Dipole Extension
 

I have an old (but very good) W9INN 40/80 dipole. The only problem is
it is cut for the upper phone band (centered at ~7.200) for 40 meters
and I now do most operating in the lower portion of the band and would
like to move the center to about 7.100 MHz. The 40 meter portion of the
antenna is all soldered so I cannot just unwrap and extend it bit.

Any suggestions on the best way to add a extension and how much to add?

I have been thinking about cutting it and soldering in an X?-inch
splice. Does the extension wire have to really match?

Dick AA5VU

Dipole Extension
 

I am not familiar with your 40/80 dipole, I assume it is a trap
arrangement.

The 1/2 wave difference on 40M of 7.2 and 7.1mhz is only about a foot.
The change in a DIPOLE at 40M would be difficult to measure.

I would not change it.
Do you have an indication that it needs adjustment?

On Fri, 10 Mar 2006 12:55:55 GMT, "Dick, AA5VU"
wrote:

I have an old (but very good) W9INN 40/80 dipole. The only problem is
it is cut for the upper phone band (centered at ~7.200) for 40 meters
and I now do most operating in the lower portion of the band and would
like to move the center to about 7.100 MHz. The 40 meter portion of the
antenna is all soldered so I cannot just unwrap and extend it bit.

Any suggestions on the best way to add a extension and how much to add?

I have been thinking about cutting it and soldering in an X?-inch
splice. Does the extension wire have to really match?

Dick AA5VU
John Ferrell W8CCW

Dipole Extension
 

On Fri, 10 Mar 2006 12:55:55 GMT, "Dick, AA5VU"
wrote:

I have an old (but very good) W9INN 40/80 dipole. The only problem is
it is cut for the upper phone band (centered at ~7.200) for 40 meters
and I now do most operating in the lower portion of the band and would
like to move the center to about 7.100 MHz. The 40 meter portion of the
antenna is all soldered so I cannot just unwrap and extend it bit.

Any suggestions on the best way to add a extension and how much to add?

I have been thinking about cutting it and soldering in an X?-inch
splice. Does the extension wire have to really match?

Dick AA5VU

I've added extensions via an alligator clip with a piece of wire
attached, and then shorten that wire until you get a good match.

bob
k5qwg

Dipole Extension
 

In article ,
John Ferrell wrote:

The 1/2 wave difference on 40M of 7.2 and 7.1mhz is only about a foot.
The change in a DIPOLE at 40M would be difficult to measure.

I would not change it.
Do you have an indication that it needs adjustment?

John,

When i trimmed it the first time (years ago) I was working mostly SSB so
it is great in phone band and okay in the old Novice portion. I am now
working mostly 40 meter RTTY and PSK and these are at 7.070 and 7.035.

The current antenna shows SWR of about 1:8 at 7.100 and goes up to
2:0 at 7.050. My TS-570S tuner makes the rig smile but I feel it would
be better if I could extend it a bit.

The problem is there is no wrapped back wire that I could let out and
hate to use a jumper extender at the loading coil.

I may have to just bit the bullet and cut some wire per the formulas by
Steve, K9DCI, and solder it in the middle some place.

Still thinking about it. The WX in South Texas is too nice for antenna
work. I will probably put it off until the WX is bad.

73, Dick AA5VU

Dipole Extension
 

Dick, AA5VU wrote:
The current antenna shows SWR of about 1:8 at 7.100 and goes up to
2:0 at 7.050. My TS-570S tuner makes the rig smile but I feel it would
be better if I could extend it a bit.

If you enjoy lowering your SWR below 2:1, go for it. If you
think it will help the ham on the other end copy you better,
you are, as someone has said before, picking fly spots out
of black pepper.
--
73, Cecil http://www.qsl.net/w5dxp

Dipole Extension
 

"Dick, AA5VU" wrote in message
...
In article ,
John Ferrell wrote:

The 1/2 wave difference on 40M of 7.2 and 7.1mhz is only about a foot.
The change in a DIPOLE at 40M would be difficult to measure.

I would not change it.
Do you have an indication that it needs adjustment?

John,

When i trimmed it the first time (years ago) I was working mostly SSB so
it is great in phone band and okay in the old Novice portion. I am now
working mostly 40 meter RTTY and PSK and these are at 7.070 and 7.035.

The current antenna shows SWR of about 1:8 at 7.100 and goes up to
2:0 at 7.050. My TS-570S tuner makes the rig smile but I feel it would
be better if I could extend it a bit.

