Europe is tough in New Mexico, but last evening for about an hour after
sunset (0100Z-0200Z) I worked G3YRO, SM5EDX, and OR18TLS. As often happens,
signals were barely copyable when I worked them, with deep QSB, but got
stronger later, peaking 569-579. W7RH lives in a neighboring state and
always s
Guy, I agree in principle that coax with a stranded center conductor will be
more flexible than coax with a solid conductor, although in applications where
there is mechanical stress on the coax, coax with a solid steel core will be
significantly stronger than its stranded counterpart.
However,
About twenty-five years ago I started replacing many of my PL259
connectors with N-connectors. I did this mostly because my VHF/UHF buddies
convinced me that the impedance bump of an N-connector was less than that of
a PL259. Also, about the same time I started using mil-surplus Transco
rem
Hi All,
I have a 70ft 80m self-supporting vertical, which I've baseloaded to bring
it down to 160m. The antenna is about 800 ft. from my shack, fed with buried
hardline. The vertical has sixty 120 ft radials fanning out over the desert
floor.
When I built the baseloaded inductor I didn't have
On this general topic, I'm erecting a 68 ft aluminum self-supporting
pole (DX Engineering) that is four inches OD at the bottom, tapering to
about 1/2 inch at the top. It is designed as a full size 1/4 wave 80m
vertical. I'd like to use it on 160m. If I add four capacity hat wires
at the top, w
Vic, I've had nothing but bad luck in trying to support long horizontal lengths
of ladder line. In my case, I have two 720 ft bidirectional beverages, which I
initially made of heavy duty commercial ladder line. I supported the line with
wood 4"x4" posts, spaced sixty feet apart, using the littl
I'm always hesitant to challenge anything Jim VE7RF says about amps,
because he's almost always right, but here I have to respectfully
disagree with a couple (not all!) of his points. I, too, call
protective diodes "back EMF" diodes, because their purpose is to clamp
the inductive voltage spik
I think some contest stations had directional receive antennas and omni
transmitting antennas. There were times when S9 stations couldn't hear me at
all, and I suspect they were just listening in a different direction. At
other times, I could work stations just marginally out of the noise.
I noti
Tim is an outstanding ham and a super nice guy, but he unfortunately
inherited the "no schematic" DXE policy when he took his job. He does his
best to provide customer support, which I appreciate, but there's not much
he can do about changing the policy, which customers have complained about
for ye
When controversial topics are discussed on email reflectors, it's human
nature for people to become emotional. However, it is important that
exchanges remain polite and respectful of opposing viewpoints. The list
moderator has the responsibility to step in and curtail inappropriate
commentary. One
Guys, seems to me this topic has been worked to death. Maybe it's time to
give it a rest.
Jim W8ZR
_
Topband Reflector Archives - http://www.contesting.com/_topband
Here, 160m vertical had noise floor this AM of -103 dbm, with beverages (720
ft), about -118 dbm, measured with Flex 6300. No need for a preamp.BTW, 160 was
poor this morning.
Jim W8ZR
> -Original Message-
> From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of C Allen
> Ba
I did some tests a few years ago on unshielded CAT6 (UTP) cable. The
twisted pairs in the cable are rated at 100 ohm nominal impedance, so I
paralleled two sets of twisted pairs together and measured their VSWR.
Surprisinlgy I found the cable handled 100W at 20m, with negligible VSWR. I
thought a
I have the 26m (85.3 ft) Spiderbeam fiberglass vertical, with sixty 30m
radials on top of sandy desert soil. It uses four 7m top hat wires, and is
tuned to 1.820 MHz, where the VSWR is 1.47:1. I feed it with about 300m of
buried hardline. The assembly instructions are clear and the antenna tuned
Steve,
I have two bidirectional beverages (NE/SW and NW/SE), each 720 ft long,
configured in a V-shape. I'm using DXE switching and xfmrs, with the vertex of
the V a 4x4 post. I use additional 4x4 posts spaced every 60 ft along the
length, seven ft out of the ground, with ceramic insulators wi
ndle a volt or
more without overloading their ADC.
