Re: [Elecraft] KX3 and its "TUNE" selection. (With mag loop)

2022-08-24 Thread jerry

On 2022-08-24 16:19, Fred Jensen wrote:

Tuning on most mag loops is very touchy, and more so on lower
frequencies, because of the extremely high Q.  My Alexloop has a
reduction gearbox on the capacitor,


*** What kind of motor does it have?  I've been planning to use a
stepper, controlled by a microcontroller.  Use frequency data from
the radio ( or at least band data ) to get it into the ballpark, and
then zero in onto resonance.

  It's not going to be a portable system.  The size of the capacitor 
alone
guarantees that.  I'm going to either mount it on a mast, or on top of a 
shed.


   - Jerry, KF6VB




 and I wish it had 3 times the

reduction it has.  I doubt you could get close enough with a
motor-driven cap to a preset position. And, exact resonance matters.
However, it's pretty easy these days to use a V-I sensor and a phase
detector to determine where resonance exactly is, and have a little
microcontroller drive the cap to zero phase difference. We used to do
it with HF mobiles.  Still may be done.

Most of the cost in transmitting loops >QRP is in the vacuum variable
capacitor, the construction to minimize I-squared R losses, and to
withstand the extremely high voltages which, at 100+ watts can range
well above 100 amps circulating current and multi-KV potentials.

73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

Geoffrey Feldman wrote on 8/24/2022 12:11 PM:
Magloops with effective remote tuning are very pricey but those are 
not (as far as I know) automatic tuning, just remote)  With a tiny bit 
of practice, it’s not hard to do manually.  I give it almost no 
thought.   To simply have a mag loop go to the perfect spot of 
resonance in response to instructions from the radio would be 
difficult if not impractical.


  The key thing here is that it’s not a problem (for low power) to 
have the mag loop close to you nor is it hard to adjust it (as I 
described) to be perfectly resonant to the radio.


  However, Julia is right.  You can have the KX3 report its frequency 
(and everything else) through the ACC1 port.  Similarly the KX3 can be 
controlled by this magic box (to transmit a bit)   Getting a mag loop 
with its very high Q to perfectly tune to that frequency would be 
interesting.  When you see how tiny the changes to the Variable Cap 
are – you might perceive the problem.   Are there effective 
auto-tuning magloops that work as perfectly as hand tuning for low 
power levels?  I’d like to know.


  I also think that complexity can get in the way of portability. The 
beauty of the mag loop I have (alex loop) is that it’s light weight, 
quick to set up and take down.  Adding complexity would change all 
that.  At that point, I would use the kxpa100 with its tuner. 
(possibly even cheaper)


  W1GCF

Geoff

  From: Julia Tuttle [mailto:ju...@juliatuttle.net]
Sent: Wednesday, August 24, 2022 12:53 PM
To: jerry
Cc: Geoffrey Feldman; Elecraft; JEROME SODUS
Subject: Re: [Elecraft] KX3 and its "TUNE" selection. (With mag loop)

  Hi Jerry,

  That's absolutely possible over the serial port (ACC1)! The 
Programmer's Reference has the details:


  https://ftp.elecraft.com/K3S/Manuals%20Downloads/K3S  
<https://ftp.elecraft.com/K3S/Manuals%20Downloads/K3S&K3&KX3&KX2%20Pgmrs%20Ref,%20G5.pdf> 
 &K3&KX3&KX2%20Pgmrs%20Ref,%20G5.pdf


  73,

  Julie

  On Wed, Aug 24, 2022, 12:49 jerry  wrote:

I'm starting work on a magloop project.  I wonder how hard it would be
to
have a transceiver tell the magloop what frequency it's tuned to?  
That

could
operationally be simpler than having to hit it with low-power RF so it
can tune
itself...

 - Jerry, KF6VB



On 2022-08-23 14:28, Geoffrey Feldman wrote:

If your antenna is a magloop - DO NOT USE the tune button. In fact,
clear
the tuner memory for your band per instructions.   The tuner feature
(assuming you have the option) is great with other antennas, 
especially
random wire but it doesn't go well with mag loops.  The xmit button 
is

simply "PTT".



For any mag loop, choose a frequency you wish to start work, 
somewhere

in
the middle of the band.  Mag Loops are high Q antennas, that is they
are
effective in a very narrow range of frequencies to which they are
adjusted
with the tuning box.  This fact should inform your thoughts on
effective
use.

