few ground rods on the cable shield on the shack side of the
choke, would be more reliable and easier to implement.
No matter what we do, differences will be very small unless we do something
wrong. There just isn't any magi
> Man, I don't know, Dave. How long have they been selling those carbon
> balls
> for that purpose?
I've never seen a carbon ball in a lightning gap application. I'd have to
see a few after being in action a long time before trusting them.
Broadcast stations use hard metallic balls, as do elect
- Original Message -
From: "Mike Waters"
To: "topband"
Sent: Friday, July 27, 2012 11:33 AM
Subject: Re: Topband: Spark gaps
>I don't think carbon balls are suitable for lightning protection.
I agree. The last thing we want is high surface resistivity, unless we want
something to he
Has anyone looked at, or looked for, cheap electric fence gaps??
My system copper pipes near tower legs work great for me on rigid towers, I
can bend them so they spring away from the tower and then slide an inner
pipe in or out to set gap distance. I'm thinking of gaps for wire antennas.
Maybe
My Mistake:
> To get 30 watts of heat with 226 ohms reactance, Q would have down near
> unity. No one makes a coil that bad.
I misplaced a decimal. Q would have to be near ten in the coil with 226 ohms
reactance and 1500 watts to make 30W heat, not near 1.
The other numbers are correct. A Q of
> 30 watts is correct for 1500 watts in a 50 ohm system and a coil Q of 226.
>
> The power loss is 0.1 dB and the coil temp rise is around 20 deg C.
No, it isn't.
1500 watts is 273 volts into 50 ohms.
If Q is 226, and reactance 226 ohms, Rp is 51,077 ohms. 273 volts is 1.46
watts heat.
To get
4 inches on a 4 inch form. You could use #12 wire Teflon
insulated, and have a Q of maybe 300 or so. Again less than 1 watt heat out
of 1500.
Personally, I'd use #12 or 14 Teflon on some old PVC pipe.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
s are the inductor Q would be in the
hundreds, so dissipation would be negligible.
73 Tom
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
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