loopantennas@groups.io

Re: Message from Andy Ikin - I don't have to cut into my ALA-1...

Rob Moore

Hi Nigel,

At least, as I said before I don't have to "operate" on the Aluminum.
 I'm glad I held off for a few days thinking about it.  Mea culpa!

Andy's a good guy and I understand why he doesn't want to talk much
about the amp, provide circuit diagrams, etc.  He's spent a number of
years working on it and perfecting his antennas and according to the
reviews, has done a great job on it.  The antennas are his livelihood
so why should he give out his secrets?

Actually, I'd be really interested to hear something about his
background.  Did he work for a Radio company or has this always been a
hobby?  When did he get the idea to make a better loop antenna?  What
new things will be coming from his shop in the future?  Would he be
willing to "Educate" some of us here on antenna design?  It would be
fascinating.

Transformers can be calculated based on the core material, frequency
response, and impedance desired and then measured and tried to tweak
them up.  Go for it!

Rob


--- In loopantennas@..., gandalfg8@... wrote:

Hi Rob

Being the totally wonderful and noble sort of chap that I  am, Ishall resist
even the slightest temptation to say.....
"told yer so" :-)

Joking apart, whilst the content of Andy's emails don't surprise me, that
you got them at all could be considered surprising given his earlier comments.

Although I'm not daft enough to suppose he'll want to supply us with all the
circuit information, well...I probably am daft enough but don'tsuppose  he
is:-), it is gratifying to think we might not be perceived as quitesuch a
threat or adversaries after all.

As I said before, it's quite intriguing how much conjecture thisgroup,  
myself included, has entered into regarding the make up of theWellbrook
antennas, and yet none of us has actually gone so far as breakingapart our own
working 1530s etc.

Given that it wouldn't be all that difficult, I think that's a fair
indication that those of us who've got them appreciate them enoughthat we just
prefer to use them.

Having said that, how many turns did you say was on thattransformer?:-)

regards

Nigel
GM8PZR








[Non-text portions of this message have been removed]

Message from Andy Ikin - I don't have to cut into my ALA-1530.

Rob Moore

#3512

Here is a synopsis of messages I recently received from Andy Ikin,
they're pretty interesting and put to rest several questions that
people have about the ALA-1530.  I stand corrected on the loop
configuration - The aluminum is the actual loop.

Rob

---------------------------------------------

Dear Rob,

Further to your questions ref the above.

The loop is a single turn "un-shielded" coupled to a centre tapped
grounded phase reversal transformer at the input of a balanced
amplifier. The phase reversal transformer forces the two halves of the
loop to be at 180 degree phase difference. Hence the "Vertical"
E-field will cancel out and only the H field will induce a current
into the loop.  The H-field will not induce any current into the loop,
when the plane of the loop is facing the lines of magnetic flux. Hence
the figure of 8 pattern.

Btw, during the development phase of the loop design many years ago,
several shielded versions were made; I was unable to measure any
difference rejection of local E-Field radiation. In fact the shield
reduced the HF sensitivity.

The ALA100 works in the same way. However, because the ALA100 has a
much larger aperture, then less amplifier gain is needed, hence a
lower amplifier noise floor.

Kind regards

Andy

Re: Message from Andy Ikin - I don't have to cut into my ALA-1...

[email protected]

#3513

In a message dated 22/05/2007 22:25:20 GMT Daylight Time,  
rmoore5@... writes:

 
 
 
Here is a synopsis of messages I recently received from Andy  Ikin,
they're pretty interesting and put to rest several questions  that
people have about the ALA-1530. I stand corrected on the  loop
configuration - The aluminum is the actual  loop.






--------------------------------
Hi Rob
 
Being the totally wonderful and noble sort of chap that I  am, I shall resist 
even the slightest temptation to say.....
"told yer so" :-)
 
Joking apart, whilst the content of Andy's emails don't surprise me,  that 
you got them at all could be considered surprising given his earlier  comments.
 
Although I'm not daft enough to suppose he'll want to supply us with  all the 
circuit information, well...I probably am daft enough but don't suppose  he 
is:-), it is gratifying to think we might not be perceived as quite such a  
threat or adversaries after all.
 
