Ian Jackson wrote:
In message , atec77
writes
Andy wrote:
"Ian Jackson" wrote in
message ...
In message , Andy
writes


"Ian Jackson" wrote in
message
...
Andy, is your endfed wire the one in your other thread of the 8th
June (ie
the 80 Meter End Fed, fed with coax at the far end)? If so,
presumably the
tuner is at the shack end. Or are you feeding it from the shack end.


In message , Andy
writes

--

Hi Ian,

Yes its the same. The tuner is at the shack end (house) and I'm
feeding the
antenna with 50 Ohm RG-58 C/U coax at the far end of the garden. If
I can
get it working well I will replace it with some RG-213 that I have
here. I
put it back up yesterday and started experimenting again.

The End Fed at the moment has 15 feet of 300 Ohm slotted ribbon
feeder. This
is all I had left spare. One side is connected to the wire antenna
and the
other side left, not connected. The coax is connected to the 300
Ohm at the
bottom and the braid side is now connected to the unconnected side
of the
300 Ohm and also to the earth ground rod.
On 80 the receive is up 2-4 S points compared with the 40m coax
Centre Fed
Dipole. I have not had chance to get any actual reports on 80 yet.
Maybe
this weekend.

73 Andy
OK, Andy. Noted.

I don't know if you will really improve things by using the 15 foot
of 300 ohm feeder. It's a sort of a zepp, but with one side of the
feeder earthed. I would try disconnecting the earthed
('unconnected') side from earth / coax braid. You can either leave
it floating, or connect it to the coax inner. It will then be
approximately a quarterwave on 20m, fed in parallel with the long
wire.

Don't read too much into the excellent SWR you're getting with the
tuner. That's what the TX sees, but the tuner can't affect the SWR
on the aerial feeder. If the coax SWR is sky high (and it can be if
the impedance at aerial feed point is high), the coax losses will
be much more that you would get compared with when it is matched
correctly. You only get away with it by using the lowest-loss you
can find, and keeping the coax as short as possible.

I'm not surprised that 80m on the endfed is a bit better than the
40m dipole. But what's 40m like on the endfed? That's when the feed
impedance (and coax SWR) will be very high, and where the RG-213
might perform better noticeably better than the RG-58.

As I think I said before, although I am an advocate of simply using
coax (regardless), after all these years I am considering in
investing in something like a SG230 remote tuner for the far end of
the coax.
-- Ian


Ian,
I'll have to do some experimenting with the 300 Ohm feeder and see
what happens. The End Fed on 40m is very poor indeed. I would say
unusable like it is.
The End Fed wire at the moment is resonate on 2. 682 MHz.
The funny thing is that when I cut the wire to bring the End Fed to
resonate on 80m, no matter how much wire I cut off it doesn't really
move from the 2.682 MHz. I have tried this with and with out the
ribbon feeder being in place and with coax connected direct and the
braid connected to the earth rod.
What would cause this?
I have no problem using the Analyser with my mobile and centre fed
dipoles.
73 Andy

adding a suitably cut wire counterpoise at +% for each band should
certainly assist things .

I rather think that Andy can't add counterpoises.
of course he can , he has a run of crap coax so when he replaces it
with some rg213 adding some multi strand suitably trimmed one be a
burden from the far coax connection back
A decent earthing
system should work
maybe there is a reason to not have one , with more description a
balun of some sort may prove most useful
(although additional counterpoises certainly won't do
any harm).

Re the 2.682MHz resonance, this may be because the coax is completely
mismatched at lots of frequencies, and what you're seeing this is
more-or-less a spurious resonance of the coax itself.
rg 58cu ? is kinda crap
Do you still get
it with the wire completely disconnected? Even with centre-fed dipoles,
you often get some very unexpected resonances way off frequency
(especially of you are doing a wideband frequency sweep of the return
loss / SWR).

As I said previously, persuading an approximate halfwave endfed (which
is what you have on 40m) to work with a coax feed is certainly not
ideal, but you can usually get it to work fairly well (with all the
provisos already discussed). My setup here is almost twice the size of
what you have, so the wire feed impedance will be low on 160m and I high
on 80m and 40m. 80m (corresponding to your 40m) is certainly lively
enough. On 40m, the performance does not seem to be unduly poor compared
with the signal reports swapped between others on the band.

So, Andy, I simply don't know why your 40m is so poor. Have you tried
(temporarily) reducing the length to around 33 feet, so that it is a
quarterwave on 40m? This should give a reasonable match for your coax
(at least, nothing you can't tune out back in the shack). If this is
more lively than the 64 feet, maybe you can try two wires in parallel.
This can be discussed later if the 33 feet shows promise. If a multiband
(and possibly compromise) aerial doesn't work well, it's a good idea to
try something simple which you know SHOULD work. The problem may lie
elsewhere.



Oh dear
Finally, can I ask you to follow the standard practice of bottom posting!
Cheers...

Oh, I think under the circumstances, that RG-58 isn't all that bad.
May not have the lowest losses possible, but certainly not complete
'crap'. Replacing it with something 'better' is certainly an option,
but not the first one I'd try.
Options.
Try all that you can think of and see what happens. If things are
'better' on one particular band doing it 'this' way, then I think I'd
note that when using that particular band. Repeat for the other
bands. Lots of work? Sure, but if it works, it works. Finding one
antenna that does it all is almost impossible. Too many variables
depending on each individual installation. But, if you get 'close',
that's probably as good as you can expect, depending on the
circumstances. Having the absolute 'best' antenna in the world is
certainly nice! It isn't absolutely necessary. Everyone goes through
this same sort of thingy. The results differ, but so do the
circumstances.
Good luck.
- 'Doc

"Ian Jackson" wrote in message
...
In message , atec77
writes
Andy wrote:
"Ian Jackson" wrote in
message ...
In message , Andy
writes


"Ian Jackson" wrote in
message
...
Andy, is your endfed wire the one in your other thread of the 8th
June (ie
the 80 Meter End Fed, fed with coax at the far end)? If so,
presumably the
tuner is at the shack end. Or are you feeding it from the shack end.


In message , Andy
writes

--

Hi Ian,

Yes its the same. The tuner is at the shack end (house) and I'm
feeding the
antenna with 50 Ohm RG-58 C/U coax at the far end of the garden. If I
can
get it working well I will replace it with some RG-213 that I have
here. I
put it back up yesterday and started experimenting again.

The End Fed at the moment has 15 feet of 300 Ohm slotted ribbon
feeder. This
is all I had left spare. One side is connected to the wire antenna and
the
other side left, not connected. The coax is connected to the 300 Ohm
at the
bottom and the braid side is now connected to the unconnected side of
the
300 Ohm and also to the earth ground rod.
On 80 the receive is up 2-4 S points compared with the 40m coax Centre
Fed
Dipole. I have not had chance to get any actual reports on 80 yet.
Maybe
this weekend.

73 Andy
OK, Andy. Noted.

I don't know if you will really improve things by using the 15 foot of
300 ohm feeder. It's a sort of a zepp, but with one side of the feeder
earthed. I would try disconnecting the earthed ('unconnected') side
from earth / coax braid. You can either leave it floating, or connect
it to the coax inner. It will then be approximately a quarterwave on
20m, fed in parallel with the long wire.

