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 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

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

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

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

"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.

"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

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)

"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

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