Don's directional loop should significantly reduce my tracking time for most
common switching noise in the neighboring area. I currently use a National RF
loop + preamp with an SDR-IQ receiver strapped with Velcro to a notebook PC.
The SDR-IQ is powered from the PC's USB port.
It's very
r parallel -- to a nearby T-top the impact
on the performance of the 40 meter Yagi is severe.
Been there. Done that...
73
Frank
W3LPL
- Original Message -
From: "Paul Christensen"
To: topband@contesting.com
Sent: Friday, February 28, 2020 12:45:19 PM
Subject: Re: Topb
I would hate to give up the efficiency of an over-resonated T, even if field
strength isn’t significantly better than an L design. I think two design
issues help to avoid pattern distortion to nearby HF Yagis.
First, as Frank suggested, keep the length of the horizontal T wire
non-resonant
>"With respect to current distribution with the lowered resonance -- N6BV
modeled it in his NEC-4 licensed software, and found no increase in the far
field compared to a resonant antenna."
Looks like I accidentally cross-posted to the TowerTalk list, so I'll bring
it back...
Jim,
I didn't see
-feeding an antenna. The side walls are sturdy and many
models have a gasketed rubber seal that forms around the lid's perimeter.
Paul, W9AC
-Original Message-
From: David Olean
Sent: Thursday, January 9, 2020 4:15 PM
To: Paul Christensen ; 'topband'
Subject: Re: Topband: de
> does anyone know of a HV (20KV) capacitor with a value of approximately
500 pf that has a NPO value?
Once you get above about 100pF, NP0 options are very limited. Be mindful of
the RF current magnitude in the application. Small doorknobs can heat and
change in value. In fact, I am dealing
Here's a DIY article from Jeff Welton at Nautel:
http://support.nautel.com/tips-n-tricks/how-to-make-roll-your-own-carbon-ball-gaps/
The carbon spheres that Jeff mentions are made by Ross Engineering. Not sure
of the cost, but may be worth considering:
Steve,
I recently ran into an identical problem with an Alpha 89 amplifier. A pair of
0.01 uF/100V caps had failed on the plate choke clapper arm relay. The caps
are used on the relay coil as an RF bypass to ground. In time, RF caused the
caps to become leaky. With 1KW RF applied on some
>What I do not understand on all this is. If the station is running on
itself UN-attended. Is that just not even legal. Never mind ethical?
Fully automated does not always mean unattended. In the rare instances I am
on FT8 and it's automated through Quick Macros, I may be parked on the side
of
>If I can set up my station on ft8 and have it run automatically and collect
>new entities...
If you want to fully automate FT8, there's a presentation available on YouTube.
It only requires installing Quick Macros (QM). No hacking to the core program
is required. During my setup, it was
No issues hearing 7P8 at my local SS yesterday but the QSB fades were very deep
and long. Possibly the fades weren't as bad later in the evening?
Paul, W9AC
-Original Message-
From: Topband On Behalf Of
daraym...@iowatelecom.net
Sent: Thursday, March 14, 2019 12:58 PM
To:
>"This trend began rising dramatically during November, 2018."
Sorry, meant, November, 2017.
Paul, W9AC
_
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
>"However going to reversebeacon.net and entering my callsign - I can find
out that I am indeed getting out and the band is open..."
If PSKReporter is to believed, total global CW activity across bands is now
less than 1% of FT8. For example, look at the report for the last 12 hours
(0.4%).
>"Soon it may be computers working computers with minimal operator
supervision."
Already happening with Windows macro commands. Anyone who works me in the
sparse instances I'm on FT8 is making a fully-automated contact. When one
FT8 contact is complete, macros start another. I may be in the
>So, now we're (apparently) recommending he cut back his already minimal
radial field..uhhh, really Wes?
I agree with Wes' assessment -- as well as him questioning why Rr would
increase with an increased number of radials. If Rr is changing
significantly with the increase, then something else is
>"I would think adding radials would lower the Radiation resistance. Also,
the SWR curve should narrow as ground losses are reduced; since the effect
of ground loss resistance swamping the results lessens."
The base resistance, not the radiation resistance is lowered by adding in
radials. At
>"Older generation N connectors with floating center pins are highly
problematic because its difficult to install the center pin with proper
depth and axial alignment."