Don't read too much into the excellent SWR you're getting with the
tuner. That's what the TX sees, but the tuner can't affect the SWR on
the aerial feeder. If the coax SWR is sky high (and it can be if the
impedance at aerial feed point is high), the coax losses will be much
more that you would get compared with when it is matched correctly.
You only get away with it by using the lowest-loss you can find, and
keeping the coax as short as possible.

I'm not surprised that 80m on the endfed is a bit better than the 40m
dipole. But what's 40m like on the endfed? That's when the feed
impedance (and coax SWR) will be very high, and where the RG-213 might
perform better noticeably better than the RG-58.

As I think I said before, although I am an advocate of simply using
coax (regardless), after all these years I am considering in investing
in something like a SG230 remote tuner for the far end of the coax.
-- Ian


Ian,
I'll have to do some experimenting with the 300 Ohm feeder and see what
happens. The End Fed on 40m is very poor indeed. I would say unusable
like it is.
The End Fed wire at the moment is resonate on 2. 682 MHz.
The funny thing is that when I cut the wire to bring the End Fed to
resonate on 80m, no matter how much wire I cut off it doesn't really
move from the 2.682 MHz. I have tried this with and with out the ribbon
feeder being in place and with coax connected direct and the braid
connected to the earth rod.
What would cause this?
I have no problem using the Analyser with my mobile and centre fed
dipoles.
73 Andy

adding a suitably cut wire counterpoise at +% for each band should
certainly assist things .

I rather think that Andy can't add counterpoises. A decent earthing system
should work (although additional counterpoises certainly won't do any
harm).

Re the 2.682MHz resonance, this may be because the coax is completely
mismatched at lots of frequencies, and what you're seeing this is
more-or-less a spurious resonance of the coax itself. Do you still get it
with the wire completely disconnected? Even with centre-fed dipoles, you
often get some very unexpected resonances way off frequency (especially of
you are doing a wideband frequency sweep of the return loss / SWR).

As I said previously, persuading an approximate halfwave endfed (which is
what you have on 40m) to work with a coax feed is certainly not ideal, but
you can usually get it to work fairly well (with all the provisos already
discussed). My setup here is almost twice the size of what you have, so
the wire feed impedance will be low on 160m and I high on 80m and 40m. 80m
(corresponding to your 40m) is certainly lively enough. On 40m, the
performance does not seem to be unduly poor compared with the signal
reports swapped between others on the band.

So, Andy, I simply don't know why your 40m is so poor. Have you tried
(temporarily) reducing the length to around 33 feet, so that it is a
quarterwave on 40m? This should give a reasonable match for your coax (at
least, nothing you can't tune out back in the shack). If this is more
lively than the 64 feet, maybe you can try two wires in parallel. This can
be discussed later if the 33 feet shows promise. If a multiband (and
possibly compromise) aerial doesn't work well, it's a good idea to try
something simple which you know SHOULD work. The problem may lie
elsewhere.

Finally, can I ask you to follow the standard practice of bottom posting!
Cheers...
--
Ian

I've have just connected the Analyser at the feed point on the End fed wire.
The frequency is now at 2.898 MHz without coax being in line. I have just
tried
to shorten the Antenna again to bring the frequency closer to the 80m band,
but
it will not adjust from this frequency.

What's confusing me is that the End fed wire should be longer than a 1/4
wave on 80 and the frequency that it ended up on, that is now 2.898 would be
about right for the length. So why won't that frequency change when I start
trimming the wire down in size?
It just isn't making any sense to me. The resonant frequency surely should
change with the altered length.

73 Andy

In message , Andy
writes

"Ian Jackson" wrote in message
...
In message , atec77
writes
Andy wrote:
"Ian Jackson" wrote in
message ...
In message , Andy
writes


"Ian Jackson" wrote in
message
...
Andy, is your endfed wire the one in your other thread of the 8th
June (ie
the 80 Meter End Fed, fed with coax at the far end)? If so,
presumably the
tuner is at the shack end. Or are you feeding it from the shack end.


In message , Andy
writes

--

Hi Ian,

Yes its the same. The tuner is at the shack end (house) and I'm
feeding the
antenna with 50 Ohm RG-58 C/U coax at the far end of the garden. If I
can
get it working well I will replace it with some RG-213 that I have
here. I
put it back up yesterday and started experimenting again.

The End Fed at the moment has 15 feet of 300 Ohm slotted ribbon
feeder. This
is all I had left spare. One side is connected to the wire antenna and
the
other side left, not connected. The coax is connected to the 300 Ohm
at the
bottom and the braid side is now connected to the unconnected side of
the
300 Ohm and also to the earth ground rod.
On 80 the receive is up 2-4 S points compared with the 40m coax Centre
Fed
Dipole. I have not had chance to get any actual reports on 80 yet.
Maybe
this weekend.

73 Andy
OK, Andy. Noted.

I don't know if you will really improve things by using the 15 foot of
300 ohm feeder. It's a sort of a zepp, but with one side of the feeder
earthed. I would try disconnecting the earthed ('unconnected') side
from earth / coax braid. You can either leave it floating, or connect
it to the coax inner. It will then be approximately a quarterwave on
20m, fed in parallel with the long wire.

Don't read too much into the excellent SWR you're getting with the
tuner. That's what the TX sees, but the tuner can't affect the SWR on
the aerial feeder. If the coax SWR is sky high (and it can be if the
impedance at aerial feed point is high), the coax losses will be much
more that you would get compared with when it is matched correctly.
You only get away with it by using the lowest-loss you can find, and
keeping the coax as short as possible.

I'm not surprised that 80m on the endfed is a bit better than the 40m
dipole. But what's 40m like on the endfed? That's when the feed
impedance (and coax SWR) will be very high, and where the RG-213 might
perform better noticeably better than the RG-58.

As I think I said before, although I am an advocate of simply using
coax (regardless), after all these years I am considering in investing
in something like a SG230 remote tuner for the far end of the coax.
-- Ian


Ian,
I'll have to do some experimenting with the 300 Ohm feeder and see what
happens. The End Fed on 40m is very poor indeed. I would say unusable
like it is.
The End Fed wire at the moment is resonate on 2. 682 MHz.
The funny thing is that when I cut the wire to bring the End Fed to
resonate on 80m, no matter how much wire I cut off it doesn't really
move from the 2.682 MHz. I have tried this with and with out the ribbon
feeder being in place and with coax connected direct and the braid
connected to the earth rod.
What would cause this?
I have no problem using the Analyser with my mobile and centre fed
dipoles.
73 Andy

adding a suitably cut wire counterpoise at +% for each band should
certainly assist things .

I rather think that Andy can't add counterpoises. A decent earthing system
should work (although additional counterpoises certainly won't do any
harm).

Re the 2.682MHz resonance, this may be because the coax is completely
mismatched at lots of frequencies, and what you're seeing this is
more-or-less a spurious resonance of the coax itself. Do you still get it
with the wire completely disconnected? Even with centre-fed dipoles, you
often get some very unexpected resonances way off frequency (especially of
you are doing a wideband frequency sweep of the return loss / SWR).

