"Ham op" wrote in message
...
7.78 Db BETTER [+1 1/4 S unit] than 100 watts.

Upgrade the vertical to a beam and the net gain can be as high as +19.78
dB [3+ S units] on the path:
1] + 6 dB in receive
2] + 6 dB in transmit
3] + 7.78 dB for the amplifier.

For $1400, a beam has a much better return on investment than an
amplifier by itself.

The #1 rule I teach new or aspiring hams is "Your station efficiency,
and your enjoyment, is directly proportional to your antenna."

I will agree that it is best to go with a beter antenna, sometimes it is
just not practical. Not many can put up a beam for 80 meters and not that
many for ever 40 meters. Most amps will do 80 to 15 meters. Some will go
to 10 meters. The specs for a TH3 tribander is only 5.8 db over a dipole.
That is slightly less than 4 times the power. That is only for 20,15, 10
meters. That only takes your 100 watt rig to 400 watts. An amp that is
worth buying will put out atleast 600 to 800 watts and you can almost double
that and stay legal.

If you have to pay someone to put your beam antenna, the cost will go way
over the $ 1400.

The thing of hearing a station and he can hear you is also bogus in some
cases. I was trying to work a mobile on 80 meters that was parked running
100 watts. I could hear him just fine. About 1/4 scale on my S-meter. He
could not hear me for some local (to him) qrm and qrn. By turning on my amp
we could work each other.

The amp will not let you turn it to cut out some qrm/qrn like the beam may.

Ralph Mowery wrote:
. . .
The thing of hearing a station and he can hear you is also bogus in some
cases. I was trying to work a mobile on 80 meters that was parked running
100 watts. I could hear him just fine. About 1/4 scale on my S-meter. He
could not hear me for some local (to him) qrm and qrn. By turning on my amp
we could work each other.
. . .

The idea that if you can hear a station he can hear you is totally
wrong, especially at HF. At HF, you can have a terribly inefficient
antenna and hear people just fine. This is because the dominant noise is
coming from outside the receiver and therefore both signal and noise are
attenuated by the same amount by the loss. I can easily hear 20 meter DX
on my little Sony SW radio with a 2 foot rod antenna. But there's no
hope they'd hear me if I were transmitting with that antenna, even if
I'm running an equal or much greater amount of power than they are.

At VHF and above, where receiver noise dominates, a station you hear can
hear you if you're running about the same amount of power and if your
receivers have about the same noise figure. But this isn't at all true
at HF and below.

Roy Lewallen, W7EL

Come on Roy, your picking an example that has nothing to do with the real
world. How many people try to work 20 meters on a 2 foot Sony whip?

I failed to state the obvious. Given: Both stations are using antennas
matched to the transmitter and of a length appropriate to the band being
utilized. YaDa YaDa.

Back in the AM days, my wife heard me coming out of a skillet on the stove.
I doubt she could have talked back to me no matter how high she turned up
the heat. :)




"Roy Lewallen" wrote in message
...
The idea that if you can hear a station he can hear you is totally
wrong, especially at HF. At HF, you can have a terribly inefficient
antenna and hear people just fine. This is because the dominant noise is
coming from outside the receiver and therefore both signal and noise are
attenuated by the same amount by the loss. I can easily hear 20 meter DX
on my little Sony SW radio with a 2 foot rod antenna. But there's no
hope they'd hear me if I were transmitting with that antenna, even if
I'm running an equal or much greater amount of power than they are.

At VHF and above, where receiver noise dominates, a station you hear can
hear you if you're running about the same amount of power and if your
receivers have about the same noise figure. But this isn't at all true
at HF and below.

Roy Lewallen, W7EL

Fred W4JLE wrote:
Come on Roy, your picking an example that has nothing to do with the real
world. How many people try to work 20 meters on a 2 foot Sony whip?

Possibly the same people who want to work 80 meters on an 8 foot whip !!!!

SNIPPED

"Ham op" wrote in message
...
Fred W4JLE wrote:
Come on Roy, your picking an example that has nothing to do with the
real
world. How many people try to work 20 meters on a 2 foot Sony whip?

Possibly the same people who want to work 80 meters on an 8 foot whip !!!!

SNIPPED

It s easy to see you have no concept of how things work. An 8 foot whip is
about as big as most mobiles can use. I just worked a friend of mine that
does a lot of camping. He uses either a screwdriver antenna or a dipole
only up about 10 to 15 feet depending on where he is at. Most distances are
around 200 miles from my house. There does not seem to be much differance
in his signal with that low dipole. I am sure the dipole would be beter if
he could get it up higher, but you use what you have.

Many times the absolute strength of the signal does not make that much
differance. It is how well you can get above the noise and qrm that is on
the bands. That is where the beter antenna and higher power come in.

All of this is for the low bands , when you get to vhf and above then the
antenna system usually becomes all important.

A similar set of examples of apparent one way HF communication:
Michigan to Bangladesh in the rainy season. [much more QRN at one end than
the other]
Michigan to Antarctica in the (N.A.) Summer [heavy QRN on one end, none on
the other end]

.... and then there are the paths that have to go through the magnetic pole
....

These examples assume reasonable equipment in a rural setting.

73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Roy Lewallen" wrote in message
...


The idea that if you can hear a station he can hear you is totally
wrong, especially at HF. At HF, you can have a terribly inefficient
antenna and hear people just fine. This is because the dominant noise is
coming from outside the receiver and therefore both signal and noise are
attenuated by the same amount by the loss. I can easily hear 20 meter DX
on my little Sony SW radio with a 2 foot rod antenna. But there's no
hope they'd hear me if I were transmitting with that antenna, even if
I'm running an equal or much greater amount of power than they are.

At VHF and above, where receiver noise dominates, a station you hear can
hear you if you're running about the same amount of power and if your
receivers have about the same noise figure. But this isn't at all true
at HF and below.

Roy Lewallen, W7EL

"Ralph Mowery" bravely wrote to "All" (01 Sep 05 19:38:35)
--- on the heady topic of " Amplfier opinion"

RM From: "Ralph Mowery"
RM Xref: core-easynews rec.radio.amateur.antenna:216043


RM "Ham op" wrote in message
RM ...
7.78 Db BETTER [+1 1/4 S unit] than 100 watts.

Upgrade the vertical to a beam and the net gain can be as high as +19.78
dB [3+ S units] on the path:
1] + 6 dB in receive
2] + 6 dB in transmit
3] + 7.78 dB for the amplifier.

For $1400, a beam has a much better return on investment than an
amplifier by itself.

The #1 rule I teach new or aspiring hams is "Your station efficiency,
and your enjoyment, is directly proportional to your antenna."


RM I will agree that it is best to go with a beter antenna, sometimes it
RM is just not practical. Not many can put up a beam for 80 meters and
RM not that many for ever 40 meters. Most amps will do 80 to 15 meters.


Just wondering if it wouldn't be possible to compensate for antenna
size, by actively driving the reflective, directive elements using
correctly phased amounts of power from the xmtr output. I'm probably
preaching heresy in the midst of this bunch of laurelled gurus but I
don't mind being told I'm thinking laterally, so shoot your best
flames.

A*s*i*m*o*v

.... Firemen are proud of their hoses.