As I said before, it's quite intriguing how much conjecture this group,  
myself included, has entered into regarding the make up of the  Wellbrook 
antennas, and yet none of us has actually gone so far as breaking  apart our own 
working 1530s etc.
 
Given that it wouldn't be all that difficult, I think that's a fair  
indication that those of us who've got them appreciate them enough that we just  
prefer to use them.
 
Having said that, how many turns did you say was on that  transformer?:-)
 
regards
 
Nigel
GM8PZR

Re: Building my first loop

#3511

At 3:19 pm ((PDT)) Mon May 21, 2007, Len Warner wrote:
[snip]
 ... high range ... two sections in series ... Since the
minimum variable capacitance will be halved but not all
the strays will be, this will not be a 2f frequency range
but will be a 0 - C/2 top range [snip]Oops: wouldn't be a 2f range anyway, forgot the sqrt.

Should read "... this will not be a 1.4f frequency range
but will be a 0 - C/2 top range with considerable overlap
with the 0 - C single-section range ...".

Re: Building my first loop

#3510

At 14:26 07/05/21, Digest Number 822 wrote:
    Posted by: "gandalfg8@..." gandalfg8@... bibliophileuk
    Date: Sun May 20, 2007 11:39 am ((PDT))
[snip]
If you want to increase capacitance you need to wire them in  parallel.
[snip] a reasonable general solution for experimantation might be to wire
one  section across the loop and then wire a switch so as to add the other
sections in parallel one at a time.
This will give you full range swings of 0 to 280, 0 to 560, 0 to 840, and 0
to 1120, which is quite a range.But with a lot of not very useful overlap.

A better way, with one less switch, would be to
 - wire the first section across the loop,
 - parallel the second section with 280pF and
   connect via a switch to the first section, and
 - parallel the 3d and 4th sections and 840pF
   and connect via a 2nd switch.

If you can find a 3-position progressive shorting
switch, so much the better.

This scheme will give you 3 non-overlapping ranges,
0 - C, C - 3C, and 3C - 7C, though in practice you
might choose to use slightly smaller fixed capacitors
so there is just a little overlap between ranges.

The reason for adding sections 3 and 4 as one range
is that otherwise the tuning rate would be very slow
on the lowest frequency range, because of the large
fixed capacitor and the fact that the tuning ratio is
the square root of the capacitor ratio.

[You can get another high range by switching two
sections in series to halve the values. Since the
minimum variable capacitance will be halved but not all
the strays will be, this will not be a 2f frequency range
but will be a 0 - C/2 top range with considerable overlap
with the 0 - C single-section range - unless you choose
to pad that with 140pF to become a C/2 - C range.]

 Note that the "0" in each case is theoretical only, in practice there will
always be some residual capacitance at the minimum setting,The minimum capacitance could be 20pF or more.
If you want to find out accurately and you have a frequency
counter or accurate receiver scale, it can be done by making
an oscillator using a fixed inductor and comparing the
variable against some small fixed capacitors.

Even if you don't have one which exactly matches the
minimum capacitance, you can get a calibration which
will allow you to calculate the minimum capacitance
from the maximum frequency.

that will again increase as more sections are added in parallel.This no longer matters if the ranges are extended with fixed
capacitors, as the minimum capacitance and strays can be
incorporated into the value of the fixed capacitor. Only the
maximum frequency on the highest range is limited by the
minimum variable capacitance plus strays.


Regards, LenW

Re: Building my first loop

#3508

At 14:26 07/05/21, Digest Number 822 wrote:
    Posted by: "noswadplease" ewdawso_1@... noswadplease
    Date: Sun May 20, 2007 8:38 am ((PDT))

I am in the parts gathering stage to building my first loop.  I have
picked up a 4 section tuning capacitor 280 uuf per section.  I am not
sure if I should connect each section in seriesSince the rotors are very likely on a common metal shaft,
probably you cannot connect more than 2 sections in series.

and connect the antenna to the first ant last section
or is there a better way to wire this.Much depends on how big your loop is and what frequencies
you want to tune, which you haven't cared to tell us :-(

Re: building my first loop

[email protected]

#3509

In a message dated 21/05/2007 16:01:10 GMT Daylight Time,  
ewdawso_1@... writes:

Thanks  Nigel and Jim, you both clarified for me what I need to do. I am 
just a  novice and am learning as I go. Ed Dawson

----------------------------------
Hi Ed
 
Glad to be of help.
 