Turn the tuning dial (ON THE MAG LOOP) until you hear the maximum
amount of
noise (or blessed with a real signal).   The antenna and the radio 
are

now
tuned.

Turn the KX3 tuning knob SLOWLY until you hear some kind of 
interesting

signal.  (PX3 is great for this too).

Tweak the tuning knob on the mag loop to get the strongest signal for
your
exact frequency. (just a tweak).   This is important even if you hear
the
signal, to get the most efficient use of transmitter.

If while seeking a station you hear a lot less static, adjust the mag
loop
as above.



IF s

Re: [Elecraft] KX3 and its "TUNE" selection. (With mag loop)

2022-08-24 Thread Fred Jensen
Tuning on most mag loops is very touchy, and more so on lower 
frequencies, because of the extremely high Q.  My Alexloop has a 
reduction gearbox on the capacitor, and I wish it had 3 times the 
reduction it has.  I doubt you could get close enough with a 
motor-driven cap to a preset position. And, exact resonance matters. 
However, it's pretty easy these days to use a V-I sensor and a phase 
detector to determine where resonance exactly is, and have a little 
microcontroller drive the cap to zero phase difference. We used to do it 
with HF mobiles.  Still may be done.


Most of the cost in transmitting loops >QRP is in the vacuum variable 
capacitor, the construction to minimize I-squared R losses, and to 
withstand the extremely high voltages which, at 100+ watts can range 
well above 100 amps circulating current and multi-KV potentials.


73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

Geoffrey Feldman wrote on 8/24/2022 12:11 PM:

Magloops with effective remote tuning are very pricey but those are not (as far 
as I know) automatic tuning, just remote)  With a tiny bit of practice, it’s 
not hard to do manually.  I give it almost no thought.   To simply have a mag 
loop go to the perfect spot of resonance in response to instructions from the 
radio would be difficult if not impractical.

  


The key thing here is that it’s not a problem (for low power) to have the mag 
loop close to you nor is it hard to adjust it (as I described) to be perfectly 
resonant to the radio.

  


However, Julia is right.  You can have the KX3 report its frequency (and 
everything else) through the ACC1 port.  Similarly the KX3 can be controlled by 
this magic box (to transmit a bit)   Getting a mag loop with its very high Q to 
perfectly tune to that frequency would be interesting.  When you see how tiny 
the changes to the Variable Cap are – you might perceive the problem.   Are 
there effective auto-tuning magloops that work as perfectly as hand tuning for 
low power levels?  I’d like to know.

  


I also think that complexity can get in the way of portability. The beauty of 
the mag loop I have (alex loop) is that it’s light weight, quick to set up and 
take down.  Adding complexity would change all that.  At that point, I would 
use the kxpa100 with its tuner. (possibly even cheaper)

  


W1GCF

Geoff

  


From: Julia Tuttle [mailto:ju...@juliatuttle.net]
Sent: Wednesday, August 24, 2022 12:53 PM
To: jerry
Cc: Geoffrey Feldman; Elecraft; JEROME SODUS
Subject: Re: [Elecraft] KX3 and its "TUNE" selection. (With mag loop)

  


Hi Jerry,

  


That's absolutely possible over the serial port (ACC1)! The Programmer's 
Reference has the details:

  


https://ftp.elecraft.com/K3S/Manuals%20Downloads/K3S  
<https://ftp.elecraft.com/K3S/Manuals%20Downloads/K3S&K3&KX3&KX2%20Pgmrs%20Ref,%20G5.pdf>  
&K3&KX3&KX2%20Pgmrs%20Ref,%20G5.pdf

  


73,

  


Julie

  


On Wed, Aug 24, 2022, 12:49 jerry  wrote:

I'm starting work on a magloop project.  I wonder how hard it would be
to
have a transceiver tell the magloop what frequency it's tuned to?  That
could
operationally be simpler than having to hit it with low-power RF so it
can tune
itself...

 - Jerry, KF6VB



On 2022-08-23 14:28, Geoffrey Feldman wrote:

If your antenna is a magloop - DO NOT USE the tune button. In fact,
clear
the tuner memory for your band per instructions.   The tuner feature
(assuming you have the option) is great with other antennas, especially
random wire but it doesn't go well with mag loops.  The xmit button is
simply "PTT".



For any mag loop, choose a frequency you wish to start work, somewhere
in
the middle of the band.  Mag Loops are high Q antennas, that is they
are
effective in a very narrow range of frequencies to which they are
adjusted
with the tuning box.  This fact should inform your thoughts on
effective
use.