As I said previously, persuading an approximate halfwave endfed (which is
what you have on 40m) to work with a coax feed is certainly not ideal, but
you can usually get it to work fairly well (with all the provisos already
discussed). My setup here is almost twice the size of what you have, so
the wire feed impedance will be low on 160m and I high on 80m and 40m. 80m
(corresponding to your 40m) is certainly lively enough. On 40m, the
performance does not seem to be unduly poor compared with the signal
reports swapped between others on the band.

So, Andy, I simply don't know why your 40m is so poor. Have you tried
(temporarily) reducing the length to around 33 feet, so that it is a
quarterwave on 40m? This should give a reasonable match for your coax (at
least, nothing you can't tune out back in the shack). If this is more
lively than the 64 feet, maybe you can try two wires in parallel. This can
be discussed later if the 33 feet shows promise. If a multiband (and
possibly compromise) aerial doesn't work well, it's a good idea to try
something simple which you know SHOULD work. The problem may lie
elsewhere.

Finally, can I ask you to follow the standard practice of bottom posting!
Cheers...
--
Ian

I've have just connected the Analyser at the feed point on the End fed wire.
The frequency is now at 2.898 MHz without coax being in line. I have just
tried
to shorten the Antenna again to bring the frequency closer to the 80m band,
but
it will not adjust from this frequency.

Ummmm...
Obviously something is wrong. It looks like your analyser is simply
telling lies. Could it have a spurious resonance at this frequency?

What's confusing me is that the End fed wire should be longer than a 1/4
wave on 80
and the frequency that it ended up on, that is now 2.898 would be
about right for the length.

A quarterwave on 80m is around 66 feet. Your 63 feet is actually a bit
on the short side. Being only 20 feet up may pull the resonance a bit
lower, but I doubt is could be anywhere as low as 2.898MHz.

So why won't that frequency change when I start
trimming the wire down in size?
It just isn't making any sense to me. The resonant frequency surely should
change with the altered length.

If shortening the aerial doesn't change the frequency, I don't think
your analyser is measuring the aerial. This is indeed a puzzle. As I
suggested before, you could go from the sublime to the ridiculous, and
try something like 33 feet, which should resonate at around 7MHz. If it
sticks at 2.898MHz, something is seriously amiss.

--
Ian

"Ian Jackson" wrote in message
...
In message , Andy
writes

"Ian Jackson" wrote in message
...
In message , atec77
writes
Andy wrote:
"Ian Jackson" wrote in
message ...
In message , Andy
writes


"Ian Jackson" wrote in
message
...
Andy, is your endfed wire the one in your other thread of the 8th
June (ie
the 80 Meter End Fed, fed with coax at the far end)? If so,
presumably the
tuner is at the shack end. Or are you feeding it from the shack
end.


In message , Andy
writes

--

Hi Ian,

Yes its the same. The tuner is at the shack end (house) and I'm
feeding the
antenna with 50 Ohm RG-58 C/U coax at the far end of the garden. If
I
can
get it working well I will replace it with some RG-213 that I have
here. I
put it back up yesterday and started experimenting again.

The End Fed at the moment has 15 feet of 300 Ohm slotted ribbon
feeder. This
is all I had left spare. One side is connected to the wire antenna
and
the
other side left, not connected. The coax is connected to the 300 Ohm
at the
bottom and the braid side is now connected to the unconnected side
of
the
300 Ohm and also to the earth ground rod.
On 80 the receive is up 2-4 S points compared with the 40m coax
Centre
Fed
Dipole. I have not had chance to get any actual reports on 80 yet.
Maybe
this weekend.

73 Andy
OK, Andy. Noted.

I don't know if you will really improve things by using the 15 foot
of
300 ohm feeder. It's a sort of a zepp, but with one side of the
feeder
earthed. I would try disconnecting the earthed ('unconnected') side
from earth / coax braid. You can either leave it floating, or
connect
it to the coax inner. It will then be approximately a quarterwave on
20m, fed in parallel with the long wire.

Don't read too much into the excellent SWR you're getting with the
tuner. That's what the TX sees, but the tuner can't affect the SWR
on
the aerial feeder. If the coax SWR is sky high (and it can be if the
impedance at aerial feed point is high), the coax losses will be
much
more that you would get compared with when it is matched correctly.
You only get away with it by using the lowest-loss you can find, and
keeping the coax as short as possible.

I'm not surprised that 80m on the endfed is a bit better than the 40m
dipole. But what's 40m like on the endfed? That's when the feed
impedance (and coax SWR) will be very high, and where the RG-213
might
perform better noticeably better than the RG-58.

As I think I said before, although I am an advocate of simply using
coax (regardless), after all these years I am considering in
investing
in something like a SG230 remote tuner for the far end of the coax.
-- Ian


Ian,
I'll have to do some experimenting with the 300 Ohm feeder and see
what
happens. The End Fed on 40m is very poor indeed. I would say unusable
like it is.
The End Fed wire at the moment is resonate on 2. 682 MHz.
The funny thing is that when I cut the wire to bring the End Fed to
resonate on 80m, no matter how much wire I cut off it doesn't really
move from the 2.682 MHz. I have tried this with and with out the
ribbon
feeder being in place and with coax connected direct and the braid
connected to the earth rod.
What would cause this?
I have no problem using the Analyser with my mobile and centre fed
dipoles.
73 Andy

adding a suitably cut wire counterpoise at +% for each band should
certainly assist things .

I rather think that Andy can't add counterpoises. A decent earthing
system
should work (although additional counterpoises certainly won't do any
harm).

Re the 2.682MHz resonance, this may be because the coax is completely
mismatched at lots of frequencies, and what you're seeing this is
more-or-less a spurious resonance of the coax itself. Do you still get
it
with the wire completely disconnected? Even with centre-fed dipoles, you
often get some very unexpected resonances way off frequency (especially
of
you are doing a wideband frequency sweep of the return loss / SWR).

As I said previously, persuading an approximate halfwave endfed (which
is
what you have on 40m) to work with a coax feed is certainly not ideal,
but
you can usually get it to work fairly well (with all the provisos
already
discussed). My setup here is almost twice the size of what you have, so
the wire feed impedance will be low on 160m and I high on 80m and 40m.
80m
(corresponding to your 40m) is certainly lively enough. On 40m, the
performance does not seem to be unduly poor compared with the signal
reports swapped between others on the band.

So, Andy, I simply don't know why your 40m is so poor. Have you tried
(temporarily) reducing the length to around 33 feet, so that it is a
quarterwave on 40m? This should give a reasonable match for your coax
(at
least, nothing you can't tune out back in the shack). If this is more
lively than the 64 feet, maybe you can try two wires in parallel. This
can
be discussed later if the 33 feet shows promise. If a multiband (and
possibly compromise) aerial doesn't work well, it's a good idea to try
something simple which you know SHOULD work. The problem may lie
elsewhere.

Finally, can I ask you to follow the standard practice of bottom
posting!
Cheers...
--
Ian

I've have just connected the Analyser at the feed point on the End fed
wire.
The frequency is now at 2.898 MHz without coax being in line. I have just
tried
to shorten the Antenna again to bring the frequency closer to the 80m
band,
but
it will not adjust from this frequency.