Have fun, always the most important bit:-), and let us know how it  goes.
 
regards
 
Nigel
GM8PZR

Re: building my first loop

#3507

Thanks Nigel and Jim, you both clarified for me what I need to do. I am
just a novice and am learning as I go.   Ed Dawson

Re: Interesting Loop Antenna On Ebay

Richard Zolla

#3506

Michael,

Its a collectors item, and if you had a radio as old as the antenna
you might fine it a great part of your collection.

Rick





--- In loopantennas@..., "Michael Stevenson"
<portstevos@...> wrote:

Ah!! Now I see how much it is going for, $99.00 but no bids yetwith only 17 hours to go! Does this mean that the antenna would not
be worth the $99.00 or does it mean that it would not be much of a
performing antenna compared to the latest designs??

Best wishes!

Michael S
  ----- Original Message -----
  From: van lincoln
  To: loopantennas@...
  Sent: Monday, May 21, 2007 1:43 AM
  Subject: Re: [loopantennas] Re: Interesting Loop Antenna On Ebay


  here's the link:

  

  van lincoln wd8aam

  At 09:01 AM 5/20/2007 -0000, you wrote:
  >--- In loopantennas@..., "portstevos" <portstevos@>wrote:
  >>
  >> --- In loopantennas@..., "Richard Zolla" <N8NKN@>wrote:
  >> >
  >> > Loops have been around for quite a while.
  >> > Check out the "Bodine Loop" on Ebay.
  >> >
  >> > N6NKN
  >> >
  >> I had a search on ebay but could not find it, can you pleasegive me
  >> some further details or send me the link?
  >>
  >> Thanks and best wishes from Australia!
  >>
  >> Michael S
  >>
  >
  >
  >I couldn't find it on ebay either. But Google yielded thischarming item:
  >
  >(Bottom left, c. 1926)
  >
  >Regards, Paul Norman (Left Coast)
  >
  >
  >
  >If you've got links, post them in the Links section!
  >
  >
  >Post files here. If the file comes from a website, please put itin the
  Links rather than uploading the file.
  >
  >
  >You can now view images at higher resolution in Photos. UploadJPG and GIF
  into Photos. Please convert BMP or TIF to JPG or GIF beforeuploading.
  >
  >
  >And please trim all this when replying!
  >Yahoo! Groups Links
  >
  >
  >
  >




[Non-text portions of this message have been removed]

Re: Interesting Loop Antenna On Ebay

Michael Stevenson

#3505

Ah!! Now I see how much it is going for, $99.00 but no bids yet with only 17 hours to go! Does this mean that the antenna would not be worth the $99.00 or does it mean that it would not be much of a performing antenna compared to the latest designs??

Best wishes!

Michael S

Show quoted text

----- Original Message ----- 
  From: van lincoln 
  To: loopantennas@... 
  Sent: Monday, May 21, 2007 1:43 AM
  Subject: Re: [loopantennas] Re: Interesting Loop Antenna On Ebay


  here's the link:

  

  van lincoln wd8aam

  At 09:01 AM 5/20/2007 -0000, you wrote:
  >--- In loopantennas@..., "portstevos" <portstevos@...> wrote:
  >>
  >> --- In loopantennas@..., "Richard Zolla" <N8NKN@> wrote:
  >> >
  >> > Loops have been around for quite a while.
  >> > Check out the "Bodine Loop" on Ebay.
  >> > 
  >> > N6NKN
  >> >
  >> I had a search on ebay but could not find it, can you please give me
  >> some further details or send me the link?
  >> 
  >> Thanks and best wishes from Australia!
  >> 
  >> Michael S
  >>
  >
  >
  >I couldn't find it on ebay either. But Google yielded this charming item:
  >
  >(Bottom left, c. 1926)
  >
  >Regards, Paul Norman (Left Coast)
  >
  >
  >
  >If you've got links, post them in the Links section!
  >
  >
  >Post files here. If the file comes from a website, please put it in the
  Links rather than uploading the file.
  >
  >
  >You can now view images at higher resolution in Photos. Upload JPG and GIF
  into Photos. Please convert BMP or TIF to JPG or GIF before uploading.
  >
  >
  >And please trim all this when replying! 
  >Yahoo! Groups Links
  >
  >
  >
  >