Lived it. To support myself during college, I was chief engineer at an
AM/FM station in Dekalb, Illinois. One winter morning,
I think the primary flaw of the PL-259/UHF connector is that shield
connectivity is strictly a function of thread tightness. There's no inner
sleeve to maintain good electrical contact of the shield with any loosening
of the connector plug. Otherwise, I have no issues with either connector up
-
From: Topband On Behalf Of Paul Christensen
Sent: Sunday, October 21, 2018 5:02 PM
To: topband@contesting.com
Subject: Topband: FW: Isolated F81 F Barrel Connector
Thanks for all the replies. I failed to mention that the plate is being
designed in Front Panel Express (FPE) software. I
e:
Can't you just use a non-metallic plate?
-Steve K8LX
On 10/21/18 15:08 PM, Paul Christensen wrote:
> Google isn't my friend today...
>
> I am looking for an isolated "F" barrel connector, commonly known as the
> F81. I am designing an aluminum interface plate for use with
Google isn't my friend today...
I am looking for an isolated "F" barrel connector, commonly known as the
F81. I am designing an aluminum interface plate for use with a Hi-Z
8-circle receive array. The panel will contain multiple F81 barrel
connectors that attach to the side of a large PVC tool
I ran the same model in 4Nec2 as below but changed the hat from the traditional
two wires to four, spaced 90 degs. Complex base Z is near 16+j0. Even though
two symmetrical top-hat wires produce little radiation, four wires result in
wires that are only 24 ft long to achieve resonance --
Jim,
Just my 2-cents. Here goes...
First, NEC 4.2 160m "T" modeling shows very little advantage of having 4
top-hat wires instead of just two. The azimuth radiation pattern is almost a
circle in the horizontal plane with two wires since very little field strength
is radiated from
>"The cost savings they are talking about amounts to very little. It would
>cost a helluva lot more to dismantle them completely. Besides TIME and freq
>standards, WWV provides for a myriad of other features."
Seems like a great opportunity to spin-off WWV/WWVB to one of Colorado's
"NIST will discontinue the dissemination of the U.S. time and frequency via
the NIST radio stations in Hawaii and Ft. Collins, CO. These radio stations
transmit signals that are used to synchronize consumer electronic products
like wall clocks, clock radios, and wristwatches, and may be used in
> And what do you compare your fancy GPSDO or rubidium reference standard to
in order to make sure they have not encountered a major
> failure?
Several options: (1) CHU is still operating on several HF frequencies that
reasonably cover North America; (2) In the U.S., AM broadcast stations are
Tony,
Instead of a wire, consider using a short 1/2" wide copper strap from the
radial plate up to the coaxial input connection on your box.
I think you made the right choice in using a separate box for the feed. I
recently did the same with NEMA 4x4x2 boxes mounted on a 2-inch pipe. The
>"Another technique that is often used for matching is to make the wires much
>longer than resonant (that is, resonant around the top of the BC band), so
>that the feedpoint Z is 50 +jX ohms (that is, inductive) on 160M, and tune the
>capacitance out by adding a capacitor of equal value in
>"The reason is that the standard DA ground system as far as I know, has
always involved strapping radials to a copper strap running along the line
of radial intersection, clipping off the radial wire that runs past the
strap."
Unless there's modeled or measured data, that's the "conventional
Dan and all...
I am in the middle of constructing 4-squares for 160m and 80m. One element
of each array is up and operating. A decision must be made concerning the
layout of Teflon-insulated radial wire and whether to run a bus wire/strap
at the intersection of overlapping radials. It may not
Steve,
Thanks. Word wrap prevented me from opening the file with your e-mail messages
but I copied the full URL into my browser and it did open. Possibly he is
using WebSDR more on 160m-80m, but from my experience on 40m, his operating
behavior -- and that of others calling him doesn’t seem
No doubt some ops are using WebSDR on receive, but in this case, I am skeptical
of the skepticism. Here's why:
I routinely work VU2GSM on 40m GL-LP in the early morning hours on a 210-degree
bearing from FL to VU. He is consistently S9, peaking +10 dB on my Elecraft
K3. The remote station I
Brad,
If you use an LED with a dropping resistor across the coil to monitor relay
status, then you must use a fly-back diode. The coil of the type you're
using will produce substantial EMF as power is removed and the coil field
rapidly collapses. The collapsing field will produce E-I beyond the
> "I second TLDetails. TLW, not so much."