Ummmm...
Obviously something is wrong. It looks like your analyser is simply
telling lies. Could it have a spurious resonance at this frequency?

What's confusing me is that the End fed wire should be longer than a 1/4
wave on 80
and the frequency that it ended up on, that is now 2.898 would be
about right for the length.

A quarterwave on 80m is around 66 feet. Your 63 feet is actually a bit on
the short side. Being only 20 feet up may pull the resonance a bit lower,
but I doubt is could be anywhere as low as 2.898MHz.

So why won't that frequency change when I start
trimming the wire down in size?
It just isn't making any sense to me. The resonant frequency surely should
change with the altered length.

If shortening the aerial doesn't change the frequency, I don't think your
analyser is measuring the aerial. This is indeed a puzzle. As I suggested
before, you could go from the sublime to the ridiculous, and try something
like 33 feet, which should resonate at around 7MHz. If it sticks at
2.898MHz, something is seriously amiss.

--
Ian

MFJ Analyser ????

Isolate the transmission line (coax) from the antenna, ie; UGLY BALUN, Line
Isolator

analyser may have copted a nose full of RF from the braid of feedline,
with such a mismatch

should build resonant antennas first, before inserting giant matcher, just
to see how much of your RF is dissipated in the match box. TX and RX

I haven't had time to try a 33" End fed to see if it would tune on 40m .But
I did have time to connect a temp 60 feet of wire from the top of the ribbon
feeder on the braid side to make a close 63 feet centre fed dipole fed with
300 Ohm feeder and the antenna resonates at 3.780 MHz with a 1.1:1 and the
AT1KP backs this reading up. I haven't tried to lengthen or shorten the
antenna yet. To see if it changes resonance, but I will do tomorrow.

It can't stay like that unfortunately.

So either my Analyser doesn't like to read End Fed antennas or there
something else causing the funny readings. If the Analyser senses the change
in frequency tomorrow when I start lengthening the antenna then it must be
working OK or there is a fault with it and it can't read End Fed wires
correctly. Is this even possible considering its reading everything else
correct.

What do you think?

73 Andy


"Ian Jackson" wrote in message
...
In message , Andy
writes

"Ian Jackson" wrote in message
...
In message , atec77
writes
Andy wrote:
"Ian Jackson" wrote in
message ...
In message , Andy
writes


"Ian Jackson" wrote in
message
...
Andy, is your endfed wire the one in your other thread of the 8th
June (ie
the 80 Meter End Fed, fed with coax at the far end)? If so,
presumably the
tuner is at the shack end. Or are you feeding it from the shack
end.


In message , Andy
writes

--

Hi Ian,

Yes its the same. The tuner is at the shack end (house) and I'm
feeding the
antenna with 50 Ohm RG-58 C/U coax at the far end of the garden. If
I
can
get it working well I will replace it with some RG-213 that I have
here. I
put it back up yesterday and started experimenting again.

The End Fed at the moment has 15 feet of 300 Ohm slotted ribbon
feeder. This
is all I had left spare. One side is connected to the wire antenna
and
the
other side left, not connected. The coax is connected to the 300 Ohm
at the
bottom and the braid side is now connected to the unconnected side
of
the
300 Ohm and also to the earth ground rod.
On 80 the receive is up 2-4 S points compared with the 40m coax
Centre
Fed
Dipole. I have not had chance to get any actual reports on 80 yet.
Maybe
this weekend.

73 Andy
OK, Andy. Noted.

I don't know if you will really improve things by using the 15 foot
of
300 ohm feeder. It's a sort of a zepp, but with one side of the
feeder
earthed. I would try disconnecting the earthed ('unconnected') side
from earth / coax braid. You can either leave it floating, or
connect
it to the coax inner. It will then be approximately a quarterwave on
20m, fed in parallel with the long wire.

Don't read too much into the excellent SWR you're getting with the
tuner. That's what the TX sees, but the tuner can't affect the SWR
on
the aerial feeder. If the coax SWR is sky high (and it can be if the
impedance at aerial feed point is high), the coax losses will be
much
more that you would get compared with when it is matched correctly.
You only get away with it by using the lowest-loss you can find, and
keeping the coax as short as possible.

I'm not surprised that 80m on the endfed is a bit better than the 40m
dipole. But what's 40m like on the endfed? That's when the feed
impedance (and coax SWR) will be very high, and where the RG-213
might
perform better noticeably better than the RG-58.

As I think I said before, although I am an advocate of simply using
coax (regardless), after all these years I am considering in
investing
in something like a SG230 remote tuner for the far end of the coax.
-- Ian


Ian,
I'll have to do some experimenting with the 300 Ohm feeder and see
what
happens. The End Fed on 40m is very poor indeed. I would say unusable
like it is.
The End Fed wire at the moment is resonate on 2. 682 MHz.
The funny thing is that when I cut the wire to bring the End Fed to
resonate on 80m, no matter how much wire I cut off it doesn't really
move from the 2.682 MHz. I have tried this with and with out the
ribbon
feeder being in place and with coax connected direct and the braid
connected to the earth rod.
What would cause this?
I have no problem using the Analyser with my mobile and centre fed
dipoles.
73 Andy

adding a suitably cut wire counterpoise at +% for each band should
certainly assist things .

I rather think that Andy can't add counterpoises. A decent earthing
system
should work (although additional counterpoises certainly won't do any
harm).

Re the 2.682MHz resonance, this may be because the coax is completely
mismatched at lots of frequencies, and what you're seeing this is
more-or-less a spurious resonance of the coax itself. Do you still get
it
with the wire completely disconnected? Even with centre-fed dipoles, you
often get some very unexpected resonances way off frequency (especially
of
you are doing a wideband frequency sweep of the return loss / SWR).

As I said previously, persuading an approximate halfwave endfed (which
is
what you have on 40m) to work with a coax feed is certainly not ideal,
but
you can usually get it to work fairly well (with all the provisos
already
discussed). My setup here is almost twice the size of what you have, so
the wire feed impedance will be low on 160m and I high on 80m and 40m.
80m
(corresponding to your 40m) is certainly lively enough. On 40m, the
performance does not seem to be unduly poor compared with the signal
reports swapped between others on the band.

So, Andy, I simply don't know why your 40m is so poor. Have you tried
(temporarily) reducing the length to around 33 feet, so that it is a
quarterwave on 40m? This should give a reasonable match for your coax
(at
least, nothing you can't tune out back in the shack). If this is more
lively than the 64 feet, maybe you can try two wires in parallel. This
can
be discussed later if the 33 feet shows promise. If a multiband (and
possibly compromise) aerial doesn't work well, it's a good idea to try
something simple which you know SHOULD work. The problem may lie
elsewhere.

Finally, can I ask you to follow the standard practice of bottom
posting!
Cheers...
--
Ian

I've have just connected the Analyser at the feed point on the End fed
wire.
The frequency is now at 2.898 MHz without coax being in line. I have just
tried
to shorten the Antenna again to bring the frequency closer to the 80m
band,
but
it will not adjust from this frequency.