Re: Interesting Loop Antenna On Ebay

Michael Stevenson

#3504

Ah yes, it is a huge oblong loop for medium wave, I wonder how it worked compared to the more conventional looking Lincoln loop beside it?

I was going to build an active medium wave loop antenna back in the early 1990s, I had all the materials ready to go and then we moved house, I lost the construction details and diagrams and some of the parts and for the life of me, I could not locate them or even come across the same article again, it was in Practical Wireless from the mid 1980s, I have searched everywhere through Practical Wireless archives but no luck!

Never mind! What cost was the Bodine loop going for?

Best wishes!

Michael S

Show quoted text

----- Original Message ----- 
  From: Paul Norman 
  To: loopantennas@... 
  Sent: Sunday, May 20, 2007 7:01 PM
  Subject: [loopantennas] Re: Interesting Loop Antenna On Ebay


  --- In loopantennas@..., "portstevos" <portstevos@...> wrote:
  >
  > --- In loopantennas@..., "Richard Zolla" <N8NKN@> wrote:
  > >
  > > Loops have been around for quite a while.
  > > Check out the "Bodine Loop" on Ebay.
  > > 
  > > N6NKN
  > >
  > I had a search on ebay but could not find it, can you please give me
  > some further details or send me the link?
  > 
  > Thanks and best wishes from Australia!
  > 
  > Michael S
  >

  I couldn't find it on ebay either. But Google yielded this charming item:
  
  (Bottom left, c. 1926)

  Regards, Paul Norman (Left Coast)

Re: Building my first loop

Jim Dunstan

#3503

At 02:49 PM 5/20/2007 +0000, you wrote:

I am in the parts gathering stage to building my first loop. I have
picked up a 4 section tuning capacitor 280 uuf per section. I am not
sure if I should connect each section in series and connect the antenna
to the first ant last section or is there a better way to wire this.
Thanks Ed Dawson
Hi Ed,

You did not say what frequencies you are building the new loop.  I am assuming the loop is for the MW frequencies ... eg 540-1700Khz.

In any event it sounds as if you don't quite understand how such a capacitor can be connected in series or parallel.  So here goes:

Your capacitor will have 4 sections .... each section will have 1 or 2 connectors for each of the sections.  Each of the connectors will represent 1 capacitor between it and the frame.  In other words each capacitor section will be 280 uufd maximum between one tab and the frame.

Each tab will represent 280 uuf between it and the frame.  If you connect 2 tabs in parallel then it will represent 560 uufd to the frame.  If you connect 3 tabs in parallel you will have 840 uufd between them and the frame.  If you connect all of them in parallel you will have 1120 uufd maximum to the frame.

Now it is possible to connect the in series .... to do so you will have to isolate the frame.  Connect 2 tabs in parallel and the other 2 tabs in parallel and the maximum capacity between these pairs will be 280 uufd.

If your loop is designed for MW then a series connection will result in too little capacitance,  you generally need a capacitor that will give you a maximum of 350 to 500 uufd.

Jim

Re: Interesting Loop Antenna On Ebay

#3502

Some of the old Zenith floor model tube radios from the 40's used a loop antenna called the Wave Magnet.It was wound on a cardboard form.