TLW also contains a powerful tuner modeling tool, allowing for the quick
design of hi-pass-L, lo-pass-L, and T networks. Once the complex line input
Z is calculated by TLW, the result can be input into the tuner model to
transform the complex Z into
David,
I think the best and quickest way to understand and observe line impedance
transformations is to model it using software. Two popular programs are TLW
and TLDetails. TLW is bundled with the ARRL Antenna Book. TLDetails can be
downloaded here:
http://www.ac6la.com/tldetails1.html
It
My NCC-1 was purchased from DXE back in 2008-2009 and has never been used.
Apart from changes to the manual, are there any evolutionary hardware changes
or modifications?
Paul, W9AC
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bob K6UJ
Sent:
>"The KPA does have diodes, but I don't know why the KPA diodes seem to make it
>and others don't. Maybe not stressed as bad switching into an open load, which
>might be the real culprit that folks don't want to admit to."
The KPA500 has substantially less field operating time compared with the
> "Where do you buy stuff for beverage like 470 ohm non carb resistor for
terminating and cores for 9:1 in US ?"
Ohmite and IRC/TT still manufacture non-L, carbon composition resistors. If
there's a reason to avoid carbon composition, Ohmite and KOA manufactures
ceramic composition resistors in
Last weekend, I noticed a high level of noise on the HF bands, especially
160m through 40m. The noise was classic switch-mode. The switching
frequency is 84 kHz.
Yesterday, I went on foot with my RFI locate gear and located the source in
under an hour, about a 1/4 mile away. You can read
That's one reason why I like to augment a NEC-required mechanical connection
with silver-solder. The mechanical connection will degrade with time but it
will take significantly longer for a silver-soldered connection to degrade,
absent some really acidic soil condition.
Local code here now
* ”I've not heard anyone talk about doing a proper clamp, and then protecting
the proper clamping by silver soldering over it all. The obvious disadvantage
is that changing out the connection becomes interesting, as in replacing the
ground rod.
Not sure how you reached that conclusion.
>"The favorable SDR averaging doesn't apply when the RF voltage at the receiver
>input is dominated by one huge signal, and if that signal exceeds the
>capability of the ADC in the radio, overload can definitely occur. So,
>although I believe that nearly all manufacturers will soon migrate to
> "I've replaced all of the SMPS blocks that came in my door with vintage
linear supplies (and some are vintage linear supplies float-charging
sealed lead acid batteries. 73, Jim K9YC"
Same here. For wall-mounted power supplies, Jameco has an excellent
selection of regulated and
FYI - The S-QSK boards are now spoken for. Thanks for the replies.
Paul, W9AC
_
Topband Reflector Archives - http://www.contesting.com/_topband
Another option for "front end" sequencing control involves the use of a
microcontroller to time R=>T and the the reverse switching events. For the
past two years, I've been using an Arduino Nano-based controller to manage
amplifier switching as well as a PIN diode T/R switch to silently
Do you use a earth tester? Which brand do you know is very good and
accurate to consider?
Jorge,
If you can, try and find a clamp-on earth tester rather than the type that
relies on the fall-of-potential method with electrodes. There are several
good clamp-on units by Megger, Fluke and
“Perhaps a few words on how you joined the rods would be useful here.”
We used TB/Blackburn 60CNT2 non-threaded couplers to join the ground rods. A
compression fit is used to join the rods. The rods and couplers were obtained
from our rural electric company.The utility also supplied
Rich,
Have a look at 1KW 1130 AM on Hilton Head Island, SC (WHHW-AM). At 12 noon
on any day, I can easily ride that signal down the Space Coast of FL and
about 10 miles inland. That's the entire coast of GA, part of SC and half
of FL.
Paul, W9AC
-Original Message-
From: Richard
This is why wide broadcast towers, even 1/2 wave tall towers, can have
reasonably low impedances at the base.²
Agreed. I have found it very difficult to model accurate complex base Z
measurements of wide broadcast towers (i.e., low height/diam. ratio) that
are of the 180-195 degree variety -
Those Hammy Hambone radial plates I have seen advertised are considerably
more expensive than a handful of silver brazing rods and a Mapp gas outfit.
Don,
All good points. A few weeks back, there was a discussion here about the
virtues of using MAPP gas or acetylene with silver brazing rods.
It is not about remote technology or use of or for DXCC, it is the change
into a enterprise carrier service $/min or $/KW.