Ummmm...
Obviously something is wrong. It looks like your analyser is simply
telling lies. Could it have a spurious resonance at this frequency?

What's confusing me is that the End fed wire should be longer than a 1/4
wave on 80
and the frequency that it ended up on, that is now 2.898 would be
about right for the length.

A quarterwave on 80m is around 66 feet. Your 63 feet is actually a bit on
the short side. Being only 20 feet up may pull the resonance a bit lower,
but I doubt is could be anywhere as low as 2.898MHz.

So why won't that frequency change when I start
trimming the wire down in size?
It just isn't making any sense to me. The resonant frequency surely should
change with the altered length.

If shortening the aerial doesn't change the frequency, I don't think your
analyser is measuring the aerial. This is indeed a puzzle. As I suggested
before, you could go from the sublime to the ridiculous, and try something
like 33 feet, which should resonate at around 7MHz. If it sticks at
2.898MHz, something is seriously amiss.

--
Ian

Albert,

I will tomorrow see if I have a spare 21" of coax handy to make one.

73 Andy


"Albert" wrote in message
node...

"Ian Jackson" wrote in message
...
In message , Andy
writes

"Ian Jackson" wrote in message
...
In message , atec77
writes
Andy wrote:
"Ian Jackson" wrote in
message ...
In message , Andy
writes


"Ian Jackson" wrote in
message
...
Andy, is your endfed wire the one in your other thread of the 8th
June (ie
the 80 Meter End Fed, fed with coax at the far end)? If so,
presumably the
tuner is at the shack end. Or are you feeding it from the shack
end.


In message , Andy
writes

--

Hi Ian,

Yes its the same. The tuner is at the shack end (house) and I'm
feeding the
antenna with 50 Ohm RG-58 C/U coax at the far end of the garden. If
I
can
get it working well I will replace it with some RG-213 that I have
here. I
put it back up yesterday and started experimenting again.

The End Fed at the moment has 15 feet of 300 Ohm slotted ribbon
feeder. This
is all I had left spare. One side is connected to the wire antenna
and
the
other side left, not connected. The coax is connected to the 300
Ohm
at the
bottom and the braid side is now connected to the unconnected side
of
the
300 Ohm and also to the earth ground rod.
On 80 the receive is up 2-4 S points compared with the 40m coax
Centre
Fed
Dipole. I have not had chance to get any actual reports on 80 yet.
Maybe
this weekend.

73 Andy
OK, Andy. Noted.

I don't know if you will really improve things by using the 15 foot
of
300 ohm feeder. It's a sort of a zepp, but with one side of the
feeder
earthed. I would try disconnecting the earthed ('unconnected') side
from earth / coax braid. You can either leave it floating, or
connect
it to the coax inner. It will then be approximately a quarterwave
on
20m, fed in parallel with the long wire.

Don't read too much into the excellent SWR you're getting with the
tuner. That's what the TX sees, but the tuner can't affect the SWR
on
the aerial feeder. If the coax SWR is sky high (and it can be if
the
impedance at aerial feed point is high), the coax losses will be
much
more that you would get compared with when it is matched correctly.
You only get away with it by using the lowest-loss you can find,
and
keeping the coax as short as possible.

I'm not surprised that 80m on the endfed is a bit better than the
40m
dipole. But what's 40m like on the endfed? That's when the feed
impedance (and coax SWR) will be very high, and where the RG-213
might
perform better noticeably better than the RG-58.

As I think I said before, although I am an advocate of simply using
coax (regardless), after all these years I am considering in
investing
in something like a SG230 remote tuner for the far end of the coax.
-- Ian


Ian,
I'll have to do some experimenting with the 300 Ohm feeder and see
what
happens. The End Fed on 40m is very poor indeed. I would say unusable
like it is.
The End Fed wire at the moment is resonate on 2. 682 MHz.
The funny thing is that when I cut the wire to bring the End Fed to
resonate on 80m, no matter how much wire I cut off it doesn't really
move from the 2.682 MHz. I have tried this with and with out the
ribbon
feeder being in place and with coax connected direct and the braid
connected to the earth rod.
What would cause this?
I have no problem using the Analyser with my mobile and centre fed
dipoles.
73 Andy

adding a suitably cut wire counterpoise at +% for each band should
certainly assist things .

I rather think that Andy can't add counterpoises. A decent earthing
system
should work (although additional counterpoises certainly won't do any
harm).

Re the 2.682MHz resonance, this may be because the coax is completely
mismatched at lots of frequencies, and what you're seeing this is
more-or-less a spurious resonance of the coax itself. Do you still get
it
with the wire completely disconnected? Even with centre-fed dipoles,
you
often get some very unexpected resonances way off frequency (especially
of
you are doing a wideband frequency sweep of the return loss / SWR).

As I said previously, persuading an approximate halfwave endfed (which
is
what you have on 40m) to work with a coax feed is certainly not ideal,
but
you can usually get it to work fairly well (with all the provisos
already
discussed). My setup here is almost twice the size of what you have, so
the wire feed impedance will be low on 160m and I high on 80m and 40m.
80m
(corresponding to your 40m) is certainly lively enough. On 40m, the
performance does not seem to be unduly poor compared with the signal
reports swapped between others on the band.

So, Andy, I simply don't know why your 40m is so poor. Have you tried
(temporarily) reducing the length to around 33 feet, so that it is a
quarterwave on 40m? This should give a reasonable match for your coax
(at
least, nothing you can't tune out back in the shack). If this is more
lively than the 64 feet, maybe you can try two wires in parallel. This
can
be discussed later if the 33 feet shows promise. If a multiband (and
possibly compromise) aerial doesn't work well, it's a good idea to try
something simple which you know SHOULD work. The problem may lie
elsewhere.

Finally, can I ask you to follow the standard practice of bottom
posting!
Cheers...
--
Ian

I've have just connected the Analyser at the feed point on the End fed
wire.
The frequency is now at 2.898 MHz without coax being in line. I have just
tried
to shorten the Antenna again to bring the frequency closer to the 80m
band,
but
it will not adjust from this frequency.

Ummmm...
Obviously something is wrong. It looks like your analyser is simply
telling lies. Could it have a spurious resonance at this frequency?

What's confusing me is that the End fed wire should be longer than a 1/4
wave on 80
and the frequency that it ended up on, that is now 2.898 would be
about right for the length.

A quarterwave on 80m is around 66 feet. Your 63 feet is actually a bit on
the short side. Being only 20 feet up may pull the resonance a bit lower,
but I doubt is could be anywhere as low as 2.898MHz.

So why won't that frequency change when I start
trimming the wire down in size?
It just isn't making any sense to me. The resonant frequency surely
should
change with the altered length.

If shortening the aerial doesn't change the frequency, I don't think your
analyser is measuring the aerial. This is indeed a puzzle. As I suggested
before, you could go from the sublime to the ridiculous, and try
something like 33 feet, which should resonate at around 7MHz. If it
sticks at 2.898MHz, something is seriously amiss.

--
Ian

MFJ Analyser ????

