In article ,
Billy Burpelson wrote:

Telamon wrote:

So what is the voltage out the finals on a solid state transmitter?
Do you mean the DC voltage on the collectors of the output transistors
or the RF voltage into the feed line?

Telamon wrote:

Ok, Don't call the modules "finals" then but what is the output voltage
to the antenna? I would like to know what the RF current is as the
output is supposed to be 50KW.
I'm surprised a smart person like you isn't familiar with Ohm's law...

To find the RF voltage for a 50 kW transmitter, assuming a 50 ohm
transmission line:

Simple Ohm's Law:

V= the square root of (RxW) (V=volts, W=watts, R=feed line impedance in
ohms...assume 50 ohms)

To find the current:

I= the square root of (W/R)

Sometimes you're just to, too, two clueless. :-)


Telamon wrote:

You are such a retard. I was wondering what the line loss would be

Try again. You were NOT asking about the "line loss".

and I
am not familiar with the FCC rules.

Well, then could we say YOU are clueless?

The 50Kw could be the max the
transmitter puts out or the input to the antenna or it could be based on
antenna field strength measurements.

Again, could we say YOU are clueless?

And also the 50 ohms impedance would be another assumption on my part
but since a clueless wonder such as yourself generally proceeds on
unfounded assumptions you will not understand this.

You admit *YOU* know *NOTHING* about the power or impedance and yet you
accuse others of being "clueless".

Can you see the irony here? Or are you to, too, two clueless to get it?

Telamon wrote:
In article ,
"Brenda Ann" wrote:

"Telamon" wrote in
message
...

6 1/8 inch is what most radio stations use?

Pretty common for FM and TV stations.. not so much for AM. IIRC, 1520
in Portland used 3" Heliax for 50KW.

Someone wrote that 50 ohm was standard. Why am I seeing 75 ohm
components then?

Dave wrote:

75 Ohm has lower loss for long runs, but requires extra matching
sections, usually at both ends.

Sorry to rain on your parade...but to follow your own (lack of) logic:

The "extra matching sections" you talk about (at each end) would add
*more* loss than you would gain by using your -supposedly- lower loss 75
ohm cable.

Also, 75 ohm cable does not inherently have less (or more) loss than 50
ohm cable. *Loss* is dependent on the dielectric used, the materials
used and the construction (size) of the cable, no matter what the impedance.

Finally, AFAIK, 50 ohms has been traditionally used for AM/FM/SW
transmitters while 75 ohms is used for CATV distribution.

In article ,
Billy Burpelson wrote:

In article ,
Billy Burpelson wrote:

Telamon wrote:

So what is the voltage out the finals on a solid state transmitter?
Do you mean the DC voltage on the collectors of the output transistors
or the RF voltage into the feed line?

Telamon wrote:

Ok, Don't call the modules "finals" then but what is the output voltage
to the antenna? I would like to know what the RF current is as the
output is supposed to be 50KW.
I'm surprised a smart person like you isn't familiar with Ohm's law...

To find the RF voltage for a 50 kW transmitter, assuming a 50 ohm
transmission line:

Simple Ohm's Law:

V= the square root of (RxW) (V=volts, W=watts, R=feed line impedance in
ohms...assume 50 ohms)

To find the current:

I= the square root of (W/R)

Sometimes you're just to, too, two clueless. :-)


Telamon wrote:

You are such a retard. I was wondering what the line loss would be

Try again. You were NOT asking about the "line loss".

SNIP

Excuse me 'tard boy. I just happen to know what I was after here. Your
cluelessness is not my problem.

--
Telamon
Ventura, California

In article ,
Billy Burpelson wrote:

Telamon wrote:
In article ,
"Brenda Ann" wrote:

"Telamon" wrote in
message

...

6 1/8 inch is what most radio stations use?

Pretty common for FM and TV stations.. not so much for AM. IIRC, 1520
in Portland used 3" Heliax for 50KW.

Someone wrote that 50 ohm was standard. Why am I seeing 75 ohm
components then?

Dave wrote:

75 Ohm has lower loss for long runs, but requires extra matching
sections, usually at both ends.

Sorry to rain on your parade...but to follow your own (lack of) logic:

The "extra matching sections" you talk about (at each end) would add
*more* loss than you would gain by using your -supposedly- lower loss 75
ohm cable.