Turn the tuning dial (ON THE MAG LOOP) until you hear the maximum
amount of
noise (or blessed with a real signal).   The antenna and the radio are
now
tuned.

Turn the KX3 tuning knob SLOWLY until you hear some kind of interesting
signal.  (PX3 is great for this too).

Tweak the tuning knob on the mag loop to get the strongest signal for
your
exact frequency. (just a tweak).   This is important even if you hear
the
signal, to get the most efficient use of transmitter.

If while seeking a station you hear a lot less static, adjust the mag
loop
as above.



IF seeking up and down the band, just rinse and repeat as above until
you
get a station to work.



Once the mag loop is tuned to the band, you won't have to adjust it
much to
tune it for the particular part of the band you are on. Gentle tweaks
is the
way.  Notice too, mag loops are very directional. Consult the
manufacturing
manual for where it's sensitive and turn it along a great circle to
where
you want to go.  (In Boston, where I live, Eur

Re: [Elecraft] KX3 and its "TUNE" selection. (With mag loop)

2022-08-24 Thread Geoffrey Feldman
Magloops with effective remote tuning are very pricey but those are not (as far 
as I know) automatic tuning, just remote)  With a tiny bit of practice, it’s 
not hard to do manually.  I give it almost no thought.   To simply have a mag 
loop go to the perfect spot of resonance in response to instructions from the 
radio would be difficult if not impractical.

 

The key thing here is that it’s not a problem (for low power) to have the mag 
loop close to you nor is it hard to adjust it (as I described) to be perfectly 
resonant to the radio.

 

However, Julia is right.  You can have the KX3 report its frequency (and 
everything else) through the ACC1 port.  Similarly the KX3 can be controlled by 
this magic box (to transmit a bit)   Getting a mag loop with its very high Q to 
perfectly tune to that frequency would be interesting.  When you see how tiny 
the changes to the Variable Cap are – you might perceive the problem.   Are 
there effective auto-tuning magloops that work as perfectly as hand tuning for 
low power levels?  I’d like to know.

 

I also think that complexity can get in the way of portability. The beauty of 
the mag loop I have (alex loop) is that it’s light weight, quick to set up and 
take down.  Adding complexity would change all that.  At that point, I would 
use the kxpa100 with its tuner. (possibly even cheaper)

 

W1GCF

Geoff

 

From: Julia Tuttle [mailto:ju...@juliatuttle.net] 
Sent: Wednesday, August 24, 2022 12:53 PM
To: jerry
Cc: Geoffrey Feldman; Elecraft; JEROME SODUS
Subject: Re: [Elecraft] KX3 and its "TUNE" selection. (With mag loop)

 

Hi Jerry,

 

That's absolutely possible over the serial port (ACC1)! The Programmer's 
Reference has the details:

 

https://ftp.elecraft.com/K3S/Manuals%20Downloads/K3S 
<https://ftp.elecraft.com/K3S/Manuals%20Downloads/K3S&K3&KX3&KX2%20Pgmrs%20Ref,%20G5.pdf>
 &K3&KX3&KX2%20Pgmrs%20Ref,%20G5.pdf

 

73,

 

Julie

 

On Wed, Aug 24, 2022, 12:49 jerry  wrote:

I'm starting work on a magloop project.  I wonder how hard it would be 
to
have a transceiver tell the magloop what frequency it's tuned to?  That 
could
operationally be simpler than having to hit it with low-power RF so it 
can tune
itself...