Isolate the transmission line (coax) from the antenna, ie; UGLY BALUN,
Line Isolator

analyser may have copted a nose full of RF from the braid of feedline,
with such a mismatch

should build resonant antennas first, before inserting giant matcher, just
to see how much of your RF is dissipated in the match box. TX and RX

In message , Albert
writes

"Ian Jackson" wrote in message
...
In message , Andy
writes

"Ian Jackson" wrote in message
...
In message , atec77
writes
Andy wrote:
"Ian Jackson" wrote in
message ...
In message , Andy
writes


"Ian Jackson" wrote in
message
...
Andy, is your endfed wire the one in your other thread of the 8th
June (ie
the 80 Meter End Fed, fed with coax at the far end)? If so,
presumably the
tuner is at the shack end. Or are you feeding it from the shack
end.


In message , Andy
writes

--

Hi Ian,

Yes its the same. The tuner is at the shack end (house) and I'm
feeding the
antenna with 50 Ohm RG-58 C/U coax at the far end of the garden. If
I
can
get it working well I will replace it with some RG-213 that I have
here. I
put it back up yesterday and started experimenting again.

The End Fed at the moment has 15 feet of 300 Ohm slotted ribbon
feeder. This
is all I had left spare. One side is connected to the wire antenna
and
the
other side left, not connected. The coax is connected to the 300 Ohm
at the
bottom and the braid side is now connected to the unconnected side
of
the
300 Ohm and also to the earth ground rod.
On 80 the receive is up 2-4 S points compared with the 40m coax
Centre
Fed
Dipole. I have not had chance to get any actual reports on 80 yet.
Maybe
this weekend.

73 Andy
OK, Andy. Noted.

I don't know if you will really improve things by using the 15 foot
of
300 ohm feeder. It's a sort of a zepp, but with one side of the
feeder
earthed. I would try disconnecting the earthed ('unconnected') side
from earth / coax braid. You can either leave it floating, or
connect
it to the coax inner. It will then be approximately a quarterwave on
20m, fed in parallel with the long wire.

Don't read too much into the excellent SWR you're getting with the
tuner. That's what the TX sees, but the tuner can't affect the SWR
on
the aerial feeder. If the coax SWR is sky high (and it can be if the
impedance at aerial feed point is high), the coax losses will be
much
more that you would get compared with when it is matched correctly.
You only get away with it by using the lowest-loss you can find, and
keeping the coax as short as possible.

I'm not surprised that 80m on the endfed is a bit better than the 40m
dipole. But what's 40m like on the endfed? That's when the feed
impedance (and coax SWR) will be very high, and where the RG-213
might
perform better noticeably better than the RG-58.

As I think I said before, although I am an advocate of simply using
coax (regardless), after all these years I am considering in
investing
in something like a SG230 remote tuner for the far end of the coax.
-- Ian


Ian,
I'll have to do some experimenting with the 300 Ohm feeder and see
what
happens. The End Fed on 40m is very poor indeed. I would say unusable
like it is.
The End Fed wire at the moment is resonate on 2. 682 MHz.
The funny thing is that when I cut the wire to bring the End Fed to
resonate on 80m, no matter how much wire I cut off it doesn't really
move from the 2.682 MHz. I have tried this with and with out the
ribbon
feeder being in place and with coax connected direct and the braid
connected to the earth rod.
What would cause this?
I have no problem using the Analyser with my mobile and centre fed
dipoles.
73 Andy

adding a suitably cut wire counterpoise at +% for each band should
certainly assist things .

I rather think that Andy can't add counterpoises. A decent earthing
system
should work (although additional counterpoises certainly won't do any
harm).

Re the 2.682MHz resonance, this may be because the coax is completely
mismatched at lots of frequencies, and what you're seeing this is
more-or-less a spurious resonance of the coax itself. Do you still get
it
with the wire completely disconnected? Even with centre-fed dipoles, you
often get some very unexpected resonances way off frequency (especially
of
you are doing a wideband frequency sweep of the return loss / SWR).

As I said previously, persuading an approximate halfwave endfed (which
is
what you have on 40m) to work with a coax feed is certainly not ideal,
but
you can usually get it to work fairly well (with all the provisos
already
discussed). My setup here is almost twice the size of what you have, so
the wire feed impedance will be low on 160m and I high on 80m and 40m.
80m
(corresponding to your 40m) is certainly lively enough. On 40m, the
performance does not seem to be unduly poor compared with the signal
reports swapped between others on the band.

So, Andy, I simply don't know why your 40m is so poor. Have you tried
(temporarily) reducing the length to around 33 feet, so that it is a
quarterwave on 40m? This should give a reasonable match for your coax
(at
least, nothing you can't tune out back in the shack). If this is more
lively than the 64 feet, maybe you can try two wires in parallel. This
can
be discussed later if the 33 feet shows promise. If a multiband (and
possibly compromise) aerial doesn't work well, it's a good idea to try
something simple which you know SHOULD work. The problem may lie
elsewhere.

Finally, can I ask you to follow the standard practice of bottom
posting!
Cheers...
--
Ian

I've have just connected the Analyser at the feed point on the End fed
wire.
The frequency is now at 2.898 MHz without coax being in line. I have just
tried
to shorten the Antenna again to bring the frequency closer to the 80m
band,
but
it will not adjust from this frequency.

Ummmm...
Obviously something is wrong. It looks like your analyser is simply
telling lies. Could it have a spurious resonance at this frequency?

What's confusing me is that the End fed wire should be longer than a 1/4
wave on 80
and the frequency that it ended up on, that is now 2.898 would be
about right for the length.

A quarterwave on 80m is around 66 feet. Your 63 feet is actually a bit on
the short side. Being only 20 feet up may pull the resonance a bit lower,
but I doubt is could be anywhere as low as 2.898MHz.

So why won't that frequency change when I start
trimming the wire down in size?
It just isn't making any sense to me. The resonant frequency surely should
change with the altered length.

If shortening the aerial doesn't change the frequency, I don't think your
analyser is measuring the aerial. This is indeed a puzzle. As I suggested
before, you could go from the sublime to the ridiculous, and try something
like 33 feet, which should resonate at around 7MHz. If it sticks at
2.898MHz, something is seriously amiss.

--
Ian

MFJ Analyser ????

Isolate the transmission line (coax) from the antenna, ie; UGLY BALUN, Line
Isolator

analyser may have copted a nose full of RF from the braid of feedline,
with such a mismatch

should build resonant antennas first, before inserting giant matcher, just
to see how much of your RF is dissipated in the match box. TX and RX

Unless I mis-read something, Andy says that he tried the analyser
directly on the antenna (at the antenna feedpoint) - so no coax was
involved in this particular test.

He seems to get a resonance at 2.898MHz, regardless of the length of the
antenna. Could this be because there is a strong (and permanent) RF
signal which is being picked up on the antenna, and is confusing the
analyser?
--
Ian

"Andy" wrote in message
...
I haven't had time to try a 33" End fed to see if it would tune on 40m .But
I did have time to connect a temp 60 feet of wire from the top of the
ribbon feeder on the braid side to make a close 63 feet centre fed dipole
fed with 300 Ohm feeder and the antenna resonates at 3.780 MHz with a 1.1:1
and the AT1KP backs this reading up. I haven't tried to lengthen or shorten
the antenna yet. To see if it changes resonance, but I will do tomorrow.

