Joe and others, Thanks for your helpful information. So, this will not be a
difficult project at all. I have a pretty decent start on my radial system -
only need to put down 10 more or so. I am kind of fired up about getting back
on 160. It’s been a long time (40 years) since I was on the band
> On 2018-09-04 1:18 PM, Richard Beerman wrote:
Rick and Bob, Thanks for such swift replies. Looks like I should try
to reinforce the 3/8” tubing (it’s pretty short) with a wood dowel or
perhaps with smaller or larger aluminum tubing.
Unless you want to redesign the antenna's taper schedule, I
Beerman
Sent: 04 September 2018 17:18
To: Joe Subich, W4TV
Cc: topband@contesting.com
Subject: Re: Topband: Air wound coil
Rick and Bob, Thanks for such swift replies. Looks like I should try to
reinforce the 3/8” tubing (it’s pretty short) with a wood dowel or perhaps with
smaller or larger
Rick and Bob, Thanks for such swift replies. Looks like I should try to
reinforce the 3/8” tubing (it’s pretty short) with a wood dowel or perhaps with
smaller or larger aluminum tubing. Then the fishing line method should be a
perfect solution using 24 or 26 gauge wire. Using this method, I t
On 9/4/2018 9:36 AM, Richard Beerman wrote:
Anyway, here is my question…. my vertical has 3/8” tubing at the top. Pretty flimsy to connect top loading wires except maybe small gauge wire. I am not sure how well small gauge wire will handle voltages that may appear at the top of a 68’ vertical. So
Top Banders, This discussion has been tremendously helpful to me as I also am
going to put a DX Engineering 68’ vertical when the QRN subsides here in South
Texas. Initially, I planned to install a large inductor (looks like it came
from a BC transmitter) that I found at a local hamfest. My ca
Getting to six would result in a smaller top hat but may not be worth
the mechanical hassle.
If the mast has traditional three way guying, the mechanical hassle for
a six wire top hat may not be that much greater than a four wire top
hat.
If the top hat wires slope downward, keeping them to t
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 -- versu
-Original Message-
From: Eugene Colton
Sent: Monday, September 03, 2018 12:25 PM
To: donov...@starpower.net
Cc: topband@contesting.com ; MU 4CX250B
Subject: Re: Topband: Air wound coil
Jim,
@ say, 1.83 MHz, the electrical length of your vertical is about 47.4 deg,
necessitating a top
Grant wrote:
>>> Or the inverse as I did, cut my T for the low end of the band. Then three
>>> series capacitors with PCB relays to short each individually (none, 1, 2,
>>> or 3) yielded nearly full band coverage <1.5:1 swr. My T is 85' to top and
>>> a 50:25 ohm TLT is a close match, then the
se insulator. Much better to use top loading to avoid high
> voltage at the base.
>
>
> 73
> Frank
> W3LPL
>
> - Original Message -
>
> From: "Jim Garland" <4cx2...@miamioh.edu>
> To: topband@contesting.com
> Sent: Sunday, September 2, 2018
rland" <4cx2...@miamioh.edu>
To: topband@contesting.com
Sent: Sunday, September 2, 2018 10:03:32 PM
Subject: Re: Topband: Air wound coil
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
abou
Jim,
I have that 80m quarter wave vertical by DXE and use a simple matching network
with it for 160m. As it stands, the vertical is basically an 1/8 monopole with
~12 ohms real Z on 160, so I use a 4:1 balun to bring the 50 ohm coax down to
12 ohms then add a 4 inch diameter coil in series to
opband@contesting.com
Subject: Re: Topband: Air wound coil
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
I have often used an Omega match, in this situation.
Have a great day,
--... ...-- Dale - WC7S in Wy
"Actions speak louder than words"
1856 - Abraham Lincoln
_
Topband Reflector Archives - http://www.contesting.com/_topband
Jim,
Maybe a combo of the two methods, that way you can tap up from the bottom of
the loading inductor a few turns to get a perfect match for the coax
feedline. Plus have the convenience of adjusting to resonance by tapping
down from the top of the same coil.