Now, extrapolate the RHR business model to hundreds of similar paid remote
services, all competing for customers to access what has been free spectrum
regulated by the
'The KEY WORD is the COMMUNICATIONS².¹
Milt,
We¹ve already addressed ³communications.² A definition needs to be added
to Part 97.3. Absent a definition, there is no clear meaning of the term
and is left to interpretation, and abuses of interpretation.
IMHO, it is totally legal per written
If Paul doesn¹t agree with their interpretation, and thinks they
should cease and
desist, that is why we have the FCC, and failing that, the federal court
system of the United States.²
Steve,
I¹m not going to argue the validity of anyone¹s (mis)interpretation unless
it comes from the FCC or
/the-stations/
73
Peter
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Paul
Christensen
Sent: Donnerstag, 5. Februar 2015 17:10
To: topband
Subject: Re: Topband: Foreign stns using NA remotes for K1N
I'm sure you realize this, because people just
On 2/4/2015 7:27 AM, Larry - K1UO wrote:
Could someone tell me the length of top loading wires (4 wires planned)
needed to add to the top of a base insulated 90 foot Rohn 25g tower to
maximize the radiation resistance on 160 meters. I understand there is a
point of diminishing returns on the top
My 160 TX is causing RFI to one of my baseboard heater programmable
thermostats (switches modes, temperature, when I transmit). The
thermostat
has a 2 wire connection to 240VAC in a metal receptacle box that has a
third wire common ground wire. I would like to try bypassing the AC
line.
Can
I've long thought about designing a radial plate that addresses some
significant limitations with currently available product. Specially, every
commercially available radial plate uses single-hole lugs to attach a radial
wire to the plate. The problem is that with upwards of 60+ lugs in
Bifilar winding of power leads is a two edged sword. While it reduces
core
flux from power line currents, it also reduces differential suppression in a
similar fashion. In a tightly coupled choke, the windings simply behave like
a transmission line. It takes a stand-alone choke in each
Commercial transmitters and receivers for 160 meters have long been
available.
To Frank¹s point, here are some additional early commercial 160m receiver
examples:
National SW-3 (ca. 1931 regenerative with dedicated 160m band spread coils)
National HRO (ca. 1935 with sliding 160m coil drawer
When Paul was licensed in January, 1937, the 6L6 was just being mass
produced. The National NC-101X had not yet been designed and the
regenerative SW-3 was still being sold along with the new HRO. Crystal
control had just replaced Hartley, TNT, and TPTG transmitters. Television
was in the
“If you had trouble with an oxyacetylene torch, then I'll bet you used
silver-bearing (tin-copper-silver) solder, which melts at well under 700
degrees.
These are mid-level silver sticks with 15% silver + copper/phosphor and have a
working temperature of 1200-1400 degs. F – but not the 2-5%
The only issue is that solder requires a bit more heat
then the leaded solder.
To get adequate heat when using silver-solder bars, one option is to use a
small acetylene cylinder tank with a single line torch kit. The typical
air/acetylene temperature is about 1000 degrees F higher than
Not sure that I can picture just what you are describing, Paul. Even
though, I wasn't born until 1944, I've explored just about every type of
antenna and I've modeled an awful lot of them.
See the image in the link below:
After rotating the image in your browser, note that the feed to the
Rich,
It's an issue that's not usually seen in the broadcast engineering world
where one frequency is transmitted for broadcast. Typically a transmitter
will fold-back delivered power when its output Z is fixed (e.g., 50 or
70-ohm) and SWR exceeds some predetermined amount set by the
What did they call the teens to 20's antenna that had multiple feeds
coming
down from one end of the flatop to the other?
Both the T and the fanned inverted L were popular on 200m in 1910-1920
just as the single-wire Inverted L is today on 160m. Back then, ops were
obsessed with maximum
from a 12V battery that is floated by a small linear supply. (A year or
so ago, I went through my home and got rid of all the switch-mode crap).
At last count, I have more than a dozen linear supply replacements here.
Some are built into consumer A/V equipment, others are used to power
Maybe I didn't read the right paper.
Like I said, this paper is clearly
not on the same page with what Paul C. said.
