On Dec 28, 7:54*pm, Telamon
wrote:
In article ,



*Dave wrote:
John Smith wrote:
wrote:

Well, sure, but what does transmitting have to do with
anything? We are not talking about transmitting.
* ...

It has EVERYTHING to do with it, it is the same communication, both
ways, simply in reverse ... like I have stated before, the exact same
laws of physics governing the antenna makes it equally acceptable to
both transmitting and receiving. *The same pattern seen in the signal
transmitted will be seen in the signal(s) received.

Your argument is the equivalent to arguing that a car designed to go
forward would not be acceptable when backing up ... simply ridiculous!

Regards,
JS
How does one transmit MW with a ferrite bar antenna?

- An MW ferrite antenna:
- Transmit antenna rating poor.
- Coffee mug warmer rating excellent.
-
- --
- Telamon
- Ventura, California

Telamon - Ah listening to the Early Morning Farm
"AG" Report on the AM Radio KMJ 580 kilo-cycles
with a Warm Mug of Coffee. - most excellent ~ RHF
KMJ 580 AM RADIO = http://www.kmj580.com/

On Dec 27, 12:57*pm, John Smith wrote:
Billy Burpelson wrote:
...
Say what?

He said he "ain't here to be a ham", so why would he want to transmit?

Well, consider me a "different type of ham." *In that, I always
construct my antennas to receive the best signal for the application at
hand, ALWAYS--transmitting is only a secondary consideration. *As, I
have never found an antenna which has been found to receive the most
efficiently fail to do so in xmit mode. *Given both xmitter and receiver
have the same input impedances ...

I do, frequently, see hams adjust the antenna, and its' type, for the
xmitter--and the best readings which can be obtained in that mode. *I
pay far more attention to how the antenna receives ... I can always
crank up power on this end, should I ever find it necessary--I don't
know what the guys capabilities on the other end is/are ...

Regards,
JS

JS,

Good Antenna Building Concept :
You Can't Talk To Them -unless-
You Can First Hear Them. ~ RHF

On Dec 28, 6:24*pm, Dave wrote:
Telamon wrote:
In article ,
*Dave wrote:

Telamon wrote:
In article ,
*Dave wrote:

RHF wrote:

Dave,

IIRC a good Amateur Radio 1/4 WL Vertical-Up-Leg
by 1/4 WL Horizontal-Out-Arm {Inverted "L" Antenna
requires very little Tuning and performs very well near
and far on the HF Band that it is 'cut' to use on.
Using a direct-connect or 1:1 UnUn at the Feed-Point
* Half-Wave Inverted "L" Antenna : 1/4 WL + 1/4 WL

Where-as the more common Shortwave Listener (SWL)
type of {Random Wire} Inverted "L" Antenna is un-equal
and usually has a shorter Vertical-Up-Leg and a longer
Horizontal-Out-Arm of at least 1V-to-2H and often
1V-to-3H or more. *Using a 9:1 Matching Transformer
and Ground Rod at the Feed-Point which is at the base
of the Vertical-Up-Leg.

"Random" implies otherwise. *Instead of a 9:1 UnUn, imagine one of these
at the feed point:

http://www.mfjenterprises.com/Produc...ductid=MFJ-927

I enjoy playing with these kind of things. *So I got a license to
transmit. *Some call that "elitist", I call it self-indulgent.

I would just call it following your interests.

Remote tuners are the right way to do things. Much better than a tuner
in the shack.

A tuner in the shack matches the radio to the transmission line. *There
is still a mismatch at the feedpoint.

Exactly. Then the transmit energy ends up heating the coax to the
antenna and components in the tuner. sarcasm on As a bonus you get RFI
in the shack. Another bonus is high voltage at points in the coax to the
antenna where you could have a flashover condition. Sarcasm off

A tuner at the antenna is a much better setup. You are doing things
right. Most HAM's don't. When Mr. Smith imagines doing this he does it
wrong.

- He's right, too. *My sloper is resonant but
- I still use a tuner to protect the transceiver.
-*I was going to use the Remote Autotuner but
- don't need it. *I get a decent match even on 160.