Show quoted text

----- Original Message ----- 
  From: van lincoln 
  To: loopantennas@... 
  Sent: Sunday, May 20, 2007 10:43 AM
  Subject: Re: [loopantennas] Re: Interesting Loop Antenna On Ebay


  here's the link:

  

  van lincoln wd8aam

  At 09:01 AM 5/20/2007 -0000, you wrote:
  >--- In loopantennas@..., "portstevos" <portstevos@...> wrote:
  >>
  >> --- In loopantennas@..., "Richard Zolla" <N8NKN@> wrote:
  >> >
  >> > Loops have been around for quite a while.
  >> > Check out the "Bodine Loop" on Ebay.
  >> > 
  >> > N6NKN
  >> >
  >> I had a search on ebay but could not find it, can you please give me
  >> some further details or send me the link?
  >> 
  >> Thanks and best wishes from Australia!
  >> 
  >> Michael S
  >>
  >
  >
  >I couldn't find it on ebay either. But Google yielded this charming item:
  >
  >(Bottom left, c. 1926)
  >
  >Regards, Paul Norman (Left Coast)
  >
  >
  >
  >If you've got links, post them in the Links section!
  >
  >
  >Post files here. If the file comes from a website, please put it in the
  Links rather than uploading the file.
  >
  >
  >You can now view images at higher resolution in Photos. Upload JPG and GIF
  into Photos. Please convert BMP or TIF to JPG or GIF before uploading.
  >
  >
  >And please trim all this when replying! 
  >Yahoo! Groups Links
  >
  >
  >
  >

Re: Interesting Loop Antenna On Ebay

#3500

looks well engineered even for today

Paul V Birke PEng
Guelph ON Canada

Show quoted text

----- Original Message ----
From: van lincoln <vlincoln@...>
To: loopantennas@...
Sent: Sunday, May 20, 2007 11:43:55 AM
Subject: Re: [loopantennas] Re: Interesting Loop Antenna On Ebay









  


    
            here's the link:



. com/2r57qp



van lincoln wd8aam



At 09:01 AM 5/20/2007 -0000, you wrote:

--- In loopantennas@ yahoogroups. com, "portstevos" <portstevos@ ...> wrote:--- In loopantennas@ yahoogroups. com, "Richard Zolla" <N8NKN@> wrote:Loops have been around for quite a while.Check out the "Bodine Loop" on Ebay.N6NKNI had a search on ebay but could not find it, can you please give mesome further details or send me the link?Thanks and best wishes from Australia!Michael SI couldn't find it on ebay either. But Google yielded this charming item: eum.com/MISCACCY .HTM(Bottom left, c. 1926)Regards, Paul Norman (Left Coast)If you've got links, post them in the Links section!. yahoo.com/ group/loopantenn as/linksPost files here. If the file comes from a website, please put it in theLinks rather than uploading the file.

. yahoo.com/ group/loopantenn as/filesYou can now view images at higher resolution in Photos. Upload JPG and GIFinto Photos. Please convert BMP or TIF to JPG or GIF before uploading.

. yahoo.com/ group/loopantenn as/photosAnd please trim all this when replying! Yahoo! Groups Links

    
  

    
    




<!--

#ygrp-mlmsg {font-size:13px;font-family:arial, helvetica, clean, sans-serif;}
#ygrp-mlmsg table {font-size:inherit;font:100%;}
#ygrp-mlmsg select, input, textarea {font:99% arial, helvetica, clean, sans-serif;}
#ygrp-mlmsg pre, code {font:115% monospace;}
#ygrp-mlmsg * {line-height:1.22em;}
#ygrp-text{
font-family:Georgia;
}
#ygrp-text p{
margin:0 0 1em 0;}
#ygrp-tpmsgs{
font-family:Arial;
clear:both;}
#ygrp-vitnav{
padding-top:10px;font-family:Verdana;font-size:77%;margin:0;}
#ygrp-vitnav a{
padding:0 1px;}
#ygrp-actbar{
clear:both;margin:25px 0;white-space:nowrap;color:#666;text-align:right;}
#ygrp-actbar .left{
float:left;white-space:nowrap;}
.bld{font-weight:bold;}
#ygrp-grft{
font-family:Verdana;font-size:77%;padding:15px 0;}
#ygrp-ft{
font-family:verdana;font-size:77%;border-top:1px solid #666;
padding:5px 0;
}
#ygrp-mlmsg #logo{
padding-bottom:10px;}