Paul, can you point us to the correct paper
to read? Rick N6RK
Rick,
You likely read it right but the report implies too much emphasis on
needing LDMOS devices to achieve
Tom,
Also consider a situation where a solid-state transceiver is driving a class B
amp with, for example, -20 dBc 3rd order IMD -- and that IMD is much worse than
the driving transmitter. In that case ADP is correcting IMD products where IMD
is generated primarily from the amp.
Paul, W9AC
Sorry for the dyslexia. I've been meaning to type APD, not ADP.
Paul, W9AC
Sent from my iPhone5
On Aug 3, 2014, at 10:58 AM, Paul Christensen w...@arrl.net wrote:
Tom,
Also consider a situation where a solid-state transceiver is driving a class
B amp with, for example, -20 dBc 3rd
I read the technical report on Pure Signal and it
sounds like what we used to call a hero experiment
in the research lab where I worked, consisting of a
few impressive results, but with many disclaimers,
and nothing you could productize. What is supposed
to be new is the adaptive part, but it
A quarter wavelength 75 ohm coax working into a 50 ohm load, transforms
the 50 ohm load to 112.5 ohms, non-reactive, as it appears at the end of
the coax next to the transmitter, as previously discussed.
Good so far.
If we place a 50-ohm SWR meter at the near end of the coax, between it
and
As I looked at things over the years, very few people want VNA's that
attach
to PC's, and that market is covered anyway. I thought a 259 revision wth
direct conversion receivers and a wide frequency range, and a calibrate
function, and just basically do what the 259B does now, would have been
Where is a selectivity spec or a description??
73 Tom
Tom,
Apart from the N2PK analyzer, I don't know any published selectivity spec.
The detector minimum res. bandwidth of the N2PK unit is 7 Hz and produces
+4dBm into 50 ohms.
FWIW, RigExpert put together a comparison of analyzers based
I had a look at the matching Rosenberger calibration standards and for the
money, the kit is a bargain. At first, I was disappointed to see what
amounts to only 1% resistive load accuracy. The displayed image on the
website shows a calibration standard that reads about 49.5 ohms. But, the
I shut down all of the circuits in my house other than my shack and it did
not disappear.
Has anyone experienced something similar?
Constantly. You took the right first step and determined that the noise
source is external to your home. From here, the real work begins. Trying
to get an
It is built around the DDS VFO kit sold by N3ZI and amplifier kit from
W8DIZ. Power is 1 W to a 43 foot vertical.
If the QRSS station is operated at the FCC-licensed address, that places his
QTH on a narrow peninsula on the Gulf of Mexico. In one direction, it's
about 700 ft from saltwater.
Ditto on that series Tyco relays. I used them about 15 years ago when
switching line lengths on the W5DXP No Tuner All Band Antenna. That
antenna requires five relays to stretch open-feeder line lengths. They
performed well outside although they were protected from rain with simple
plastic
These transmatches these days T matches just do not have the balls for
160M
running power. They do if the tuner's complex load Z is reasonable. I
melted down a MFJ 998RT arced plates on an MFJ 989B
melted down a 25uH Millen coil, arced wire burned up insulation all with
500 watts :-) I tried
.
Paul, W9AC
- Original Message -
From: Paul Christensen w...@arrl.net
To: topband topband@contesting.com
Sent: Saturday, October 19, 2013 11:44 AM
Subject: Re: Topband: W8ji ATR-10 design 160M?
These transmatches these days T matches just do not have the balls for
160M
running power
The advice I would give anyone is pretty simple. Don't design or use an
antenna that has extremely low or reactive feed impedances, unless you
have no other choice. If you must use one, plan on low efficiency and
other problems.
My conclusion as well but adding more switched C will certainly
So what different bout your tuner, is it like the ATR-10 design?
Nothing special. It's just a symmetrical balanced tuner with a pair of
synchronized roller inductors and a large vacuum variable cap (with a very
small minimum C and large max C) that's switched with a pair of vacuum
relays.
I'm afraid I don't understand how a surge
protector that clips an, e.g., 1KV spike on a 120 VAC line can end up
doing more damage than no protection all. I understand that the
clipped current pulse returns through the ground line and will cause a
voltage spike on the ground, and I also understand
- Original Message -
From: Paul Christensen w...@arrl.net
To: TopBand topband@contesting.com
Sent: Wednesday, October 09, 2013 9:55 AM
Subject: Re: Topband: Best Outlet sttrip
I'm afraid I don't understand how a surge
protector that clips an, e.g., 1KV spike on a 120 VAC line can end up
would rather clamp to neutral where it's still at ground
potential by virtue of the neutral-to-ground bond at the entrance, but not
potentially raise the potential of the branch circuit's grounding
conductors.