It can't stay like that unfortunately.

So either my Analyser doesn't like to read End Fed antennas or there
something else causing the funny readings. If the Analyser senses the
change in frequency tomorrow when I start lengthening the antenna then it
must be working OK or there is a fault with it and it can't read End Fed
wires correctly. Is this even possible considering its reading everything
else correct.

What do you think?

73 Andy


"Ian Jackson" wrote in message
...
In message , Andy
writes

"Ian Jackson" wrote in message
...
In message , atec77
writes
Andy wrote:
"Ian Jackson" wrote in
message ...
In message , Andy
writes


"Ian Jackson" wrote in
message
...
Andy, is your endfed wire the one in your other thread of the 8th
June (ie
the 80 Meter End Fed, fed with coax at the far end)? If so,
presumably the
tuner is at the shack end. Or are you feeding it from the shack
end.


In message , Andy
writes

--

Hi Ian,

Yes its the same. The tuner is at the shack end (house) and I'm
feeding the
antenna with 50 Ohm RG-58 C/U coax at the far end of the garden. If
I
can
get it working well I will replace it with some RG-213 that I have
here. I
put it back up yesterday and started experimenting again.

The End Fed at the moment has 15 feet of 300 Ohm slotted ribbon
feeder. This
is all I had left spare. One side is connected to the wire antenna
and
the
other side left, not connected. The coax is connected to the 300
Ohm
at the
bottom and the braid side is now connected to the unconnected side
of
the
300 Ohm and also to the earth ground rod.
On 80 the receive is up 2-4 S points compared with the 40m coax
Centre
Fed
Dipole. I have not had chance to get any actual reports on 80 yet.
Maybe
this weekend.

73 Andy
OK, Andy. Noted.

I don't know if you will really improve things by using the 15 foot
of
300 ohm feeder. It's a sort of a zepp, but with one side of the
feeder
earthed. I would try disconnecting the earthed ('unconnected') side
from earth / coax braid. You can either leave it floating, or
connect
it to the coax inner. It will then be approximately a quarterwave
on
20m, fed in parallel with the long wire.

Don't read too much into the excellent SWR you're getting with the
tuner. That's what the TX sees, but the tuner can't affect the SWR
on
the aerial feeder. If the coax SWR is sky high (and it can be if
the
impedance at aerial feed point is high), the coax losses will be
much
more that you would get compared with when it is matched correctly.
You only get away with it by using the lowest-loss you can find,
and
keeping the coax as short as possible.

I'm not surprised that 80m on the endfed is a bit better than the
40m
dipole. But what's 40m like on the endfed? That's when the feed
impedance (and coax SWR) will be very high, and where the RG-213
might
perform better noticeably better than the RG-58.

As I think I said before, although I am an advocate of simply using
coax (regardless), after all these years I am considering in
investing
in something like a SG230 remote tuner for the far end of the coax.
-- Ian


Ian,
I'll have to do some experimenting with the 300 Ohm feeder and see
what
happens. The End Fed on 40m is very poor indeed. I would say unusable
like it is.
The End Fed wire at the moment is resonate on 2. 682 MHz.
The funny thing is that when I cut the wire to bring the End Fed to
resonate on 80m, no matter how much wire I cut off it doesn't really
move from the 2.682 MHz. I have tried this with and with out the
ribbon
feeder being in place and with coax connected direct and the braid
connected to the earth rod.
What would cause this?
I have no problem using the Analyser with my mobile and centre fed
dipoles.
73 Andy

adding a suitably cut wire counterpoise at +% for each band should
certainly assist things .

I rather think that Andy can't add counterpoises. A decent earthing
system
should work (although additional counterpoises certainly won't do any
harm).

Re the 2.682MHz resonance, this may be because the coax is completely
mismatched at lots of frequencies, and what you're seeing this is
more-or-less a spurious resonance of the coax itself. Do you still get
it
with the wire completely disconnected? Even with centre-fed dipoles,
you
often get some very unexpected resonances way off frequency (especially
of
you are doing a wideband frequency sweep of the return loss / SWR).

As I said previously, persuading an approximate halfwave endfed (which
is
what you have on 40m) to work with a coax feed is certainly not ideal,
but
you can usually get it to work fairly well (with all the provisos
already
discussed). My setup here is almost twice the size of what you have, so
the wire feed impedance will be low on 160m and I high on 80m and 40m.
80m
(corresponding to your 40m) is certainly lively enough. On 40m, the
performance does not seem to be unduly poor compared with the signal
reports swapped between others on the band.

So, Andy, I simply don't know why your 40m is so poor. Have you tried
(temporarily) reducing the length to around 33 feet, so that it is a
quarterwave on 40m? This should give a reasonable match for your coax
(at
least, nothing you can't tune out back in the shack). If this is more
lively than the 64 feet, maybe you can try two wires in parallel. This
can
be discussed later if the 33 feet shows promise. If a multiband (and
possibly compromise) aerial doesn't work well, it's a good idea to try
something simple which you know SHOULD work. The problem may lie
elsewhere.

Finally, can I ask you to follow the standard practice of bottom
posting!
Cheers...
--
Ian

I've have just connected the Analyser at the feed point on the End fed
wire.
The frequency is now at 2.898 MHz without coax being in line. I have just
tried
to shorten the Antenna again to bring the frequency closer to the 80m
band,
but
it will not adjust from this frequency.

Ummmm...
Obviously something is wrong. It looks like your analyser is simply
telling lies. Could it have a spurious resonance at this frequency?

What's confusing me is that the End fed wire should be longer than a 1/4
wave on 80
and the frequency that it ended up on, that is now 2.898 would be
about right for the length.

A quarterwave on 80m is around 66 feet. Your 63 feet is actually a bit on
the short side. Being only 20 feet up may pull the resonance a bit lower,
but I doubt is could be anywhere as low as 2.898MHz.

So why won't that frequency change when I start
trimming the wire down in size?
It just isn't making any sense to me. The resonant frequency surely
should
change with the altered length.

If shortening the aerial doesn't change the frequency, I don't think your
analyser is measuring the aerial. This is indeed a puzzle. As I suggested
before, you could go from the sublime to the ridiculous, and try
something like 33 feet, which should resonate at around 7MHz. If it
sticks at 2.898MHz, something is seriously amiss.

--
Ian



yes tricky, have you done the ZO test on the RG-58 ? using the test gear
at the freqs you discribe, 10 turns rg-213 @ 10 " hence UGLY
less as you go up the band, or 12 x77 type ferrite beads
close proximity Stray RF, CONNECTED OR NOT and direct sunlight on the
meter face ( summer for a period of time ) are two sure ways to Kill a MFJ
analyser

In message , Andy
writes
"Ian Jackson" wrote in message
...
In message , Andy
writes

"Ian Jackson" wrote in message
...
In message , atec77
writes
Andy wrote:
"Ian Jackson" wrote in
message ...
In message , Andy
writes


"Ian Jackson" wrote in
message
...
Andy, is your endfed wire the one in your other thread of the 8th
June (ie
the 80 Meter End Fed, fed with coax at the far end)? If so,
presumably the
tuner is at the shack end. Or are you feeding it from the shack
end.


