Hi, Bjorn
Well I would expect that moving the loading coil higher would be more
beneficial than improving the top loading spokes, as it would move the high
current portion of the antenna higher aboveground (the radial) and there
would, hopefully, be less loss In the loading coil by having it in a
How much I can improve by moving the coil up. What improvement should I
expect if center loading at about 7 meter? How about moving the coil all the
way up to the top loading spokes? Is it worth the effort? (the pole won’t
support much up there).
The coil does not do much at all to current
2.) #10, ignoring connection imperfections, has about .01 ohms per 10 ft.
That's up to 0.2volts with 20 amps of power supply loop current.
Not a problem unless you have bonded DC- to the power supply chassis.
Bingo.
Virtually EVERY piece of gear has a bonded negative to chassis. The whole
Hi, Bjorn
Well, I can't argue with JC. With my first ever inverted L for 160, I had
similar experiences as did his friend, AA7JV with; submerged radials. In my
case, the inverted L was on the dam of a lake behind my house. Not salt
water, of course, but the lake had been treated with some amount
Good morning all.
It appears I was duped two days ago.
The apparently real FT5ZM just showed up 48.5 hours later, but too late for
me. The sun was already 10 minutes in the sky when the very weak signal was
heard at this QTH. The NA west coast is calling right now but I have not
heard any
That's not entirely correct... Triplen harmonics are created by non-linear
loads, but the voltage developed on the neutral as a result of them is a result
of voltage drop between the source of the problem and the return which will
be one or more utility transformers. The farther you are from
One additional point about this that I might not have expressed in enough
detail.
When a top hat with significant capacitance compared to distributed
capaciatnce along the radiator is involved, current tends to become very
linear throughout the radiator no matter where any loading inductance
And our home and ham station grounds, when properly bonded to the service
entrance, WILL share current with the utility system. I see about 7 amps
at home that comes from the utility (but I have a ground ring, lots of
rods, probably 500+ feet of copper in the ground and a well casing). It's
On 1/29/2014 5:15 AM, Tom W8JI wrote:
2.) #10, ignoring connection imperfections, has about .01 ohms per
10 ft. That's up to 0.2volts with 20 amps of power supply loop current.
Not a problem unless you have bonded DC- to the power supply chassis.
Bingo.
Virtually EVERY piece of gear has a
K9YC writes:
There is no problem with V- bonded at load equipment (the rig). The problem
is bonding at the power supply, and that is EASY to fix
-- indeed, many (most?) power supplies are built either with V- NOT bonded,
or with nothing chassis-referenced and a removable jumper
at the
On 1/29/2014 9:12 AM, Shoppa, Tim wrote:
Insulated by paint seems like a very poor idea. It's like someone thought my boss
told me to do this, I don't think I it should be done, and if it isn't worth doing then it isn't
worth doing well:-)
Oh -- I'm certainly not recommending it, nor am I
I bought my Astron SS-30M in 2000 and shortly after found the V- tied to
chassis, which I removed.
73, Gerry, K8GT
On 1/29/2014 12:12 PM, Shoppa, Tim wrote:
snip
Lifting the ground connection to V- is a very common modification to
Astrons and some sources (e.g.
Jim,
Asking customers to modify equipment, which might also include adding ground
studs to computers, is just silly when the entire issue is solved with audio
line isolation in the interface line.
There is no problem with V- bonded at load equipment (the rig). The
problem is bonding at
Triplen harmonics, in most facilities, are caused primarily by lighting
ballasts and electronic (rectifier-input) power supplies. The newer switching
power supplies have a power factor controller in the first stage that acts
something like a current regulator preceding the actual switching
On Wed, Jan 29, 2014 at 07:54 AM, Tom W8JI wrote:
How much I can improve by moving the coil up. What improvement should
I expect if center loading at about 7 meter? How about moving the coil
all the way up to the top loading spokes? Is it worth the effort? (the
pole won’t support much
The discussion is about the placement of an additional loading coil and its
influence while the radiator is already loaded by a capacitance hat.
So who spreads misinformation?
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Yuri
Blanarovich
Here we
Thanks for the update from someone still working in that part of
industry. Yes, PF correction was mandated in EU something like 10 years
ago. It's good news if this ripples back to our continent, even if our
electrical codes haven't addressed this issue. .
That said, as long as
The author points out (correctly) the tempco issues with oil dielectric.
Still I am intrigued by the thought of a remote tuning capacitor via hydraulic
tubing :-). The capacitor plates could be as simple as two concentric cylinder
conductors with appropriate spacers. I betcha crud collecting on
Yes no doubt, it seems if a persons personal agenda precedes their
ability to read with any comprehension on this reflector so many times,
here we go again.
The discussion is about the placement of an additional loading coil and its
influence while the radiator is already loaded by a
I have an omega matched 120 foot tower and I apparently have a bad vacuum
variable capacitor. Upon applying more than about 300 watts, the SWR goes off
scale. Tuning it out and trying again, yields the same thing.
The question is which capacitor is the culprit. These are surplus Soviet caps
All,
I apologize for briefly QRMing the FT5 this evening. Mistakes were made;
buttons were pushed. I will try to pay attention in the future.
73,
geo - n4ua
_
Topband Reflector Archives - http://www.contesting.com/_topband
I have an omega matched 120 foot tower and I apparently have a bad vacuum
variable capacitor. Upon applying more than about 300 watts, the SWR goes
off scale. Tuning it out and trying again, yields the same thing.
The question is which capacitor is the culprit. These are surplus Soviet
caps
Recent success here with 23-foot-high W8JI-style short receiving
verticals in a 4-element broadside/endfire array using variable phasing
has led me to make plans for other sets to cover additional directions.
To maximize distance from existing and potential noise sources, and to
allow for
Thanks Steve:
Not bad - I may try that ! :)
The question in my mind was if there was an arc outside the caps, why would the
SWR change ? Anyway, I may be missing something. I haven't been inside the cap
box at the tower for many months so I'll get into it - may be something easy.
73, Jamie
On 1/29/2014 6:25 PM, Jon Zaimes AA1K wrote:
I've read of the 36-foot-high base-loaded elements ON4UN described in
his book, and understand these would have a slightly narrower bandwidth
than an element with top-hat wires.
But what about an element loaded with a coil at the center or at the
Subject:Re: Topband: Submerging variable caps in oil as substitute for vacuum
variables
The author points out (correctly) the tempco issues with oil dielectric.
Still I am intrigued by the thought of a remote tuning capacitor via hydraulic
tubing :-). The capacitor plates could be as simple
Jamie,
The VSWR would change because the arc would change the impedance at the Arc
point. From perhaps several hundred or thousand ohms to
near Zero during the Arc..
73, Price W0RI
Thanks Steve:
Not bad - I may try that ! :)
The question in my mind was if there was an arc outside the
Amen Merv,
You hit the nail on the head ! !
73 Price W0RI
Yes no doubt, it seems if a persons personal agenda precedes their
ability to read with any comprehension on this reflector so many times,
here we go again.
The discussion is about the placement of an additional loading coil and its
28 matches
Mail list logo
