Ed Cregger wrote:
Instead of drilling a hole through the cinder blocks of my basement wall
(finished), I made up a barrier insert from a piece of 2x4" lumber to fit
under the lip of my window.

MFJ offers six window-mounted feed through panels for such.
Their numbers are 4600-4605. MFJ-4600 has four balanced
and two coaxial feed-throughs.

Oh, I haven't seen a 4:1 balun that is worth what it costs to ship to your
door that sells for less than $139. I've gone through three brands lately.

If one doesn't know what magnitude of impedance is
being encountered by the balun, the best balun
solution is a husky 1:1 current (choke) balun, not
a 4:1 voltage balun which is designed to deal with
200 ohms, not 2000+j2000 ohms.
--
73, Cecil http://www.w5dxp.com

"James barrett" wrote in message
...
I've read some Q&A about ladder line and I didn't see exactly my
question. I want to run 450 ohm ladder line into the house. my tuner
has a built-in balun for a ladder line so I think I can just run the
ladder line all the way to the tuner.

How do I physically attach the ladder line to the house? All I can
think of is to nail it right through the spacers onto the side of the
house. But I don't know if the nails will interfere with transmission
at all.

A second that comes to mind when considering this setup: if I run the
ladder line all the way to the tuner, how do I ground it?


Thanks,
kb1odg

I have thought of running ladder line through the wood above the
basement wall, and accross the joists above a suspended ceiling.
My main concerns a the very high field intesity on the plane of
the transmission line, and the high voltage present when using a
short dipole. For example with 100 W in; a 100 ft dipole, 55 ft
of transmission line on 1.9 MHz shows: 400 V/m (peak) only 6"
from each side of the ladder line, and a peak input voltage of
2.4 kV.

While the above is an extreme example I think some analysis
needs to be done before attempting such an instalation. With
all the satellite coax, and house wiring in the ceiling I wondered
how much TVI I would get. On 40 m I estimate about 8 V/m
(peak) from the antenna (1Kw out) at the TV. It is enough to
get into the remote control circuitry, and turn on the TV menu
blocking out the picture.

73,

Frank

Frank,
The 'simple' answer? Keep away from 'stuff' it may interfere with.
As for the worst case thing with high voltage? Change your antenna
arrangement.
How about hanging that ladder line from the suspended ceiling? Out of
the typical 'foot traffic zones'? Anyone asks, tell'em it's an RF
railroad line to your antenna. Sound crazy? so what, 'they' think
we're crazy anyway...
- 'Doc

Bob Miller wrote:


I've had good luck bringing 450-ohm line through the window using
MFJ's 4602 window feed through board. It has ceramic feed through
insulators for the balanced line, more feedthrough's for a random
wire, three coax lines and a ground wire. Even includes weather
stripping and a burgler bar.

Bob
k5qwg
That's through a window, not through a wall. I use the MFJ myself.

If I did want to use non-resonant antennas I would locate a tuner at the
antenna feedpoint, not at the generator (transmitter).

"Dave" wrote in message
m...
Bob Miller wrote:


I've had good luck bringing 450-ohm line through the window using
MFJ's 4602 window feed through board. It has ceramic feed through
insulators for the balanced line, more feedthrough's for a random
wire, three coax lines and a ground wire. Even includes weather
stripping and a burgler bar.

Bob
k5qwg
That's through a window, not through a wall. I use the MFJ myself.

If I did want to use non-resonant antennas I would locate a tuner at the
antenna feedpoint, not at the generator (transmitter).


Then you would cheat yourself of a fair amount of propagation and some of
the lower and higher frequencies available with such a set up.

You're not going to keep RF out of the shack, regardless of which system you
use. You might be able to keep some of the hot spots outside, but often
times they are close enough to the station that it is really a waste of
time.

This fascination with resonance is a leftover from CB thinking. How many
warships utilize resonant antennas? Yet they communicate the world over.

The aversion to transmatches is a ham cultural trait that has no basis in
reality, just as the CB'ers are hooked on resonant 50 ohm antennas. It's a
characteristic of the culture(s) of both types of operators, with no basis
in practical operating engineering.