Also, 75 ohm cable does not inherently have less (or more) loss than 50
ohm cable. *Loss* is dependent on the dielectric used, the materials
used and the construction (size) of the cable, no matter what the impedance.

Finally, AFAIK, 50 ohms has been traditionally used for AM/FM/SW
transmitters while 75 ohms is used for CATV distribution.

I'm inclined to agree with you on this but seeing how you are clueless
99.999% of the time I'll have to think and research this a little more.

Maybe you could supply a little logic behind this view?

--
Telamon
Ventura, California

On Nov 2, 4:12*pm, Dave wrote:
Telamon wrote:

I would think that this argument would be about which would be easier
to make, use, or construct for a low loss transmission line 50 or 75
ohms.

- Argument?
-*If you want to argue about cables ad infinitum
- I suggest rec.radio.amateur.antenna

Dave D'Oh! so Political Off-Topic is OK

but something remotely related to Shortwave Radio
like technology should be taken elsewhere.

ok i get it 'not' ~ RHF

Telamon wrote:

In article ,
Dave wrote:


Telamon wrote:


I would think that this argument would be about which would be easier
to make, use, or construct for a low loss transmission line 50 or 75
ohms.


Argument?


The argument would be between you and Ian.


If you want to argue about cables ad infinitum I suggest
rec.radio.amateur.antenna


No thanks that news group blows.

As if this group doesn't? Hardly any of the valued contributors from
years past bother to post here anymore. They moved on to groups with
moderators that don't allow the kind of BS that goes on here.

RHF wrote:
On Nov 2, 4:12 pm, Dave wrote:
Telamon wrote:

I would think that this argument would be about which would be easier
to make, use, or construct for a low loss transmission line 50 or 75
ohms.
- Argument?
- If you want to argue about cables ad infinitum
- I suggest rec.radio.amateur.antenna

Dave D'Oh! so Political Off-Topic is OK

but something remotely related to Shortwave Radio
like technology should be taken elsewhere.

ok i get it 'not' ~ RHF
.

If you want to center feed a dipole, go for the 75 Ohm.

On Mon, 03 Nov 2008 16:10:01 -0500, Billy Burpelson wrote:
..

However, the thread seems clearly titled " KFI transmitter off the
air" and I doubt your statement above ( center feeding a dipole) is
implying that KFI is using a dipole.

Please 'splain.

It depends on your meaning of dipole. Read the thread all the way back,
and you'll see what I mean by bull****.

In article ,
factcheck wrote:

Telamon wrote:

In article ,
Dave wrote:


Telamon wrote:


I would think that this argument would be about which would be easier
to make, use, or construct for a low loss transmission line 50 or 75
ohms.


Argument?


The argument would be between you and Ian.


If you want to argue about cables ad infinitum I suggest
rec.radio.amateur.antenna


No thanks that news group blows.

As if this group doesn't? Hardly any of the valued contributors from
years past bother to post here anymore. They moved on to groups with
moderators that don't allow the kind of BS that goes on here.

That news group is way worse than this one. The regulars in that news
group are all like Billy Boy. I'm thankful we just have one of those
here.

--
Telamon
Ventura, California

In article ,
Billy Burpelson wrote:

Dave wrote:

If you want to center feed a dipole, go for the 75 Ohm.

As far as it goes, you are correct in that the nominal impedance of a
half-wave, center fed dipole is around 72 Ohms only at its resonant
frequency.

So yes, you would have a good match between the feed line and the
antenna, BUT...(and there is usually a but)...

...all you are doing is moving the mismatch of the 75 ohm feed line to
the back of the transceiver, as all rigs made in the last 20 years or so
have a fixed, nominal 50 Ohm input/output.

So, would you like your mismatch at the back of your transceiver or at
the antenna? In -either- case (50 or 75 ohm line), you will still have a
nominal 1.44: 1 SWR at the resonant frequency. If you are at any other
frequency than resonance, all bets are off, no matter what impedance
coax you use.

He could use a broadband UNUN at the back of the receiver Mr. Clueless.

--
Telamon
Ventura, California