The problem is there is no wrapped back wire that I could let out and
hate to use a jumper extender at the loading coil.

I may have to just bit the bullet and cut some wire per the formulas by
Steve, K9DCI, and solder it in the middle some place.

Still thinking about it. The WX in South Texas is too nice for antenna
work. I will probably put it off until the WX is bad.

73, Dick AA5VU

I am not familair with this antenna, but if it has a choke/trap for 40M,
just add a foot of wire on the side of the choke/trap that is closest to the
center insulator- let it hang down and dangle. You can clip it on as one
poster said- this is a high Z point and contact resistance is a non-issue.
But as others have said, the on-air difference is zero.

Dale W4OP

Dipole Extension
 

I agree on the part about the wx.
I doubt the antenna is really centered on 7.2 if it is up to 2:1 at
7.050. IF I were going to try to change anything, I would go to the
hardware store electrical department and get a couple of screw type
wire splices that are intended to splice about 12 ga. wire. Get the
type that come apart so that you don't have to cut the antenna to
string them on the wire. Alligator clips don't weather well here. You
can add a foot on each end of the 40M section and trim from there. I
hope the antenna goes up & down easy!

I would keep tabs on what is happening to the 80M operation as I went.
The environment around the antenna (height above ground, quality of
ground) may lead to erratic measurements. 2:1 is not a bad SWR. Your
ability to tune it out fixes everything except the losses in the tuner
and I doubt if they are high enough to consider!

Before you take any advice from me remember I consider myself an
antenna student, not an expert!

On Fri, 10 Mar 2006 20:24:41 GMT, "Dick, AA5VU"
wrote:

In article ,
John Ferrell wrote:

The 1/2 wave difference on 40M of 7.2 and 7.1mhz is only about a foot.
The change in a DIPOLE at 40M would be difficult to measure.

I would not change it.
Do you have an indication that it needs adjustment?

John,

When i trimmed it the first time (years ago) I was working mostly SSB so
it is great in phone band and okay in the old Novice portion. I am now
working mostly 40 meter RTTY and PSK and these are at 7.070 and 7.035.

The current antenna shows SWR of about 1:8 at 7.100 and goes up to
2:0 at 7.050. My TS-570S tuner makes the rig smile but I feel it would
be better if I could extend it a bit.

The problem is there is no wrapped back wire that I could let out and
hate to use a jumper extender at the loading coil.

I may have to just bit the bullet and cut some wire per the formulas by
Steve, K9DCI, and solder it in the middle some place.

Still thinking about it. The WX in South Texas is too nice for antenna
work. I will probably put it off until the WX is bad.

73, Dick AA5VU
John Ferrell W8CCW

Dipole Extension
 

In article T8mQf.913$_f4.191@trnddc03,
"Dale Parfitt" wrote:

I am not familair with this antenna, but if it has a choke/trap for 40M,
just add a foot of wire on the side of the choke/trap that is closest to the
center insulator- let it hang down and dangle. You can clip it on as one
poster said- this is a high Z point and contact resistance is a non-issue.
But as others have said, the on-air difference is zero.

Dale W4OP

Late yesterday afternoon I decided to try the two alligator clips and
some wire to run a test to see what would happen. Sounds easy but I
made it very hard. To make a long shaggy-dog story short I added the
wire and the SWR went out of sight. It acted like a dead short. I then
lowered he antenna and cut the wire in half and it was still terrible.
I then trashed he alligator clips and wire to and it was still
terrible. After two hours of screwing around, I found some dummy (me)
had the coax switch on the old Ringo Ranger rather than the W9INN
antenna. By this time it was too dark to mess with anything.

Going to start over when the sun comes up but this time I plan to ditch
the alligator clips and attach a one foot wire using the connection nuts
on the coil/trap or whatever w9inn used to call that thing between the
40 and 80 wires and will have the coax switch on the right antenna this
time.

Dick AA5VU (red-faced)

Dipole Extension
 

In article ,
Cecil Moore wrote:

Dick, AA5VU wrote:
The current antenna shows SWR of about 1:8 at 7.100 and goes up to
2:0 at 7.050. My TS-570S tuner makes the rig smile but I feel it would
be better if I could extend it a bit.

If you enjoy lowering your SWR below 2:1, go for it. If you
think it will help the ham on the other end copy you better,
you are, as someone has said before, picking fly spots out
of black pepper.

