It is also my experience that stations in China and Southeast Asia in general
do not hear well at all on the low bands. One exception is BG2AUE. I have
worked him multiple times on 80m CW from my QTH in the Boston area. He hears
extremely well on 80. Every single time I've worked him there,
Congratulations Steve for this epic contact! As already pointed out, much of
the difficulty is the very high level of QRN on Ross's end. He gets almost
daily thunderstorms. My experience coincides with what Dave, W0FLS, said. The
most favorable conditions to work 9M2AX are around the
If you are going to use the NCC-2 to null a nearby in-band transmitter, I think
it's very likely that the NCC-2 will get overloaded by the extremely strong RF
and not be usable. I've tried this before and found that to be the case. In
fact, I designed my own totally passive nuller to get
I heard them a couple nights ago on 160 CW, around 2330Z, roughly an hour
after local sunset in W1. They were actually quite strong on peaks but
there was deep QSB that took them down to almost nothing. They seemed to be
having trouble hearing. I heard them come back to N1DG but all the other
Another tool I've found indispensable for setting up and troubleshooting phased
vertical RX arrays is a two-port VNA. I use an Array Solutions VNA-2180 (now
discontinued) for critical measurements. I also have a NanoVNA H4
(https://nanovna.com/) which is a very "affordable" VNA that can be
Here in the Greater Boston area, the signal peaks from the southwest on my
8-circle array. It's not real strong, varying between S4 and S6. I can tell
there is some audio in there but it's not strong enough to identify.
73, John W1FV
-Original Message-
From: Topband
The WD8DSB mini-flag truly is a fantastic RFI-hunting tool. When I saw the
original article in QST, I recognized immediately that this was a great
"invention" by WD8DSB. Like many of you, I deal with quite a bit of man-made
RFI on 160m, so I bought one of the very first ones sold by DX
Here is additional information on the 9-circle low-band receiving array. It
was originally designed for operation on both 160 and 80 meters.
It was based on a couple articles I wrote for NCJ in the September/October
and November/December issues in 2011. The design was turned into a set of
> So how is the QRN doing over there now? Any likelihood of 160m activity
from
> the USA soon?
>
> Roger G3YRO
The QRN on the East Coast is still fairly high most evenings, but there is
propagation to Europe. OK1CF is on regularly and is usually Q5. Also a few
G's have been heard recently with
Some evenings I hear noise-like transmissions, approximately 3 kHz wide,
around 1860 and 1900 kHz that appear to be originating in Europe. I presume
they are not amateur signals. On European SDR's they are quite loud and
operating continuously every day. I find they are actually useful as
Even in a quiet rural location, the limiting noise on 160 will be external
atmospheric noise. Improving RDF will generally improve your signal/noise
ratio against the atmospheric noise. There are exceptions when there is a
source of high noise, like thunderstorms, in the same direction as the
I have a low dipole, about 10 feet high, that I use as an alternate receiving
antenna on 160. My main receiving antenna is an 8-circle array of short
verticals. The vertical array is almost always much better for DX, but once in
a while the low dipole is better, sometimes dramatically so.
EZNEC is correct. Adding more radials, even long ones, in a specific
direction won't preferentially favor the direction in which the radials are
added. It will help raise the overall efficiency of the antenna to a
degree, depending on how many radials are already in place, but any
improvement
In the case of the YCCC 9-circle array, which I designed, common mode
suppression is deployed at both the antenna ends of the feedlines and at the
combiner where the antenna feedlines come together. The YCCC feedpoint preamp
already includes common mode suppression, so additional feedline
You can make a feedline choke with snap-on ferrites as follows: wind 4
turns of the feedline through 5 snap-on cores of Fair-Rite part #0431176451.
The core has an inner diameter of about 3/4 inch and 4 turns of RG-6 is the
limit of what will fit in the core. However, using 5 cores will provide
On 160 and 80, I have an 8-circle vertical receiving array. On very long
paths, it is not uncommon to see skewing. The most common example is the
path to JA, where the direct path heading should be about 330 degrees from
my QTH in New England. However, for the last couple winter seasons, when
I have the DX Engineering preamp that I use with the DX Engineering portable
flag and can confirm the 4.5 dB noise figure. Using the methods I described
here in an earlier post, I measured the noise figure as between 4 to 5 dB.
Also I measured the gain (S21) from 0.1 to 30 MHz with my VNA-2180.
ebruary 25, 2021 10:39 PM
To: topband@contesting.com
Subject: Re: Topband: FW: The WD8DSB mini-flag antenna (LONG!)
On 2/25/2021 5:16 PM, John Kaufmann via Topband wrote:
> The P3 averages power, not amplitude, so using longer averaging times just
> smooths the display and doesn't reduce rando
, 2021 8:03 PM
To: topband@contesting.com
Subject: Re: Topband: FW: The WD8DSB mini-flag antenna (LONG!)
On 2/25/2021 2:29 PM, John Kaufmann via Topband wrote:
> The P3 noise measurement bandwidth was about 100 Hz in my measurements.
I hope that everyone realizes that setting a high va
The P3 noise measurement bandwidth was about 100 Hz in my measurements.
Quoting from the P3 user's manual, "the effective bandwidth of the P3 is
generally one display pixel, which is approximately span / 450. I used a span
of 50 kHz, so it comes out to 111 Hz. Because the relationship is
we probably should move this discussion
over to the RFI Reflector or e-mail me direct.