Ed, N2ECW

Ed Cregger wrote:
You're not going to keep RF out of the shack, regardless of which system you
use.

My no-tuner HF antenna system at: http://www.w5dxp.com/notuner.htm
has negligible measured RF-in-the-shack even though the antenna is
a non-resonant length on most HF bands.
--
73, Cecil http://www.w5dxp.com

On Thu, 8 Jan 2009 08:50:33 -0500, "Ed Cregger"
wrote:


"Dave" wrote in message
om...
Bob Miller wrote:


I've had good luck bringing 450-ohm line through the window using
MFJ's 4602 window feed through board. It has ceramic feed through
insulators for the balanced line, more feedthrough's for a random
wire, three coax lines and a ground wire. Even includes weather
stripping and a burgler bar.

Bob
k5qwg
That's through a window, not through a wall. I use the MFJ myself.

If I did want to use non-resonant antennas I would locate a tuner at the
antenna feedpoint, not at the generator (transmitter).


Then you would cheat yourself of a fair amount of propagation and some of
the lower and higher frequencies available with such a set up.

You're not going to keep RF out of the shack, regardless of which system you
use.

FYI my 80 meter dipole with ladder line all way to the indoor tuner
does not emit RFI in the shack that I can notice, even when put into
all band use.

bob
k5qwg

You might be able to keep some of the hot spots outside, but often
times they are close enough to the station that it is really a waste of
time.

This fascination with resonance is a leftover from CB thinking. How many
warships utilize resonant antennas? Yet they communicate the world over.

The aversion to transmatches is a ham cultural trait that has no basis in
reality, just as the CB'ers are hooked on resonant 50 ohm antennas. It's a
characteristic of the culture(s) of both types of operators, with no basis
in practical operating engineering.

Ed, N2ECW

On Jan 8, 7:50*am, "Ed Cregger" wrote:


The aversion to transmatches is a ham cultural trait that has no basis in
reality, just as the CB'ers are hooked on resonant 50 ohm antennas. It's a
characteristic of the culture(s) of both types of operators, with no basis
in practical operating engineering.

Ed, N2ECW

I wouldn't say that. As an example, I've done tests showing that no
matter how careful I am with the tuner, it's settings, decent open
wire feeder, etc, I could never quite equal the performance of a coax
fed
dipole when feeding the same antenna using the tuner and ladder line.
Quite close granted, and to many people a non issue, but there *was*
a difference. Of course, the coax fed dipoles I use would generally
be considered a single band antenna. But that's no problem here.
But if I have my way, I avoid tuners if possible. I'm trading the
ability of fairly efficient multi band use, for the slightly more
efficient
coax fed single band antenna. I want to radiate every drop of RF I
can.
Also the settings of the tuner are fairly critical for the most
efficient
use. I have a 989c also, and I have done extensive testing with it
using various settings vs efficiency.
I found with the usual T network tuner such as the 989c, you might
be able to tune a load with 25 or more settings. But only the setting
using the least inductance will be fairly low loss. All of the
settings
that use more inductance than required show more tuner loss.
Up to about 20% of your power is lost in a worst case scenario.
So that is another issue. Small, being as one can make sure to
use the least inductance, but it's just another thing to fuss with
when changing bands.
Myself, I prefer to use multiple element antenna elements to
provide multi band capability. The system efficiency is very high,
and I don't have to do anything when I change bands.
It's not using a resonant antenna that makes it very efficient.
It's the ability to use the 50 ohm radio to a low loss 50 ohm
feed line, straight to the appx 50 ohm antenna without any
semi lossy mickey mouse stuff in between. :/
Now if I were required to use only one wire for all bands, I
wouldn't have any problems using ladder line and the tuner
to feed a single dipole. It will work quite well, and being I don't
have the coax fed to compare to, no one will notice the
difference.
But I bet they would notice a slight difference if I did have
both to compare to. The reason I know this is because I
have tried it. "75m" I could see the difference on receive, no
real need to compare on air reports.
But I did anyway, and as expected, they saw about the
same difference between the two systems.
When comparing the ladder line and tuner system vs the
coax system, if I had a signal that was 40 db over S9
on the tuner system, it would bump up to about 45 db over
S9 with the coax feed.
For me to see that large a difference on receive, the tuner
loss can not be considered to be just an illusion or not
based in reality.
I have no problems with anyone else using one, but I think
it's a stretch to say that anyone that prefers to avoid one
is trying to emulate a CB'er.. :/

