Sorry Jim K9YC but it is incorrect to say that a loading coil at the base
of an antenna, which is less than a quarter wave, will affect the high
current point of the antenna. Assuming the coil is pure L with no
distributed C, the current exiting the coil will be the same as that
entering it. It is
For many years after I was licensed in 1960, we were limited in G-land to
10 watts input to the PA (not output). So working DX was a major
achievement, although there were quite a few 'fat watts' around!
G3PU used to regularly work VK and ZL with a genuine 10 watts from his
cliff top QTH on the
Best top-band conditions I've heard in a while. Mid-West and West Coast
romping in both mornings, including CA - N6RO and WA6KHK.
73,
Tom G3OLB
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Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Steve,
For comparison my inverted-L is similar to yours with a 94 ft vertical
section and 43 ft horizontal (ish). It is on a tall tree, not a tower.
Like you, I use an L-network to match it and get a feed impedance on 1826.5
KHz of 50+j0. I have a 1600pF capacitor in parallel but no inductor as I
Good signals peaking at my sunrise this morning from Dennis ZL1AZ. Nice to
hear 160 conditions improving.
73,
Tom G3OLB
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Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Hello Greg,
Just to say thanks a million for the countless 160 metre QSOs we have had,
mainly at UK sunrise, over the past 15 years. Your remote station receiving
capability has always amazed me. I can imagine your frustration at hearing
and copying us so many times, when we were not hearing you.
Just to add to the discussion on band conditions, Mike W4EF near LA was
romping into UK this morning, Tuesday at 0800 sunrise, peaking 8 to 9 and
Larry N7DD was well over the 9. Apart from those two, the band was devoid
of CW during the short time I was on.
73,
Tom G3OLB
_
David G3WGN,
I'm sure you must have some tall trees down there in the Dart Valley! You
could save yourself a bundle in shipping charges alone by putting up a
simple wire inverted 'L' or a 'T'.
Use a pneumatic tennis ball launcher to place the halyard over the tree at
the highest point. I have
It's nice to hear the band back in good shape again after a few years. Big
CW signal from W4EF in CA this morning along with ZL3IX, also a string of
JAs/HL earlier this week.
Let's keep the 160 CW activity up!
73,
Tom G3OLB
_
Searchable Archives:
G4FTC wrote "The one thing that scares me with the tennis ball launcher is
the risk of the plastic air reservoir exploding..."
- which is why I always put on safety goggles when using mine.
73,
Tom G3OLB
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Searchable Archives: http://www.contesting.com/_topband - Topband
Outstanding sunrise conditions at 0800 today on top band. FM5BH on 1818 KHz
S9+. ZL3IX on 1826.5 long path peaking S8/9 on my meter.
RBN skimmers showing excellent path to USA but very little other activity.
Come on guys, turn that computer off and plug the key in!
73,
Tom G3OLB
I have to disagree with Steve VK6VZ and Dave W0FLS about conditions so far
this season on topband. Although talking about different paths and times,
regular daily long path skeds between myself with several other G's and
ZL3IX, have been remarkably successful and I have logged 23 completed QSOs
Fascinating presentation Steve, thank you.
Tom G3OLB
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Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
A couple of hours this morning on 160 CW yielded FR4NT, VE6WZ and ZL3IX as
well as some other old friends, so considering the high static levels,
conditions are pretty good!
73,
Tom G3OLB
_
Topband Reflector Archives - http://www.contesting.com/_topband
I used to use a slightly shortened 'L' with a small inductor at the base
until I was told by LA5HE that he could hear me on 80 as well as 160!
Using capacitor matching forms a low pass network which will reduce
harmonic radiation. The inductor method forms a high pass L-network.
BTW, why is it
Bob W7RH - you don't need expensive hard-to-find vacuum capacitors to
match a quarter wave 'L' or 'T' on top band. I use cheap multilayer high
voltage disc ceramics and these have been working perfectly at QRO levels
with my inverted 'L' for years.
I use 1600pF made up from 1000pF + 470pF + 220pf
Gary KA1J,
It struck me that maybe you originally cut your sloper a little longer so you
could match it with a simple capacitor.
My inverted L is resonant on its own, somewhere down in the 1.750 region. It’s
effectively matched to 50 ohms by an L network but the series inductance part
of the
Roger G3YRO – conditions haven’t been all bad on 160 lately. ZL3IX and I have
had 7 good long path QSOs in this month so far.
73,
Tom G3OLB
Sent from Mail for Windows 10
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Topband Reflector Archives - http://www.contesting.com/_topband
Sorry guys, I thought I posted the following about a month ago. Must be a long
delay echo on the 160 reflector!
Tom G3OLB
Just to say that I wholeheartedly endorse Roger's comments on repeat 160 metre
contacts. We are not all certificate hunters and many are only too happy to
rag-chew. In 58
Just to say that I wholeheartedly endorse Roger’s comments on repeat 160 metre
contacts. We are not all certificate hunters and many are only too happy to
rag-chew. In 58 years on top band, I have no idea of my DXCC score but it’s
quite a few. So please Mark K3MSB and all you others who are
Vic/David – looks like D10 field telephone cable may be readily available at:
http://armyradio.com/800-Meters-DON-10-WD1-TT-D-10-Twisted-Pair-Telephone-Cable.html
GBP 64.50 for 800 metres sound a pretty reasonable price to me.
73,
Tom G3OLB
_
Topband Reflector Archives -
Really good to hear 160 conditions getting better by the day! Greg ZL3IX was
peaking 569 running only 50 watts on long path at my sunrise today. Forget the
digital modes and start bashing that key!