#ygrp-vital{
background-color:#e0ecee;margin-bottom:20px;padding:2px 0 8px 8px;}
#ygrp-vital #vithd{
font-size:77%;font-family:Verdana;font-weight:bold;color:#333;text-transform:uppercase;}
#ygrp-vital ul{
padding:0;margin:2px 0;}
#ygrp-vital ul li{
list-style-type:none;clear:both;border:1px solid #e0ecee;
}
#ygrp-vital ul li .ct{
font-weight:bold;color:#ff7900;float:right;width:2em;text-align:right;padding-right:.5em;}
#ygrp-vital ul li .cat{
font-weight:bold;}
#ygrp-vital a {
text-decoration:none;}

#ygrp-vital a:hover{
text-decoration:underline;}

#ygrp-sponsor #hd{
color:#999;font-size:77%;}
#ygrp-sponsor #ov{
padding:6px 13px;background-color:#e0ecee;margin-bottom:20px;}
#ygrp-sponsor #ov ul{
padding:0 0 0 8px;margin:0;}
#ygrp-sponsor #ov li{
list-style-type:square;padding:6px 0;font-size:77%;}
#ygrp-sponsor #ov li a{
text-decoration:none;font-size:130%;}
#ygrp-sponsor #nc {
background-color:#eee;margin-bottom:20px;padding:0 8px;}
#ygrp-sponsor .ad{
padding:8px 0;}
#ygrp-sponsor .ad #hd1{
font-family:Arial;font-weight:bold;color:#628c2a;font-size:100%;line-height:122%;}
#ygrp-sponsor .ad a{
text-decoration:none;}
#ygrp-sponsor .ad a:hover{
text-decoration:underline;}
#ygrp-sponsor .ad p{
margin:0;}
o {font-size:0;}
.MsoNormal {
margin:0 0 0 0;}
#ygrp-text tt{
font-size:120%;}
blockquote{margin:0 0 0 4px;}
.replbq {margin:4;}
-->

Re: Interesting Loop Antenna On Ebay

#3499

That's how I found it in an instant awhile ago as well.

Don
Upland, CA

Richard Zolla wrote:

Show quoted text

Strange, I just type in "Bodine loop" in the search and there it is!!!

--- In loopantennas@..., van lincoln <vlincoln@...> wrote:
  
here's the link:

van lincoln wd8aam

At 09:01 AM 5/20/2007 -0000, you wrote:
    
--- In loopantennas@..., "portstevos" <portstevos@> wrote:
  
--- In loopantennas@..., "Richard Zolla" <N8NKN@> wrote:
  
Loops have been around for quite a while.
Check out the "Bodine Loop" on Ebay.

N6NKN

          I had a search on ebay but could not find it, can you please give me
  
some further details or send me the link?

Thanks and best wishes from Australia!

Michael S

        I couldn't find it on ebay either. But Google yielded this charming item:
  
(Bottom left, c. 1926)

Regards, Paul Norman (Left Coast)

If you've got links, post them in the Links section!

Post files here. If the file comes from a website, please put it in the
  
Links rather than uploading the file.
    
You can now view images at higher resolution in Photos. Upload JPG and GIF
  
into Photos. Please convert BMP or TIF to JPG or GIF before uploading.
  
And please trim all this when replying! Yahoo! Groups Links

If you've got links, post them in the Links section!

Post files here. If the file comes from a website, please put it in the Links rather than uploading the file.

You can now view images at higher resolution in Photos. Upload JPG and GIF into Photos. Please convert BMP or TIF to JPG or GIF before uploading.

And please trim all this when replying! Yahoo! Groups Links

Re: Interesting Loop Antenna On Ebay

Richard Zolla

#3498

Strange, I just type in "Bodine loop" in the search and there it is!!!

--- In loopantennas@..., van lincoln <vlincoln@...> wrote:

here's the link:

van lincoln wd8aam

At 09:01 AM 5/20/2007 -0000, you wrote:
--- In loopantennas@..., "portstevos" <portstevos@>wrote:

--- In loopantennas@..., "Richard Zolla" <N8NKN@>wrote:

Loops have been around for quite a while.
Check out the "Bodine Loop" on Ebay.