The 'simple' answer? Keep away from 'stuff' it may interfere with.
As for the worst case thing with high voltage? Change your antenna
arrangement.
How about hanging that ladder line from the suspended ceiling? Out of
the typical 'foot traffic zones'? Anyone asks, tell'em it's an RF
railroad line to your antenna. Sound crazy? so what, 'they' think
we're crazy anyway...
- 'Doc

Most of the wiring in the ceiling is what I put there. I just wanted to
demonstrate some of the problems associated with such an instalation.
Passing high voltage lines through wood -- even with a ceramic
sleeve -- is what really bothered me. The fact is I have room for
a 200 ft dipole, but on 160 m there are still high voltages on the
transmission line. I have pretty much made up my mind to build
a remote tuner, but the parts are very expensive.

Frank

wrote:
On Jan 8, 7:50 am, "Ed Cregger" wrote:

The aversion to transmatches is a ham cultural trait that has no basis in
reality, just as the CB'ers are hooked on resonant 50 ohm antennas. It's a
characteristic of the culture(s) of both types of operators, with no basis
in practical operating engineering.

Ed, N2ECW

I wouldn't say that. As an example, I've done tests showing that no
matter how careful I am with the tuner, it's settings, decent open
wire feeder, etc, I could never quite equal the performance of a coax
fed
dipole when feeding the same antenna using the tuner and ladder line.
Quite close granted, and to many people a non issue, but there *was*
a difference. Of course, the coax fed dipoles I use would generally
be considered a single band antenna. But that's no problem here.
But if I have my way, I avoid tuners if possible. I'm trading the
ability of fairly efficient multi band use, for the slightly more
efficient
coax fed single band antenna. I want to radiate every drop of RF I
can.

There are actually a couple of different consequences to using a
non-resonant antenna, and they're often confused or lumped together. The
first is the potential for tuner loss. In many, but not all cases, it
can be made negligible -- after all, 25% power loss is only a little
more than 1 dB. But of course no argument can be made against someone
who considers "every drop" -- even a fraction of a dB -- important. The
rest of us can usually use a tuner without any perceptible reduction in
signal strength. We do need to keep in mind, however, that there are
cases where tuner efficiency can be truly bad, and avoid them when possible.

But amateurs tend to use multiband antennas without any thought at all
to radiation pattern. When the frequency gets considerably higher than a
dipole's resonant frequency, the pattern changes. So there's a good
chance that the pattern will have nulls in at least some directions
where you might want to communicate. In those cases, the difference
between a half wavelength dipole and much longer dipole can be striking.
People who don't understand the reason for the difference often
mistakenly attribute it to a change in efficiency rather than pattern.

Also the settings of the tuner are fairly critical for the most
efficient
use. I have a 989c also, and I have done extensive testing with it
using various settings vs efficiency.
I found with the usual T network tuner such as the 989c, you might
be able to tune a load with 25 or more settings. But only the setting
using the least inductance will be fairly low loss. All of the
settings
that use more inductance than required show more tuner loss.
Up to about 20% of your power is lost in a worst case scenario.
So that is another issue. Small, being as one can make sure to
use the least inductance, but it's just another thing to fuss with
when changing bands.
It's relatively easy to measure tuner efficiency when it's working into
a nice resistive load. But I'm curious about how you measured the power
the tuner was delivering to a more realistic non-resonant load
impedance. The only way I can think of to do it with any semblance of
accuracy is to connect two identical tuners back-to-back and measure the
power out of the combination. Is that how you did it? If not, how?

. . .

Roy Lewallen, W7EL