73,
Tom G3OLB
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Topband Reflector Archives - http://www.contesting.com/_topband
Just to say I received my copy of Jeff's 'DXing on the edge' today,
complete with 19 chapters, bought from 'Book Depository' via Amazon. Price
including shipping was GBP 15.26. Now for some interesting reading!
73,
Tom G3OLB
_
Topband Reflector Archives -
Folks,
You don’t need expensive vacuum capacitors or bread slicers/toast racks to
match your 160 metre ‘L’. I use a low pass L-network consisting of 0.95
microhenrys in series and 1600 pF in parallel with the coax.
The inductor is not real and is made by slightly extending the length of the
Mike,
I just can’t figure out why you would use 807s in a remote tuner!
73,
Tom G3OLB
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Topband Reflector Archives - http://www.contesting.com/_topband
Frank,
Interesting that in the 1930s you folk in the colonies called the thing an
“aerial” and not an “antenna”!
73
Tom G3OLB
_
Topband Reflector Archives - http://www.contesting.com/_topband
Rather than use a filter capable of handling the transmit power, surely a
better solution for the K3 would be to use a separate 160m receiving antenna,
via a small filter on the BNC auxiliary antenna input.
73
Tom G3OLB
_
Topband Reflector Archives -
G4FKA: Once upon a time, all QSOs probably sounded like that!
What do you mean 'Once upon a time'? Have you listened on 160 lately?
Tom
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Topband Reflector Archives - http://www.contesting.com/_topband
..sorry, posted to wrong reflector!
_
Topband Reflector Archives - http://www.contesting.com/_topband
W8JI said: Collins got burned by this. They tried running a pure audio tone
into the
SSB transmitter of the early S line to generate CW.
.as did KW with their KW2000 over here.
Tom G3OLB
_
Topband Reflector Archives - http://www.contesting.com/_topband
Gary KA1J - take a look at this excellent article on ferriste baluns by GM3SEK:
http://www.ifwtech.co.uk/g3sek/in-prac/inpr1005_ext_v2.pdf
73
Tom G3OLB
_
Topband Reflector
The excellent web site for calculating matching network values should have
been:
http://home.sandiego.edu/~ekim/e194rfs01/jwmatcher/matcher2.html
not the one I posted yesterday.
73,
Tom G3OLB
_
Topband Reflector
Just to add a comment on this thread:
I do not use an inductor to match my inverted 'L', just a capacitor from coax
centre/bottom of wire to the radial point. Further I do not use big wide space
'toast-rack' Cs, but tiny ceramic ones rated at 6.3KV which will handle very
decent amounts of
- Original Message -
From: Tom Boucher
To: 160 reflector
Sent: Tuesday, July 23, 2013 6:30 PM
Subject: Inv-L joy
What bothers me about putting the actual antenna wire across the tree is that
it is then very close and in fact touching the tree. I'm not sure what loss the
tree would
It's the reference to termination resistors in the SPX data sheet that bothers
me.
Tom G3OLB
K1FZ wrote:
The antenna in a simpler single dipole configuration has the wire ends tied
with a perimeter wire to give very wide frequency banding. For a modern
version of the old T-top see.
Yes Tom, I was going to mention the polyprop guys as well. Worst stuff you
can use. Well remember a 60' mast bent across my neighbours roof as a result
of using polyprop guys which had degraded in UV. You get splinters of the
stuff in your hands as well!
I use polyester (Terylene, Dacron,
That's an interesting idea Red and worth a try.
73
Tom G3OLB
WO0W wrote: Perhaps you can take a portable transmitter and manual tuner to
the site. At the point where you wish to place an L network, attach the manual
tuner and transmitter and adjust the tuner for a good match. Take the tuner
Thinking again about this, we have missed out a stage. After measuring the
tuner output impedance, we need to make a temporary L network which, when
terminated with 50 ohms, looks like the antenna. Now put the MFJ on this
terminated network and measure it's R +/- jX values which will represent
A ham friend asked me to design a matching network for his 160 metre end fed
quarter wave, so I asked him to provide an impedance reading using his
MFJ-259B. I would then use the Berkley site
(http://bwrc.eecs.berkeley.edu/Research/RF/projects/60GHz/matching/ImpMatch.html
) to provide the
Herb,
On the recommendation of John G3PQA, I recently changed my router from a D-Link
unit to an ADDON NWAR-3670 which appears to have much better RFI immunity. I'm
not getting any dropouts at all now and I do not have an OZ1CTK type filter in
line, just some ferrite rings of unknown origin on
G3OIT wrote:
We don't have animals here that eat antennas
Well something just ate my control cable to my remote antenna switch box! Pesky
rabbits I think.
73
Tom G3OLB
___
UR RST IS ... ... ..9 QSB QSB - hw? BK
Nice to work some old friends last night although G activity seemed low and the
last couple of hours were a little painful. 160 QSOs with at least one dupe
which was my logging error (sorry Terry!) Nice quiet channel for almost all of
the contest and noticeably few keying clicks on the band -
Tree - delete this please - sent it to the wrong reflector!
73, Tom G3OLB
- Original Message -
From: Tom Boucher
To: 160 reflector
Sent: Sunday, February 12, 2012 10:17 AM
Subject: RSGB 1st 1.8 MHz Contest
Nice to work some old friends last night although G activity seemed low
Just a few comments to Mark WD4ELG:
I too have a single short Beverage, about 350' over clay soil and sloping up a
hill to the west, fed with about a quarter mile of RG58. It's really too short
for top-band, but it does work. Myself and some other Gs have been carrying out
daily long path
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