Paul, W9AC
- Original Message -
From: Tom W8JI w...@w8ji.com
To: Paul
The standard drop cable is a bonded foil with single braid, it has been
that way since the late 1970's. The current best grade is Brightwire by
CommScope. Any good cable will far exceed FCC specs without a quad shield.
It remained that way with Comcast ATT Broadband at least until 2002 when
Mike,
I rarely recommend YouTube videos, but Belden has produced a 3' 37 second
video promoting their ProSNS line of Snap-N-Seal F connectors. This list is
tightly run, or I would otherwise post a link. Just run a search for Belden
ProSNS.
At 2 minutes into the video, the Belden rep does
This white paper, written by Clarence Beverage may be of interest to the
discussion:
http://www.commtechrf.com/documents/nab1995.pdf
Paul, W9AC
- Original Message -
From: ZR z...@jeremy.mv.com
To: Guy Olinger K2AV olin...@bellsouth.net; Eddy Swynar
deswy...@xplornet.ca
Cc:
Tha's a great topic and I'm sure Frank will add a lot of interesting
information. About twenty years ago, I became interested in the 1921
transatlantic tests and slowly began collecting information. The fall, 1921
issues of QST are a great source as is the Radio Club of America's (RCA)
early
In the vehicle I often like to use an old (i.e. analogue and inexpensive)
spectrum analyser like some of the portable Texscan CATV ones.
As CATV companies have transitioned from NTSC to QAM channel line-ups, high
quality field analysis meters have been showing up on the used market in big
First, they would be fools or have idiots for engineers to have more than
120 radials. The only real reason they use 90 radials or so is it
sometimes gets them out of expensive proof-of-performance measurements.
Or, (1) to compensate for field degradation over the course of several
decades.
Right, typically a couple hundred ohms. Modeling the base Z of a thick
broadcast tower is very difficult with MoM software. Changes in thickness
can result in large base Z changes.
Just to be clear, since the discussion drifted to half-wave radiators, my
comment above was specific to the
AM broadcast band antennas 5/8 1/2 wave tall are rarely used any more.
I noticed a reduction of the tall AM towers starting about the 1960's.
An optimized half-wave design (180-195 electrical degrees) is still the
height of choice for AM broadcasters. There are many factors, including
Most of the reasoning for this unexpected negative result was attributed
to the minor high-angle lobe produced by the 5/8 wave coming back down and
interfering with the main lower angle signal. As a result, those station
who had experimented with 5/8 wave towers usually reduced them to 1/2
Mr. Fry supplies a monolithic, complete fill up to three degrees at some
unspecified frequency over unspecified ground out 2.8 km. The difference
between that and the NEC pattern generated for 1/4 wave over 120 0.4
radials at three degrees elevation is over seven dB. That is a LOT of
fill.
I
The measured MW data looks compelling and agrees with the NEC surface wave
analysis. Even accounting for frequency disparity between the BC band and
160m, low angle field strength remains robust.
Rich, what is the station's operating frequency and approx. soil conductivity?
Doubters may
Excellent work, Cristi. A suggestion for this last part of the analysis.
Rather than look at the vertical angle where the radiation peaks, look at
the field strength at some chosen low angle, like 10 degrees for various
soil conditions. Now, we can see a dB value.
But, we're not done there.
To Rich's point, I created a buried field in 4NEC2 using the radial geometry
wizard and a vertical wire radiator 40m tall, all wires being of #12. The
radial field consists of 64, 0.5 wavelength radials, buried 0.1m deep in
moderate soil conductivity of 3 mS/m. As a bit of a sanity check, the
I've used screens when I needed a wide bandwidth ground system, but never
under other conditions.
Adding a screen or preferably, additional short radials at the base will
assist in stabilizing the resistance component of the vertical radiator and
capacitance across the base insulator as
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?
I recently purchased a copy from the ARRL and it's well worth the $20 price.
Table of Contents:
- Short Antenna Behavior
- A Better Way to Define
The best of the antennas, a Marconi-T with a 66-foot vertical section
over about 30
60-foot to 100- foot radials, had proved relatively ineffective...
Steve,
What was the length of the horizontal T section?
Paul, W9AC
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