Cecil,

You are correct but many of us tend to get obsessive about SWR. The
enemy of good is better and many of us have wasted hours trying to make
a good antenna better. It is part of being a ham.

Dick AA5VU

Dipole Extension
 

"Dick, AA5VU" wrote:


Late yesterday afternoon I decided to try the two alligator clips and
some wire to run a test to see what would happen. Sounds easy but I
made it very hard.

Dick AA5VU (red-faced)

Atta Ham! :-) I'm pretty sure we've all done things like that! At
least I have -- more than once too!

Irv VE6BP
--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/index.html
Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm
Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada

Dipole Extension
 

"aRKay" wrote
You are correct but many of us tend to get obsessive about SWR.

=====================================

Quite right too!

Extremely few SWR meters indicate SWR on the transmission line from
transmitter to the antenna where it really might matter but seldom
doesn't.

All that is indicated is whether or not the transmitter is loaded with
its correct impedance. Admittedly, a useful indication.

The learned discussions on the subject of interpretting SWR meter
redings are usually so much baffle-gab.
----
Reg.

Dipole Extension (done)
 

In article
,
"Dick, AA5VU" wrote:

In article T8mQf.913$_f4.191@trnddc03,
"Dale Parfitt" wrote:

I am not familair with this antenna, but if it has a choke/trap for 40M,
just add a foot of wire on the side of the choke/trap that is closest to
the
center insulator- let it hang down and dangle. You can clip it on as one
poster said- this is a high Z point and contact resistance is a non-issue.
But as others have said, the on-air difference is zero.

Dale W4OP

Late yesterday afternoon I decided to try the two alligator clips and
some wire to run a test to see what would happen. Sounds easy but I
made it very hard. To make a long shaggy-dog story short I added the
wire and the SWR went out of sight. It acted like a dead short. I then
lowered he antenna and cut the wire in half and it was still terrible.
I then trashed he alligator clips and wire to and it was still
terrible. After two hours of screwing around, I found some dummy (me)
had the coax switch on the old Ringo Ranger rather than the W9INN
antenna. By this time it was too dark to mess with anything.

Going to start over when the sun comes up but this time I plan to ditch
the alligator clips and attach a one foot wire using the connection nuts
on the coil/trap or whatever w9inn used to call that thing between the
40 and 80 wires and will have the coax switch on the right antenna this
time.

Dick AA5VU (red-faced)

The antenna now lives! This morning I added a 14-inch wire to each leg
by attaching it to nut on the 40 meter side of coil/trap thing. The
experiment worked so I know how much I need to cut and solder in on he
40 meter dipole. I may run with the 14-inch wire whips for a week or so
and see what happens. The following is a list of the before and after
SWR readings. The 14" addition did just what the book said it would do.
I now have the 40 meter resonant point pretty close to where I want it
for PSK and RTTY but can still use the phone band as well.

7.600 1.8
7.500 1.4 2.0
7.400 1.1 1.8
7.300 1.1 1.3
7.200 1.4 1.1
7.100 1.7 1.1
7.050 1.8 1.3
7.000 1.8 1.4
6.900 2.0 1.6
6.800 - 2.0

The 50 MHz, 18 MHz, 24 MHz and 3.9 MHz readings did not change and
they are all 1.1 or very close.

Bill, W9INN, will be missed. He was a great guy and his antennas were
excellent. Too bad nobody picked up the ball from him. My old 40/80
W9INN has been modified to add WARC bands but still works great after 20
years of use and abuse. The traps are still in good shape.

TNX for reading

73, Dick AA5VU

Dipole Extension (done)
 

I am glad to hear it now meets your expectations. I still have not
found a diagram of your antenna, but I did find this very good artical
on SWR:
http://www.qsl.net/k2hq/swr.htm#PART%201

On Sat, 11 Mar 2006 21:00:00 GMT, "Dick, AA5VU"
wrote:



The antenna now lives! This morning I added a 14-inch wire to each leg
by attaching it to nut on the 40 meter side of coil/trap thing. The
experiment worked so I know how much I need to cut and solder in on he
40 meter dipole. I may run with the 14-inch wire whips for a week or so
and see what happens. The following is a list of the before and after
SWR readings. The 14" addition did just what the book said it would do.
I now have the 40 meter resonant point pretty close to where I want it
for PSK and RTTY but can still use the phone band as well.