73,Roy K6XK
On this
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
73 Clive
GM3POI
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom
Boucher
Sent: 02 September 2018 18:20
To: 160 reflector
Subject: Topband: Air wound coil
Bob W7RH - you don't need expensive hard-to-find vacuum capacitors to match
a quarter wave &#
a DC short to ground for the antenna. No Caps needed. 73 Clive
GM3POI
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom
Boucher
Sent: 02 September 2018 18:20
To: 160 reflector
Subject: Topband: Air wound coil
Bob W7RH - you don't need expe
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
Per the following added comments.
Me too.
Or the inverse as I did, cut my T for the low end of the band. Then
three series capacitors with PCB relays to short each individually
(none, 1, 2, or 3) yielded nearly full band coverage <1.5:1 swr. My T
is 85' to top and a 50:25 ohm TLT is a close
It may very well be true that tank coils made from round copper have some
slight advantages over edge-wound. But after all is said and done, does
this really make a great deal of difference? :-)
I have an edge-wound roller inductor in my homebrew amplifier.
http://www.w0btu.com/833C_linear_amplifie
On 9/1/2018 3:42 PM, Grant Saviers wrote:
Me too.
Or the inverse as I did, cut my T for the low end of the band. Then
three series capacitors with PCB relays to short each individually
(none, 1, 2, or 3) yielded nearly full band coverage <1.5:1 swr. My T
is 85' to top and a 50:25 ohm TLT is
Me too.
Or the inverse as I did, cut my T for the low end of the band. Then
three series capacitors with PCB relays to short each individually
(none, 1, 2, or 3) yielded nearly full band coverage <1.5:1 swr. My T
is 85' to top and a 50:25 ohm TLT is a close match, then the capacitor
stack fo
Guys, I'm confounded by the complexity suggested for all band coverage
of 160m "Top Loaded T Antenna".
May I make a simple suggestion. A simple T antenna will have a radiation
resistance of 10-12 Ohms with electrical height of say 43ft with a Good
ground system of quarter wave radials. By trim
Hi Rick, Wes,
I said it was a "killer piece of copper". I did not compare it to anything.
Mostly I like the way that edge-wound coil looks (what was on my mind when
I said "killer") The same way I like a lit up and glowing red 3-1000Z
putting out 1500 watts, or the spooky glow of 866A's and 872A'
-Original Message-
From: Richard (Rick) Karlquist
Sent: Friday, August 31, 2018 7:13 AM
To: Jim Thomson ; Guy Olinger K2AV
Cc: TopBand List
Subject: Re: Topband: Air Wound Coil
## What are you using to measure Q ?? I did discover one anomoly with
coils
and Q. XL increases
Besides the advantage in roller inductors, edge wound more easily accommodates
adjustable taps, using slide-on clips. It also makes the coil more
mechanically stiff, for a given number of turns per inch than does round wire.
That's probably the reason that edge-wound stock is more often used
On 8/31/2018 6:09 AM, Jim Thomson wrote:
## Are you sure about this ? I have used .25 edge wound rollers,
I am sure that flat conductors result in lower Q than round conductor.
I have done innumerable Q meter measurements to confirm this.
I didn't say that flat conductors don't work at
-Original Message-
From: Richard (Rick) Karlquist
Sent: Thursday, August 30, 2018 5:44 PM
To: Guy Olinger K2AV ; Jim Thomson
Cc: TopBand List
Subject: Re: Topband: Air Wound Coil
On 8/30/2018 3:44 PM, Guy Olinger K2AV wrote:
You can also get the edge-wound (flat) 1/4 inch by 1/16
: Topband: Air Wound Coil
Thanks again for all the replies Guys, I am running so late on getting ready
for this season I am just looking for a quick and easy way out,
I'll get the vertical up and see what I need, I might be over complicating
things as usual,
Thanks
Trevor
EI2GLB
- Original Me
: "MR TREVOR DUNNE"
Cc: "topband List"
Sent: Thursday, 30 August, 2018 21:03:09
Subject: Re: Topband: Air Wound Coil
Thanks for the replies I want to be able to tap it at various points to allow
for some movement up the band, I don't actually know how much inductance a
ock don't fancy waiting a few months more it's
> been 4 already,
>
> Thanks
> Trevor
> EI2GLB
> - Original Message -
> From: MR TREVOR DUNNE
> To: ''''''topband List'
> Sent: Thu, 30 Aug 2018 07:44:04 +0100 (IST)
> Su
I agree with Rick. The advantage to the edge-wound inductor is the better heat
dissipation; needed because the Q is lower :-)
Wes N7WS
On 8/30/2018 5:44 PM, Richard (Rick) Karlquist wrote:
On 8/30/2018 3:44 PM, Guy Olinger K2AV wrote:
You can also get the edge-wound (flat) 1/4 inch by 1/
I wind my air wound coils using 4 mm copper tubing on a form such as a baked
bean can. It holds its shape when the form is removed and I then stretch out
the coil longitudinally to achieve the pitch required. Inductance can be
easily calculated.