In message , Andy
writes

--

Hi Ian,

Yes its the same. The tuner is at the shack end (house) and I'm
feeding the
antenna with 50 Ohm RG-58 C/U coax at the far end of the garden. If
I
can
get it working well I will replace it with some RG-213 that I have
here. I
put it back up yesterday and started experimenting again.

The End Fed at the moment has 15 feet of 300 Ohm slotted ribbon
feeder. This
is all I had left spare. One side is connected to the wire antenna
and
the
other side left, not connected. The coax is connected to the 300 Ohm
at the
bottom and the braid side is now connected to the unconnected side
of
the
300 Ohm and also to the earth ground rod.
On 80 the receive is up 2-4 S points compared with the 40m coax
Centre
Fed
Dipole. I have not had chance to get any actual reports on 80 yet.
Maybe
this weekend.

73 Andy
OK, Andy. Noted.

I don't know if you will really improve things by using the 15 foot
of
300 ohm feeder. It's a sort of a zepp, but with one side of the
feeder
earthed. I would try disconnecting the earthed ('unconnected') side
from earth / coax braid. You can either leave it floating, or
connect
it to the coax inner. It will then be approximately a quarterwave on
20m, fed in parallel with the long wire.

Don't read too much into the excellent SWR you're getting with the
tuner. That's what the TX sees, but the tuner can't affect the SWR
on
the aerial feeder. If the coax SWR is sky high (and it can be if the
impedance at aerial feed point is high), the coax losses will be
much
more that you would get compared with when it is matched correctly.
You only get away with it by using the lowest-loss you can find, and
keeping the coax as short as possible.

I'm not surprised that 80m on the endfed is a bit better than the 40m
dipole. But what's 40m like on the endfed? That's when the feed
impedance (and coax SWR) will be very high, and where the RG-213
might
perform better noticeably better than the RG-58.

As I think I said before, although I am an advocate of simply using
coax (regardless), after all these years I am considering in
investing
in something like a SG230 remote tuner for the far end of the coax.
-- Ian


Ian,
I'll have to do some experimenting with the 300 Ohm feeder and see
what
happens. The End Fed on 40m is very poor indeed. I would say unusable
like it is.
The End Fed wire at the moment is resonate on 2. 682 MHz.
The funny thing is that when I cut the wire to bring the End Fed to
resonate on 80m, no matter how much wire I cut off it doesn't really
move from the 2.682 MHz. I have tried this with and with out the
ribbon
feeder being in place and with coax connected direct and the braid
connected to the earth rod.
What would cause this?
I have no problem using the Analyser with my mobile and centre fed
dipoles.
73 Andy

adding a suitably cut wire counterpoise at +% for each band should
certainly assist things .

I rather think that Andy can't add counterpoises. A decent earthing
system
should work (although additional counterpoises certainly won't do any
harm).

Re the 2.682MHz resonance, this may be because the coax is completely
mismatched at lots of frequencies, and what you're seeing this is
more-or-less a spurious resonance of the coax itself. Do you still get
it
with the wire completely disconnected? Even with centre-fed dipoles, you
often get some very unexpected resonances way off frequency (especially
of
you are doing a wideband frequency sweep of the return loss / SWR).

As I said previously, persuading an approximate halfwave endfed (which
is
what you have on 40m) to work with a coax feed is certainly not ideal,
but
you can usually get it to work fairly well (with all the provisos
already
discussed). My setup here is almost twice the size of what you have, so
the wire feed impedance will be low on 160m and I high on 80m and 40m.
80m
(corresponding to your 40m) is certainly lively enough. On 40m, the
performance does not seem to be unduly poor compared with the signal
reports swapped between others on the band.

So, Andy, I simply don't know why your 40m is so poor. Have you tried
(temporarily) reducing the length to around 33 feet, so that it is a
quarterwave on 40m? This should give a reasonable match for your coax
(at
least, nothing you can't tune out back in the shack). If this is more
lively than the 64 feet, maybe you can try two wires in parallel. This
can
be discussed later if the 33 feet shows promise. If a multiband (and
possibly compromise) aerial doesn't work well, it's a good idea to try
something simple which you know SHOULD work. The problem may lie
elsewhere.

Finally, can I ask you to follow the standard practice of bottom
posting!
Cheers...
--
Ian

I've have just connected the Analyser at the feed point on the End fed
wire.
The frequency is now at 2.898 MHz without coax being in line. I have just
tried
to shorten the Antenna again to bring the frequency closer to the 80m
band,
but
it will not adjust from this frequency.

Ummmm...
Obviously something is wrong. It looks like your analyser is simply
telling lies. Could it have a spurious resonance at this frequency?

What's confusing me is that the End fed wire should be longer than a 1/4
wave on 80
and the frequency that it ended up on, that is now 2.898 would be
about right for the length.

A quarterwave on 80m is around 66 feet. Your 63 feet is actually a bit on
the short side. Being only 20 feet up may pull the resonance a bit lower,
but I doubt is could be anywhere as low as 2.898MHz.

So why won't that frequency change when I start
trimming the wire down in size?
It just isn't making any sense to me. The resonant frequency surely should
change with the altered length.

If shortening the aerial doesn't change the frequency, I don't think your
analyser is measuring the aerial. This is indeed a puzzle. As I suggested
before, you could go from the sublime to the ridiculous, and try something
like 33 feet, which should resonate at around 7MHz. If it sticks at
2.898MHz, something is seriously amiss.

--
Ian

I haven't had time to try a 33" End fed to see if it would tune on 40m .But
I did have time to connect a temp 60 feet of wire from the top of the ribbon
feeder on the braid side to make a close 63 feet centre fed dipole fed with
300 Ohm feeder and the antenna resonates at 3.780 MHz with a 1.1:1 and the
AT1KP backs this reading up. I haven't tried to lengthen or shorten the
antenna yet. To see if it changes resonance, but I will do tomorrow.

It can't stay like that unfortunately.

So either my Analyser doesn't like to read End Fed antennas or there
something else causing the funny readings. If the Analyser senses the change
in frequency tomorrow when I start lengthening the antenna then it must be
working OK or there is a fault with it and it can't read End Fed wires
correctly. Is this even possible considering its reading everything else
correct.

What do you think?

73 Andy

Andy, you've gone back to top posting, and this makes it very difficult
to follow the discussion. In newsgroups (unlike emails), you should
really post at the bottom. This is the established convention.

Anyway, it's interesting what you have found out with the dipole
configuration. Presumably, you still have the coax braid and one side of
300 ohm feeder earthed. If so, I would not have expected there to be
quite such a dramatic change of resonance. However, if your earth rods
are totally ineffective (or you have disconnected the earth), you might
expect things to change a lot when you add 'the other half of the
dipole'. If you actually have room to put up an appx 60 foot + 60 foot
dipole, why not consider a G5RV (which, I believe, you have already
tried) or a W3DZZ trap dipole? This would get rid of your earthing
problems.
--
Ian