7.600 1.8
7.500 1.4 2.0
7.400 1.1 1.8
7.300 1.1 1.3
7.200 1.4 1.1
7.100 1.7 1.1
7.050 1.8 1.3
7.000 1.8 1.4
6.900 2.0 1.6
6.800 - 2.0

The 50 MHz, 18 MHz, 24 MHz and 3.9 MHz readings did not change and
they are all 1.1 or very close.

Bill, W9INN, will be missed. He was a great guy and his antennas were
excellent. Too bad nobody picked up the ball from him. My old 40/80
W9INN has been modified to add WARC bands but still works great after 20
years of use and abuse. The traps are still in good shape.

TNX for reading

73, Dick AA5VU
John Ferrell W8CCW

Dipole Extension (done)
 

I am not familair with this antenna, but if it has a choke/trap for
40M,
just add a foot of wire on the side of the choke/trap that is closest
to
the
center insulator- let it hang down and dangle. You can clip it on as
one
poster said- this is a high Z point and contact resistance is a
non-issue.
But as others have said, the on-air difference is zero.

Dale W4OP


The antenna now lives! This morning I added a 14-inch wire to each leg
by attaching it to nut on the 40 meter side of coil/trap thing. The
experiment worked so I know how much I need to cut and solder in on he
40 meter dipole. I may run with the 14-inch wire whips for a week or so
and see what happens. The following is a list of the before and after
SWR readings. The 14" addition did just what the book said it would do.
I now have the 40 meter resonant point pretty close to where I want it
for PSK and RTTY but can still use the phone band as well.

Absolutely zero reason to place that wire in series with the dipole- in fact
it will not yield the same results if you do so- you will end up having to
redo the length. It will also mechanically weaken the antenna and also
change 80M resonance. There is no current in that short stub-i.e. no effect
on radiation. Let it dangle.
Dale W4OP

Dipole Extension (done)
 

In article 2%HQf.12296$wH5.7544@trnddc02,
"Dale Parfitt" wrote:

Absolutely zero reason to place that wire in series with the dipole- in fact
it will not yield the same results if you do so- you will end up having to
redo the length. It will also mechanically weaken the antenna and also
change 80M resonance. There is no current in that short stub-i.e. no effect
on radiation. Let it dangle.
Dale W4OP

Thanks..... going to let it dangle. Not hurting anything and it has a
good attachment.

Description of W9INN 40/80 dipole
 

Thanks for the description!

It sounds like a design worth copying.

On Sun, 12 Mar 2006 02:04:52 GMT, "Dick, AA5VU"
wrote:

In article ,
John Ferrell wrote:

I am glad to hear it now meets your expectations. I still have not
found a diagram of your antenna, but I did find this very good artical
on SWR:
http://www.qsl.net/k2hq/swr.htm#PART%201

John,

If you recall the old W9INN ads in QST you he has a 40/80 dipole. It
was full size 40 meter dipole with what I remember he called a resister
(that was really a coil) and about a 9 foot length of wire past the coil
for the 80 meter antenna. It was fed with coax to a center insulator.
Bill did not believe in baluns.

I modified the antenna by two sets of wires. One for 10 MHz and the
other for 18 MHz. The 18 MHz seems to be resonant for 6 meters and the
whole mess works on 24 MHz as well.

I did not see it on the K2HG web page

73, Dick AA5VU
John Ferrell W8CCW

Description of W9INN 40/80 dipole
 

ORIGINAL MESSAGE:

Dick, AA5VU wrote:

It
was full size 40 meter dipole with what I remember he called a
resister (that was really a coil)


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The word was "resonactor". I have one of his antennas and it works
fine.

I have not examined the resonactor in detail, but I believe it is just
an inductor which is carefully wound to be self-resonant at the desired
frequency, thereby eliminating the need for a separate capacitor to
resonate it. A clever idea, since eliminating the separate capacitor
easily allows full legal power without the expense of a very high
voltage capacitor.

W9INN's trap dipoles are the only ones I know of which advertise full
legal power handling, and that's why I purchased one. I've been running
full power RTTY on mine for five years with no problems.

Since I purchased mine there may have been other full power trap
dipoles come on the market. If anyone knows of one, please reply. I'm
always curious about such things.

Bill, W6WRT

Dipole Extension (done)
 

Bottom posted...

"Dick, AA5VU" wrote in message
...
In article 2%HQf.12296$wH5.7544@trnddc02,
"Dale Parfitt" wrote:

Absolutely zero reason to place that wire in series with the dipole- in
fact
it will not yield the same results if you do so- you will end up having
to
redo the length. It will also mechanically weaken the antenna and also
change 80M resonance. There is no current in that short stub-i.e. no
effect
on radiation. Let it dangle.
Dale W4OP

Thanks..... going to let it dangle. Not hurting anything and it has a
good attachment.