- Jerry, KF6VB



On 2022-08-23 14:28, Geoffrey Feldman wrote:
> If your antenna is a magloop - DO NOT USE the tune button. In fact, 
> clear
> the tuner memory for your band per instructions.   The tuner feature
> (assuming you have the option) is great with other antennas, especially
> random wire but it doesn't go well with mag loops.  The xmit button is
> simply "PTT".
> 
> 
> 
> For any mag loop, choose a frequency you wish to start work, somewhere 
> in
> the middle of the band.  Mag Loops are high Q antennas, that is they 
> are
> effective in a very narrow range of frequencies to which they are 
> adjusted
> with the tuning box.  This fact should inform your thoughts on 
> effective
> use.
> 
> Turn the tuning dial (ON THE MAG LOOP) until you hear the maximum 
> amount of
> noise (or blessed with a real signal).   The antenna and the radio are 
> now
> tuned.
> 
> Turn the KX3 tuning knob SLOWLY until you hear some kind of interesting
> signal.  (PX3 is great for this too).
> 
> Tweak the tuning knob on the mag loop to get the strongest signal for 
> your
> exact frequency. (just a tweak).   This is important even if you hear 
> the
> signal, to get the most efficient use of transmitter.
> 
> If while seeking a station you hear a lot less static, adjust the mag 
> loop
> as above.
> 
> 
> 
> IF seeking up and down the band, just rinse and repeat as above until 
> you
> get a station to work.
> 
> 
> 
> Once the mag loop is tuned to the band, you won't have to adjust it 
> much to
> tune it for the particular part of the band you are on. Gentle tweaks 
> is the
> way.  Notice too, mag loops are very directional. Consult the 
> manufacturing
> manual for where it's sensitive and turn it along a great circle to 
> where
> you want to go.  (In Boston, where I live, Europe is north east by 
> great
> circle.
> 
> 
> 
> I note there is something about tuning the radio in some mag loop
> instructions.  I find this not necessary with the KX3.  What I describe 
> here
> is what I do and it works well.
> 
> 
> 
> I have contacted Europe USB with a KX3 at 15 watts and a mag loop.  The
> antenna was on the top floor of my wood frame town house for this, not 
> even
> outdoors.  If you think about what I wrote, you want the antenna in 
> arm's
> length while working the radio.  Don't worry about your body affecting 
> the
> near field. Mag Loops are not like that.
> 
> 
> 
> -73-
> 
&g

Re: [Elecraft] KX3 and its "TUNE" selection. (With mag loop)

2022-08-24 Thread Julia Tuttle
Hi Jerry,

That's absolutely possible over the serial port (ACC1)! The Programmer's
Reference has the details:

https://ftp.elecraft.com/K3S/Manuals%20Downloads/K3S&K3&KX3&KX2%20Pgmrs%20Ref,%20G5.pdf

73,

Julie

On Wed, Aug 24, 2022, 12:49 jerry  wrote:

> I'm starting work on a magloop project.  I wonder how hard it would be
> to
> have a transceiver tell the magloop what frequency it's tuned to?  That
> could
> operationally be simpler than having to hit it with low-power RF so it
> can tune
> itself...
>
> - Jerry, KF6VB
>
>
>
> On 2022-08-23 14:28, Geoffrey Feldman wrote:
> > If your antenna is a magloop - DO NOT USE the tune button. In fact,
> > clear
> > the tuner memory for your band per instructions.   The tuner feature
> > (assuming you have the option) is great with other antennas, especially
> > random wire but it doesn't go well with mag loops.  The xmit button is
> > simply "PTT".
> >
> >
> >
> > For any mag loop, choose a frequency you wish to start work, somewhere
> > in
> > the middle of the band.  Mag Loops are high Q antennas, that is they
> > are
> > effective in a very narrow range of frequencies to which they are
> > adjusted
> > with the tuning box.  This fact should inform your thoughts on
> > effective
> > use.
> >
> > Turn the tuning dial (ON THE MAG LOOP) until you hear the maximum
> > amount of
> > noise (or blessed with a real signal).   The antenna and the radio are
> > now
> > tuned.
> >
> > Turn the KX3 tuning knob SLOWLY until you hear some kind of interesting
> > signal.  (PX3 is great for this too).
> >
> > Tweak the tuning knob on the mag loop to get the strongest signal for
> > your
> > exact frequency. (just a tweak).   This is important even if you hear
> > the
> > signal, to get the most efficient use of transmitter.
> >
> > If while seeking a station you hear a lot less static, adjust the mag
> > loop
> > as above.
> >
> >
> >
> > IF seeking up and down the band, just rinse and repeat as above until
> > you
> > get a station to work.
> >
> >
> >
> > Once the mag loop is tuned to the band, you won't have to adjust it
> > much to
> > tune it for the particular part of the band you are on. Gentle tweaks
> > is the
> > way.  Notice too, mag loops are very directional. Consult the
> > manufacturing
> > manual for where it's sensitive and turn it along a great circle to
> > where
> > you want to go.  (In Boston, where I live, Europe is north east by
> > great
> > circle.
> >
> >
> >
> > I note there is something about tuning the radio in some mag loop
> > instructions.  I find this not necessary with the KX3.  What I describe
> > here
> > is what I do and it works well.
> >
> >
> >
> > I have contacted Europe USB with a KX3 at 15 watts and a mag loop.  The
> > antenna was on the top floor of my wood frame town house for this, not
> > even
> > outdoors.  If you think about what I wrote, you want the antenna in
> > arm's
> > length while working the radio.  Don't worry about your body affecting
> > the
> > near field. Mag Loops are not like that.
> >
> >
> >
> > -73-
> >
> > W1GCF
> >
> > Geoff
> >
> > __
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:Elecraft@mailman.qth.net
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> > Message delivered to je...@tr2.com
> __
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft@mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to ju...@juliatuttle.net
>
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com 