The copper tubing is very easy to solder and tap
On 8/30/2018 3:44 PM, Guy Olinger K2AV wrote:
You can also get the edge-wound (flat) 1/4 inch by 1/16 inch coil that they
use in the ATR-30 rotary coil tuner. That's a killer piece of copper.
Actually no. Edge wound is inferior in terms of Q to round wire.
It only makes sense for a rotary
o from across the pond to speed it up.
On Thu, Aug 30, 2018 at 5:55 PM Jim Thomson wrote:
> Date: Thu, 30 Aug 2018 07:44:04 +0100 (IST)
> From: MR TREVOR DUNNE
> To: ''''''topband List'
> Subject: Topband: Air Wound Coil
>
>
> I'm
Date: Thu, 30 Aug 2018 07:44:04 +0100 (IST)
From: MR TREVOR DUNNE
To: ''''''topband List'
Subject: Topband: Air Wound Coil
http://www.mfjenterprises.com/Product.php?productid=404-0669
I've had one on order from MFJ via a UK company for 4 months now
al Message -
From: MR TREVOR DUNNE
To: ''''''topband List'
Sent: Thu, 30 Aug 2018 07:44:04 +0100 (IST)
Subject: Topband: Air Wound Coil
Hi All
I'm looking for an Air wondering coil like in this link,
http://www.mfjenterprises.com/Product.php?producti
>You can see a picture of the coil I wound for my 160M antenna match
here, along with some other more complicated link coupled tuners:
http://n3qe.org/tuners.html
Actual homebrew! Just like the good ole' days. Beautiful!
VE7XF
_
Topband Reflector Archives - http://www.contest
ct: Re: Topband: Air Wound Coil
To follow up on what Tim said, I often just use PVC pipe for my coil forms
and wind my coils using enamel coated wire (16 or 14 gauge enamel coated
wire), and to keep things simple I often just use close wound turns (no
space between turns). With no space between turn
If you don't have plastic pipe, select a plastic beaker from the kitchen
cupboard.
David G3UNA-G6CP
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Don Kirk
Sent: 30 August 2018 12:53
To: Tim Shoppa
Cc: Trevor; topband
Subject: Re: Topband: Air
To follow up on what Tim said, I often just use PVC pipe for my coil forms
and wind my coils using enamel coated wire (16 or 14 gauge enamel coated
wire), and to keep things simple I often just use close wound turns (no
space between turns). With no space between turns the coil loss will not
be mi
That is a very nice transmitter tank coil for a kilowatt amplifier. But if you
have already calculated or measured the inductance you need, you can just wrap
reasonable gauge insulated wire around any cardboard or plastic form you find.
I used magnet wire around a cardboard tube. You can see a p
Hi Trevor,
I ordered one of those coils from MFJ (Part # 404-0669) on July 6th and it
was on back order at that time, and it shipped from MFJ to me on August 1st
(when you order one and they are on back order I think it normally takes
them less than 1 month to produce new ones based on my experie
Hi All
I'm looking for an Air wondering coil like in this link,
http://www.mfjenterprises.com/Product.php?productid=404-0669
I've had one on order from MFJ via a UK company for 4 months now and no sign of
it, I want to build a at matching network for my 160m inverted T using it or
something si
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