73,
Jim W8ZR
> -Original Message-
> From: James Wolf [mailto:jbw...@comcast.net]
> Sent: Monday, October 12, 2015 9:45 PM
> To: 'Jim Garland'
> Cc: topband@contesting.com
> Subject: RE: Topband: ADC Overload
&g
Interesting comments, Steve, and to me quite on the mark. (In an ealier life, I
was a physics prof, though I've forgotten most of what I once knew).
Re the comment by another list member that "there are various distractions such
as the Central Limit Theorem...that don't add much to the discussio
ent: Monday, February 09, 2015 11:54 PM
> To: 'Jim Garland'; 'Lee K7TJR'; Topband@contesting.com
> Subject: RE: Topband: K1N DQRM Tracking Project
>
> Actually ,Jim, the velocity of propagation of radio waves (or light
waves)
> in free space is about 1 foot/nanos
I agree, Lee. Locating a DQRM station involves accurately time stamping the
arrival time of their transmissions, at (at least) three receivers at known
locations. Once the arrival times are known, one can use trigonometry to
calculate the location of the interfering station. Since radio waves trave
I don't remember the article, Charlie, but that's a fabulous idea, and at
first blush it doesn't sound all that hard to implement. One way might be to
set up three receivers at different locations, each with a 10 MHz GPS or
rubidium time base (both inexpensive and readily available.). For each
rece
Guys, I'm not following all this, possibly because I'm confused by Jim's
distinction between "filters" and "chokes," because in both cases they're
just lossy inductors, although used in different ways and for different
purposes.
Consider common mode noise on a simple parallel wire transmission li
Rodents chewed through a set of kevlar guy lines for my Spiderbeam 26m
vertical while I was out of town last week. Down came the vertical, which
broke into three pieces, and when the guy lines fell to the ground, the
rodents ruined them all. Looks like I'm off 160m for the winter. It will be
a big
Mack, I use two DXE bi-directional beverages, each 720 ft long, fed with a
single 300 ft length of direct burial quad shield RG6. The DXE transformers
and relay switching boxes use high quality weather-proof construction. That
said, the ladder line caused me nothing but continuing maintenace headac
Intruders are becoming endemic on all the hf bands, not just top band. Every
morning I hear SSB stations on the low end of 80m and 40m, and the worst of
all are 10m-12m, which have become a nightmare of swishing signals,
carriers, buzzing sounds and illegal CBers. I hadn't realized how bad the
situ
Oops, forgot to attach one of the photos. Here it is.
Jim
_
Topband Reflector Archives - http://www.contesting.com/_topband
barely waves in the wind.
73,
Jim W8ZR
> -Original Message-
> From: Grant Saviers [mailto:gran...@pacbell.net]
> Sent: Thursday, May 01, 2014 1:39 PM
> To: Hardy Landskov; Mike Waters; Jim Garland
> Cc: topband
> Subject: Re: Topband: Beverage wire question
&g
I want to replace the 450 ohm ladder line for my two DXE 720 ft long
bi-directional beverages with two lengths of WD-1/TT field telephone wire.
The wires will be secured only at the ends, but will be suported along their
length by ceramic insulators mounted on 4x4 posts spaced every 60 ft. The
spa
Here in sunny NM, with nothing resembling grass, I just laid my sixty 120 ft
radials on the top of the desert. It's stranded 14 AWG with a brown THHN
insulation that matches the dirt. I figure in a couple of years the
insulation will pretty much be gone, and then it will just be bare copper.
Ain't
I've been using 450 ohm ladder line for my two bi-directional 720 ft
beverages. These are supported on 4x4 posts, spaced 60 ft apart. I'm in a
windy area, and the ladder line requires constant maintenance. I want to
replace it with parallel wires, which run through ceramic feedthrough
insulators sc
He was on top band for two hours this mornig, easy to work from NM. Probably
much harder from KY, but he's a fine operator with good ears on 160.