Hi Dick,

Dale has got it EXACTLY right here! Variable-length stubs from the
inboard screws on the "resonactors" is how Bill (W9INN) INTENDED
his antennas to be tuned! He called this--logically enough--"stub tuning."

The obvious advantages of stub tuning a
1. It's much easier than changing the length of the primary antenna wire,
and
2. The two (or more) bands can be adjusted INDEPENDENTLY of each
other; i.e., changing the length of the 40m stubs does not affect 80m
tuning; and changing the length of the 80m stubs does not affect 40m
tuning.

This is absolutely the right way to build dipoles in which precise tuning of
resonance is desired.

Now that you've got your 40m resonance set to mid-band, you're pretty
much done on 40m; you can get the full band under 2:1.

But 80m is another story. Because of the "resonactor" loading (which
conveniently reduces overall length), your 2:1 BW is probably 90 to 140 kHz.
By changing the 80m stubs, you can put this wherever you want in the 80m
band; but it's still pretty narrow.

I made a small mod on my W9INN 80/40/17 dipole by putting Rat Shack
banana sockets on the ends of the primary 80m stubs. This enables me to
swap stubs (each with its own banana plug), to move the 80m resonance
around in the band. Because my antenna is in an inverted vee configuration
with fairly low ends, it's easy for me to change the stub(s).

My normal tuning point is 3950 kHz, where I get 1:1 SWR. To move to
3850 kHz, I plug in ONE stub of appropriate length. (Absolute mechanical
symmetry isn't necessary; in fact, asymmetry in the preferred direction can
actually lower SWR.) It takes me 90 seconds to go from my second-floor
shack out to the antenna, make the change, and come back again.

Naturally, the WX is sometimes such that I don't want to go outside and
play with stubs. That's one reason I just replaced my trusty W9INN with
a Buckmaster OCF; but the Buckmaster is a subject for another thread.

73, Ed, W6LOL

Description of W9INN 40/80 dipole
 

You may want to check out the antenna advertising he
http://www.alphadeltacom.com/

It seems like your description.
I do not have an antenna for 160-80.
The DX-LB at $130 looks pretty good.

On 12 Mar 2006 17:48:03 -0500, "Bill Turner" wrote:

ORIGINAL MESSAGE:

Dick, AA5VU wrote:

It
was full size 40 meter dipole with what I remember he called a
resister (that was really a coil)


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~
The word was "resonactor". I have one of his antennas and it works
fine.

I have not examined the resonactor in detail, but I believe it is just
an inductor which is carefully wound to be self-resonant at the desired
frequency, thereby eliminating the need for a separate capacitor to
resonate it. A clever idea, since eliminating the separate capacitor
easily allows full legal power without the expense of a very high
voltage capacitor.

W9INN's trap dipoles are the only ones I know of which advertise full
legal power handling, and that's why I purchased one. I've been running
full power RTTY on mine for five years with no problems.

Since I purchased mine there may have been other full power trap
dipoles come on the market. If anyone knows of one, please reply. I'm
always curious about such things.

Bill, W6WRT
John Ferrell W8CCW

Description of W9INN 40/80 dipole
 

ORIGINAL MESSAGE:

John Ferrell wrote:


You may want to check out the antenna advertising he
http://www.alphadeltacom.com/

It seems like your description.
I do not have an antenna for 160-80.
The DX-LB at $130 looks pretty good.



*********** REPLY SEPARATOR ***********

Yes, that looks very similar to the W9INN design. Should be a good one.

73, Bill W6WRT

Description of W9INN 40/80 dipole
 

On 13 Mar 2006 21:50:53 -0500, "Bill Turner" wrote:

ORIGINAL MESSAGE:

John Ferrell wrote:


You may want to check out the antenna advertising he
http://www.alphadeltacom.com/

It seems like your description.
I do not have an antenna for 160-80.
The DX-LB at $130 looks pretty good.



*********** REPLY SEPARATOR ***********

Yes, that looks very similar to the W9INN design. Should be a good one.

73, Bill W6WRT

I had one of the Alpha Delta antennas many years ago; the inductors
were wound on ceramic or plastic forms, I forget which, but it was a
very well-built antenna.

bob
k5qwg