Sorry, thats SWR of around 1.7:1 at 3.7 MHz...


"Gary Smith" wrote in message
...
Hi, a friend of mine has a Yaesu RSM-2 10/80 metre antenna. He says it has
an SWR of around 3.7 MHz and wants to lower it for around 3.57 but the
adjustable tip doesnt affect it enough. Anyone got any tuning tips or
specs/instructions/comments?

Thankyou

Gary

There is absolutely nothing wrong with a VSWR of 1.7:1!!!

W1MCE

Gary Smith wrote:

Sorry, thats SWR of around 1.7:1 at 3.7 MHz...


"Gary Smith" wrote in message
...

Hi, a friend of mine has a Yaesu RSM-2 10/80 metre antenna. He says it has
an SWR of around 3.7 MHz and wants to lower it for around 3.57 but the
adjustable tip doesnt affect it enough. Anyone got any tuning tips or
specs/instructions/comments?

Thankyou

Gary

Amen and Amen! back in the early days of GPS (Then called the BRN-3 Transit
System) The transmit antennas has an SWR of 13:1. SWR meters will be
outlawed the day I take over as the world dictator.

I have never, ever, understood this preoccupation with SWR. I am guessing it
comes from the CB world where getting one's "SWR's down" was the holy
grail...
"Dave Shrader" wrote in message
news:YmEFb.426478$Dw6.1312140@attbi_s02...
There is absolutely nothing wrong with a VSWR of 1.7:1!!!

W1MCE

"w4jle" W4JLE(remove this to wrote in message
... I have never, ever, understood this
preoccupation with SWR. I am guessing it
comes from the CB world where getting one's "SWR's down" was the holy
grail...

When running low power, like CB'rs and QRP operators do, I can easily
understand the "preoccupation" with SWR. And when I used to run vacuum tube
transmitters in the USAF, SWR was important then too... high SWR levels were
not good for the finals.

Jerry
--
Jerry Bransford
To email, remove 'me' from my email address
KC6TAY, PP-ASEL
See the Geezer Jeep at
http://members.cox.net/jerrypb/

While a transmitter looking into an impedence mismatch can be a problem,
transforming the impedence the transmitter sees satisfies the transmitter
and has no effect on antenna SWR. Everybody's happy, nothing changes as far
as SWR.

An interesting exercise, compare an antenna cut so that is 1:1, change it so
that the SWR is now 3:1 and tell me what difference one would observe at the
receiving end.

You may use a tuner to match the transmitter to the newly adjusted antenna.


"Jerry Bransford" wrote in message
news:E2NFb.25033$gN.5459@fed1read05...
"w4jle" W4JLE(remove this to wrote in message
... I have never, ever, understood
this
preoccupation with SWR. I am guessing it
comes from the CB world where getting one's "SWR's down" was the holy
grail...

When running low power, like CB'rs and QRP operators do, I can easily
understand the "preoccupation" with SWR. And when I used to run vacuum
tube
transmitters in the USAF, SWR was important then too... high SWR levels
were
not good for the finals.

Jerry
--
Jerry Bransford
To email, remove 'me' from my email address
KC6TAY, PP-ASEL
See the Geezer Jeep at
http://members.cox.net/jerrypb/

"w4jle" W4JLE(remove this to wrote in message
...
While a transmitter looking into an impedence mismatch can be a problem,
transforming the impedence the transmitter sees satisfies the transmitter
and has no effect on antenna SWR. Everybody's happy, nothing changes as
far
as SWR.

Now you're changing things by adding a tuner... the net effect is that the
transmitter is now seeing a 1:1 swr. All we talked about was your claiming
there was a preoccupation with SWR... if there was no problem with a high
swr, then there's no need for the tuner you just inserted into your
justification.

There is and always will be a need to present the transmitter with the
lowest possible SWR, regardless of if it is accomplished with a well-tuned
antenna or if that is not possible, inserting an antenna tuner between the
transmitter and antenna. So you can't get away from a "preoccupation" with
SWR no matter what you like to think.

Jerry
--
Jerry Bransford
To email, remove 'me' from my email address
KC6TAY, PP-ASEL
See the Geezer Jeep at
http://members.cox.net/jerrypb/

Someone sed:

"There is and always will be a need to present the transmitter with the
lowest possible SWR,..."
--------------------------------
It's actually to present the xmtr with the proper load impedance with or
without an actual antenna connected. If no antenna is connected but instead,
say, a dummy load, there is no SWR because there is no tl.

Jack, K9CUN

"Now you're changing things by adding a tuner... the net effect is that the
transmitter is now seeing a 1:1 swr."
---------------
So the sending end impedance is the Zo of the line. What if that value is NOT
what the xmtr needs to see for a match to its output. E.g. The tl has a Zo of
398 Ohms, the SWR is 1 so the transmitter sees a load impedance is 398 Ohms.
May be bad for the xmtr that wants to work into diffrent load, say 50 Ohms or
so.

73 de Jack, K9CUN

That is pure nonsense! The tuner is only an impedence matching device. It
has NO effect on SWR.

Have you ever run mobile? Did you tune for best SWR, or best field strength?
Did they occur at the same tuning points?

If you said SWR, back to Ch 19 and co-phased antennas.



"Jerry Bransford" wrote in message
news3RFb.26455$gN.9457@fed1read05...
"w4jle" W4JLE(remove this to wrote in message
...
While a transmitter looking into an impedence mismatch can be a problem,
transforming the impedence the transmitter sees satisfies the
transmitter
and has no effect on antenna SWR. Everybody's happy, nothing changes as
far
as SWR.

Now you're changing things by adding a tuner... the net effect is that the
transmitter is now seeing a 1:1 swr. All we talked about was your
claiming
there was a preoccupation with SWR... if there was no problem with a high
swr, then there's no need for the tuner you just inserted into your
justification.

There is and always will be a need to present the transmitter with the
lowest possible SWR, regardless of if it is accomplished with a well-tuned
antenna or if that is not possible, inserting an antenna tuner between the
transmitter and antenna. So you can't get away from a "preoccupation"
with
SWR no matter what you like to think.

Jerry
--
Jerry Bransford
To email, remove 'me' from my email address
KC6TAY, PP-ASEL
See the Geezer Jeep at
http://members.cox.net/jerrypb/

"There is and always will be a need to present the transmitter with the
lowest possible SWR, regardless of if it is accomplished with a well-tuned
antenna or if that is not possible, inserting an antenna tuner between the
transmitter and antenna"

====================

Many years ago when transmitters had tuneable outputs, matching cud be achieved
by something called a "pi network" in the transmitter box.

This circuit resonated the final plate circuit and provided a match to the
sending end impedance of the tl. Granted the magnitude of the SWR, i.e.,
degree of mismatch, it wud match wasn't as much as modern day "tuners".

They are not antenna tuners. If they were they wud be located at the antenna,
not the hamshack.

73 de Jack, K9CUN