73,
Jim W8ZR
> -Original Message-
> From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bill
McDowell
> Sent: Wednesday, April 16
I agree completely with Bud's take on the contest. This was my first year of
participating and I found the rules unclear and poorly written.In fact,
until a friend corrected my misunderstanding, I hadn't even understtod that
USA-USA contacts were allowed. The official "objective" of the contest sa
Helpful advice, Tom. Thanks. I've always worried about using silcone grease
on connectors. I understand it helps seal the connector, but my fear is that
it could interfere with the electrical bond. On the face of it, getting
non-conducting grease on, e.g., the center terminal of an N-connector or
Many thanks to everybody who responded to my inquiry. I received over twenty
responses, with many excellent suggestions. Turns out most folks homebrew
their own connectors, using brass plumbing fittings, and I received a number
of innovative designs. The aluminum jacketed 1/2 inch 50 ohm hardline
(
My 160m vertical is 79ft high (wire running up a 26m Spiderbeam fiberglass
pole), with a capacity hat. Is it workable to put an 80m 1/4 wave wire on
the same mast join both antennas at the base, in the same way people make
multiband fan dipoles? The idea would be that when operationg on 80m, the
16
Hi All,
I'm looking for one or (preferably) two connectors for 50 ohm 1/2 inch
hardline - the CATV type, with a solid 1/8 in (approx) copper inner
conductor, solid aluminum tube for a shield and an outer vinyl jacket.
Again, this is the 50 ohm CATV hardline, not the more common 75 ohm type.
I'd pr
I have two bidirectional 720 ft beverages that use 450 ohm ladder line,
oriented NE-SW and NW-SE. The ladder line is supported by 4x4 wood posts,
about 7 ft above ground, spaced every 60 ft. The antenna works well, but has
turned out to be a maintenance nightmare. My first mistake was to anchor the
As Tom notes, the widest possible matching range for a T-Network is with two
adjustable capacitors (and, presumably, a variable inductor, typically a
roller inductor). Constraining any one of these parameters reduces the
available matching range. Further, Tom correctly observes that many hams
damag
My 26m Spiderbeam mast is made of a shiny black fiberglass material. Have
users of this or the shorter Spiderbeam masts had experience with how well
the masts hold up to UV radiation? My QTH is at 7000 ft elevation and the
sun shines 330 days/year, so UV degradation is a big problem. I've used
Kry
My forthcoming 160m vertical requires about a 700 ft run of coax. I'd like
to bury the coax over most of the run, but some of it will be elevated, with
high UV exposure. (I'm at 7000 ft elevation and sun shines 330 days/yr.) The
climate is very arid here (about 4-6 in rain/yr), so water ingress isn
Hi everyone,
I'm _finally_ trying to erect a decent vertical for 80m and 160m, and have
purchased a 26m (85ft) Spiderbeam mast. I'd really like to hear from guys
who have used this mast for these bands. I'll have about 60 120ft radials.
I've seen sheet from the manufacturer about using the mast as
Hi Jim,
I think we may talking at cross purposes! I certainly agree with your
explanation about how a choke is in the common mode circuit, but not the
differential circuit. In fact, that just what I said in my posting. I also
agree that in the common mode equivalent circuit, the coax feedline looks
ually worked quite well. Running 100W into a dummy load, with about 50 ft
of CAT5, showed no perceptable VSWR.
73,
Jim W8ZR
_
From: James Rodenkirch [mailto:rodenkirch_...@msn.com]
Sent: Monday, August 12, 2013 10:47 AM
To: Jim Garland; topband@contesting.com
Subject: RE: Topband:
I believe that if you parallel two twisted pairs of a CAT5 cable, you'll
have a 50 ohm transmission line.(Each twisted pair is 100 ohms). I've tried
this with CAT5e cable and find it works well, even for transmitting, up to
about 100W. The VSWR match was very close to 50 ohms. The problem is that
I'm interested in your comment about LMR400 and soldered braids, Tom. I
understand the point about shield current flowing on the insde of the foil
or braid closest to the center conductor, but if the shield connection is
faulty, oxidized, or has high resistance, then it seems to me the outer
braid
For spots, please go to your favorite
> ARC V6 or VE7CC DX cluster node.
>
> On 5/4/2013 11:13 PM, Jim Garland wrote:
> > I'm sure most of you know this already, but there are different
compression
> > F-connectors for ordinary RG6 and for quad-shield RG6. I use "Ideal"
I'm sure most of you know this already, but there are different compression
F-connectors for ordinary RG6 and for quad-shield RG6. I use "Ideal" brand
connectors with matching compression tool, and there is a color-coded band
for the two types of cables (blue for RG6 and black for quad-shield). It
46 matches
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