-IF- Your main objective is to protect the Transceiver
-then- a Tuner in the Radio-Shack will do that.
-however- If your main objective is to 'optimize' your
Transmitting Signal : Then a Tuner at the Antenna's
Feed-Point will do that better. ~ RHF

On Dec 28, 8:36*pm, Telamon
wrote:
In article ,
*John Smith wrote:

SNIP

I never even commented on where the placement of the matchbox would be,
and, as everyone knows, anywhere along the line you can place it. *The
best place would be between the coax (feedline) and the antenna-

Right. That's because you are to stupid to understand a concept until
someone rubes your nose in it. This would not even occur to you until
someone else brought it up.

-that is, taking for granted that the match from your rig to the
feedline is perfect.

SNIP

You are really worried about the match of 50 ohm *coax to your radios 50
ohm output? Now that's funny.

--
Telamon
Ventura, California

IIRC - The Characteristically 50 Ohm Impedance
Coax Cable is 'only' 50 Ohms nominal . . .
Until you attach something to it.

-IF- You attach the nominal 50 Ohm Impedance
of a Transmitter to one end of the Coax Cable the
'other' end will still be about 50 Ohms.
- - - What the Antenna will see.

However -if- You attach an Unknown "Z" Antenna
and Ground to one end of the Coax Cable then the
'other' end may will be near or far from 50 Ohms.
- - - What the Transmitter will see.

Unknown "Z" Antenna = Random Wire Antenna

as always . . . i may be 'w-r-o-n-g' - iane ~ RHF

In article ,
Dave wrote:

Telamon wrote:
In article ,
Dave wrote:

John Smith wrote:

However, in side-by-side comparisons on 10-6-2m antennas I have built,
comparing a 5/8 against the 1/2 (construction methods/materials and
matching components identical) ... the actual difference, in the real
world, must be less than the width of a meter needle in the readings ...
or, put simply, I no longer deal with the extra length required of the
5/8 ... your mileage may vary ...

The advantage of a physical height (antenna length) between 180 and 215
degrees (see previous post regarding the magic number being around 195
degrees) is improved take-off angle and reduced skywave-groundwave
interaction, not dramatic nearfield voltage increases.

Regarding Mr. Smith's comments above my experience and others is the
opposite. 5/8 is a much better performing antenna than a 1/2 wave for
local VHF and UHF communications. Well worth the effort to build a 5/8
wave antenna over a 1/2 wave. The 5/8 had some kind of series load coil
part way up the whip where the 1/2 wave match/compensation was done at
the base so the whip was solid. Sorry I can't more specific then that as
those experiments were many years ago.

Mr. Smith is still lost in space.


5/8 wavelength antennas do not require a ground plane, do they?

They need some kind of ground plane. That can be the body of a vehicle.
At a permanent site radials would be used for a raised antenna.

--
Telamon
Ventura, California

In article
,
RHF wrote:

On Dec 28, 8:36*pm, Telamon
wrote:
In article ,
*John Smith wrote:

SNIP

I never even commented on where the placement of the matchbox would be,
and, as everyone knows, anywhere along the line you can place it. *The
best place would be between the coax (feedline) and the antenna-

Right. That's because you are to stupid to understand a concept until
someone rubes your nose in it. This would not even occur to you until
someone else brought it up.

-that is, taking for granted that the match from your rig to the
feedline is perfect.

SNIP

You are really worried about the match of 50 ohm *coax to your radios 50
ohm output? Now that's funny.


IIRC - The Characteristically 50 Ohm Impedance
Coax Cable is 'only' 50 Ohms nominal . . .
Until you attach something to it.

SNIP

Nope. The cable itself has a characteristic impedance of some design
value. The spacing and size of the conductors along with the dielectric
constant of the insulator between them dictates the impedance of the
coax.

You are confusing the characteristic impedance of the coax with its
ability to be an effective transmission line. The coax only behaves as
an effective transmission line when both ends of it are terminated at
its characteristic impedance.