N6NKN
I had a search on ebay but could not find it, can you pleasegive me
some further details or send me the link?

Thanks and best wishes from Australia!

Michael S

I couldn't find it on ebay either. But Google yielded this charming item:

(Bottom left, c. 1926)

Regards, Paul Norman (Left Coast)

If you've got links, post them in the Links section!

Post files here. If the file comes from a website, please put itin the
Links rather than uploading the file.

You can now view images at higher resolution in Photos. Upload JPGand GIF
into Photos. Please convert BMP or TIF to JPG or GIF beforeuploading.

And please trim all this when replying!
Yahoo! Groups Links

Re: Interesting Loop Antenna On Ebay

van lincoln

#3497

here's the link:

van lincoln wd8aam

At 09:01 AM 5/20/2007 -0000, you wrote:
--- In loopantennas@..., "portstevos" <portstevos@...> wrote:

--- In loopantennas@..., "Richard Zolla" <N8NKN@> wrote:

Loops have been around for quite a while.
Check out the "Bodine Loop" on Ebay.

N6NKN
I had a search on ebay but could not find it, can you please give me
some further details or send me the link?

Thanks and best wishes from Australia!

Michael S

I couldn't find it on ebay either. But Google yielded this charming item:

(Bottom left, c. 1926)

Regards, Paul Norman (Left Coast)

If you've got links, post them in the Links section!

Post files here. If the file comes from a website, please put it in theLinks rather than uploading the file.

You can now view images at higher resolution in Photos. Upload JPG and GIFinto Photos. Please convert BMP or TIF to JPG or GIF before uploading.

And please trim all this when replying! 
Yahoo! Groups Links

Building my first loop

#3495

I am in the parts gathering stage to building my first loop.  I have
picked up a 4 section tuning capacitor 280 uuf per section.  I am not
sure if I should connect each section in series and connect the antenna
to the first ant last section or is there a better way to wire this.
Thanks Ed Dawson

Re: Building my first loop

[email protected]

#3501

In a message dated 20/05/2007 16:39:19 GMT Daylight Time,  
ewdawso_1@... writes:

I am  in the parts gathering stage to building my first loop. I have 
picked up a  4 section tuning capacitor 280 uuf per section. I am not 
sure if I should  connect each section in series and connect the antenna 
to the first ant  last section or is there a better way to wire this. 
Thanks Ed  Dawson


---------------------------------------------------
 
Hi Ed
 
If you wire all your capacitor sections in series you'll reduce your  maximum 
capacitance to 70pF, capacitors in series act in a similar fashion to  
resistors in parallel.
 
If you want to increase capacitance you need to wire them in  parallel.
 
If, as sometimes happen, the capacitors share a common ground terminal then  
wiring them in series wouldn't be an option anyway.
 
How to wire them depends on the loop and the frequency range you want  to 
cover but a reasonable general solution for experimantation might be to wire  one 
section across the loop and then wire a switch so as to add the other  
sections in parallel one at a time.
This will give you full range swings of 0 to 280, 0 to 560, 0 to 840, and 0  
to 1120, which is quite a range.
 
Note that the "0" in each case is theoretical only, in practice there will  
always be some residual capacitance at the minimum setting, that will again  
increase as more sections are added in parallel.
 
regards
 
Nigel
GM8PZR

Re: Interesting Loop Antenna On Ebay

Paul Norman

#3496

--- In loopantennas@..., "Fraser" <fraser.castle@...> wrote:

I had a search on ebay but could not find it, can you please give me
some further details or send me the link?

Thanks and best wishes from Australia!

Michael S
It's on ebay.com

Look here:

1925_W0QQitemZ180117646543QQihZ008QQcategoryZ38033QQssPageNameZWDVWQQrdZ
1QQcmdZViewItem

Fraser

That URL broke up and I couldn't seem to mend it. But here's what one
looks like: 

Paul Norman [Seattle, Left Coast]

开云体育