"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

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

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

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.

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