--
Telamon
Ventura, California

In message
,
Telamon writes
In article
,
RHF wrote:

On Dec 28, 8:36*pm, Telamon
wrote:
In article ,
*John Smith wrote:

SNIP

I never even commented on where the placement of the matchbox would be,
and, as everyone knows, anywhere along the line you can place it. *The
best place would be between the coax (feedline) and the antenna-

Right. That's because you are to stupid to understand a concept until
someone rubes your nose in it. This would not even occur to you until
someone else brought it up.

-that is, taking for granted that the match from your rig to the
feedline is perfect.

SNIP

You are really worried about the match of 50 ohm *coax to your radios 50
ohm output? Now that's funny.


IIRC - The Characteristically 50 Ohm Impedance
Coax Cable is 'only' 50 Ohms nominal . . .
Until you attach something to it.

SNIP

Nope. The cable itself has a characteristic impedance of some design
value. The spacing and size of the conductors along with the dielectric
constant of the insulator between them dictates the impedance of the
coax.

You are confusing the characteristic impedance of the coax with its
ability to be an effective transmission line. The coax only behaves as
an effective transmission line when both ends of it are terminated at
its characteristic impedance.

Are you really sure about this sweeping statement? For starters, please
define 'effective'. And are you sure that transmitter output impedances
are 50 ohms (or whatever)?
--
Ian

In article ,
Ian Jackson wrote:

In message
,
Telamon writes
In article
,
RHF wrote:

On Dec 28, 8:36*pm, Telamon
wrote:
In article ,
*John Smith wrote:

SNIP

I never even commented on where the placement of the matchbox would be,
and, as everyone knows, anywhere along the line you can place it. *The
best place would be between the coax (feedline) and the antenna-

Right. That's because you are to stupid to understand a concept until
someone rubes your nose in it. This would not even occur to you until
someone else brought it up.

-that is, taking for granted that the match from your rig to the
feedline is perfect.

SNIP

You are really worried about the match of 50 ohm *coax to your radios 50
ohm output? Now that's funny.


IIRC - The Characteristically 50 Ohm Impedance
Coax Cable is 'only' 50 Ohms nominal . . .
Until you attach something to it.

SNIP

Nope. The cable itself has a characteristic impedance of some design
value. The spacing and size of the conductors along with the dielectric
constant of the insulator between them dictates the impedance of the
coax.

You are confusing the characteristic impedance of the coax with its
ability to be an effective transmission line. The coax only behaves as
an effective transmission line when both ends of it are terminated at
its characteristic impedance.

Are you really sure about this sweeping statement?

Yes. It is basic transmission line theory. RF energy entering or leaving
a coax line has to be at the same impedance or energy is reflected. That
is a basic rule.

For starters, please define 'effective'.

The word effective was used in the context of the coax meeting its
specifications within reason.

And are you sure that transmitter output impedances are 50 ohms (or
whatever)?

If it is specified to be 50 ohms and it is not then it should find its
way back to the manufacturer for repair or redesign.

--
Telamon
Ventura, California

RHF wrote:

...
- Now that is funny. One Trolling idiot posting
- a response to another trolling idiot "don't fall
- victim to the Trolls".
-
- --
- Telamon
- Ventura, California

Ah Telamon - You know me all too well ~ RHF
.

Problem is, telemundo does not use the term "newsnet troll" correctly.

His definition: "newsnet-troll = anyone not agreeing with me or
pointing out inaccuracies in my text."

Quite obviously, most here will appear as a troll, to telemundo ... sad,
so very, very sad. :-(

Regards,
JS

In article ,
John Smith wrote:

RHF wrote:

...
- Now that is funny. One Trolling idiot posting
- a response to another trolling idiot "don't fall
- victim to the Trolls".
-

Ah Telamon - You know me all too well ~ RHF
.

Problem is, telemundo does not use the term "newsnet troll" correctly.

His definition: "newsnet-troll = anyone not agreeing with me or
pointing out inaccuracies in my text."

That is just a comprehension impaired interpretation.

Quite obviously, most here will appear as a troll, to telemundo ... sad,
so very, very sad. :-(


You have a great imagination but you don't know how to usefully apply it.

--
Telamon
Ventura, California