73,
Don (wd8sb)
On Tue, Feb 23, 2021 at 1:26 PM John Kaufmann via Topband
wrote:
Some of you may have seen the article by WD8DSB in the latest issue of QST.
I believe WD8DSB is on this reflector
As a follow-up to my original post, here are a few additional comments.
Don, you mention that you designed the mini-flag for a deep null off the
back at low elevation angles, which is entirely understandable. As I said
in my earlier post, the null is very pronounced in the AM BCB on local
Some of you may have seen the article by WD8DSB in the latest issue of QST.
I believe WD8DSB is on this reflector. His article describes a mini-flag
antenna that can be used for direction-finding. The neat thing about this
antenna, besides its compact size, is that it is unidirectional and is
This antenna was clearly working well at UA2FW in the recent CQ 160 contest.
When I listened on the band, UA2FW was, by far, the strongest signal coming
out of Europe in mediocre conditions. Normally northern Europe, including
UA2, is at a disadvantage in terms of propagation to the US. Also,
Hi Charlie,
What you see in your TDR sweep of the RG6 is absolutely normal. I've seen
exactly the same thing. The rise in apparent impedance with distance is caused
by the loss in the cable. If you had a lower loss cable, the TDR trace would
be flatter. As long as you don't seen any
We got a piece of the action, too, in New England. I worked JH1HDT, HL5IVL,
and VK6LW just before my SR. HL5IVL peaked up to 579 right at SR. We only get
propagation to HL very infrequently here in W1. JA7BXS was in there but he
first fired up on the disturbance on 1825 and was being
I have two receiving antennas on 160: an 8-circle vertical array and a low
dipole up 10 feet. I have been noticing that in the first part of the
evening, the dipole often hears Europe as well as, or nearly as well as, the
8-circle. This appears to indicate that the signals are arriving at
Here in the Boston area it was peaking from the SW on my 8 circle array.
73, John W1FV
-Original Message-
From: Topband [mailto:topband-bounces+john.kaufmann=verizon@contesting.com]
On Behalf Of w...@w5zn.org
Sent: Friday, December 11, 2020 7:24 AM
To: David Raymond
Cc:
I have the RPA-1, the predecessor to the RPA-2. It's an outstanding preamp
with a low noise figure and very high dynamic range. I'm sure it would make a
fine BOG preamp.
73, John W1FV
-Original Message-
From: Topband [mailto:topband-bounces+john.kaufmann=verizon@contesting.com]
I use the VE7CC node for spots. You can filter out FT8 spots on VE7CC via the
'set/noft8' command.
73, John W1FV
_
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
For signals that arrive from directions that are in between the main lobe
headings of a 4-square, you will lose up to a few dB of S/N compared to having
8 directions. Whether that matters to you is purely a personal performance vs.
complexity/cost decision. If 90% of what you work is covered
Inverted vee dipoles do produce some vertically polarized radiation off the
ends. However, that vertical component has maximum gain at zenith, i.e.
straight overhead. It does not contribute to any significant low-angle
radiation. You can see this by doing an antenna model.
73, John W1FV
Steve,
An alternative is to do the cancellation with all passive circuitry. You
can find some designs on the Web but you'll have to build them yourself. An
example (one that I built) is this one from WA1ION:
https://www.pa4tim.nl/wp-content/uploads/2011/02/passive_bb_phasing.pdf.
The drawback to
tmospheric noise
have to go up by at least 3dB.
I think I have this right, John, but feel free to shoot holes in it if I
don't. I know thinking about it made my head hurt.
73, Mike W4EF
On 3/12/2020 4:37 PM, John Kaufmann via Topband wrote:
> To assess the impact of amplifier circuit noi
To assess the impact of amplifier circuit noise in "active" receive arrays,
we only need to be concerned with the contribution of amplifier circuit
noise relative to atmospheric noise. The details of how signals are phased
in any particular array do not matter. The objective is to keep the
Lee,
I think you are confusing voltage and power. For incoherent sources like
amplifier noise, the voltages of multiple incoherent sources add in a
root-sum-squared (RSS) fashion. The voltage of the sum of eight incoherent
sources is square root of eight times a single noise source, assuming
As the designer of the YCCC high impedance feedpoint amplifier, let me
address some issues related to the design of the YCCC amplifier as well as
feedpoint amplifiers in general. If you don't want to read a lot of
technical gobbledygook, please disregard this message.
The YCCC uses an AD8055 RF
It's also very strong in the greater Boston area. The signal is very steady
with only a few dB of very slow fading. I get a heading of roughly SE,
which would put it towards Cape Cod or Rhode Island, but it could be
anywhere between E and S. It doesn't exhibit strong directivity on my
8-circle
Greetings Topbanders,
Matt, KC1XX, is spending the winter in HI3 and asked me to relay this
message to all of you. He is on the air as HI3/KC1XX but is experiencing
terrible line noise at his present location. He hears lots of stations
calling him on the low bands but he is having great
I'm looking for a source for durable ladder line for making two-wire
reversible Beverages for use at the KC1XX contest station. In the past
we've used the line sold by DX Engineering but over the years we've found
that the plastic spacers between the wires become brittle and break off. It
may be
40 matches
Mail list logo