Re: [Elecraft] KX3 and its "TUNE" selection. (With mag loop)

2022-08-24 Thread jerry
I'm starting work on a magloop project.  I wonder how hard it would be 
to
have a transceiver tell the magloop what frequency it's tuned to?  That 
could
operationally be simpler than having to hit it with low-power RF so it 
can tune

itself...

   - Jerry, KF6VB



On 2022-08-23 14:28, Geoffrey Feldman wrote:
If your antenna is a magloop - DO NOT USE the tune button. In fact, 
clear

the tuner memory for your band per instructions.   The tuner feature
(assuming you have the option) is great with other antennas, especially
random wire but it doesn't go well with mag loops.  The xmit button is
simply "PTT".



For any mag loop, choose a frequency you wish to start work, somewhere 
in
the middle of the band.  Mag Loops are high Q antennas, that is they 
are
effective in a very narrow range of frequencies to which they are 
adjusted
with the tuning box.  This fact should inform your thoughts on 
effective

use.

Turn the tuning dial (ON THE MAG LOOP) until you hear the maximum 
amount of
noise (or blessed with a real signal).   The antenna and the radio are 
now

tuned.

Turn the KX3 tuning knob SLOWLY until you hear some kind of interesting
signal.  (PX3 is great for this too).

Tweak the tuning knob on the mag loop to get the strongest signal for 
your
exact frequency. (just a tweak).   This is important even if you hear 
the

signal, to get the most efficient use of transmitter.

If while seeking a station you hear a lot less static, adjust the mag 
loop

as above.



IF seeking up and down the band, just rinse and repeat as above until 
you

get a station to work.



Once the mag loop is tuned to the band, you won't have to adjust it 
much to
tune it for the particular part of the band you are on. Gentle tweaks 
is the
way.  Notice too, mag loops are very directional. Consult the 
manufacturing
manual for where it's sensitive and turn it along a great circle to 
where
you want to go.  (In Boston, where I live, Europe is north east by 
great

circle.



I note there is something about tuning the radio in some mag loop
instructions.  I find this not necessary with the KX3.  What I describe 
here

is what I do and it works well.



I have contacted Europe USB with a KX3 at 15 watts and a mag loop.  The
antenna was on the top floor of my wood frame town house for this, not 
even
outdoors.  If you think about what I wrote, you want the antenna in 
arm's
length while working the radio.  Don't worry about your body affecting 
the

near field. Mag Loops are not like that.



-73-

W1GCF

Geoff

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to je...@tr2.com

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com 


[Elecraft] KX3 and its "TUNE" selection. (With mag loop)

2022-08-23 Thread Geoffrey Feldman
If your antenna is a magloop - DO NOT USE the tune button. In fact, clear
the tuner memory for your band per instructions.   The tuner feature
(assuming you have the option) is great with other antennas, especially
random wire but it doesn't go well with mag loops.  The xmit button is
simply "PTT".

 

For any mag loop, choose a frequency you wish to start work, somewhere in
the middle of the band.  Mag Loops are high Q antennas, that is they are
effective in a very narrow range of frequencies to which they are adjusted
with the tuning box.  This fact should inform your thoughts on effective
use.

Turn the tuning dial (ON THE MAG LOOP) until you hear the maximum amount of
noise (or blessed with a real signal).   The antenna and the radio are now
tuned.

Turn the KX3 tuning knob SLOWLY until you hear some kind of interesting
signal.  (PX3 is great for this too).  

Tweak the tuning knob on the mag loop to get the strongest signal for your
exact frequency. (just a tweak).   This is important even if you hear the
signal, to get the most efficient use of transmitter.

If while seeking a station you hear a lot less static, adjust the mag loop
as above.

 

IF seeking up and down the band, just rinse and repeat as above until you
get a station to work.

 

Once the mag loop is tuned to the band, you won't have to adjust it much to
tune it for the particular part of the band you are on. Gentle tweaks is the
way.  Notice too, mag loops are very directional. Consult the manufacturing
manual for where it's sensitive and turn it along a great circle to where
you want to go.  (In Boston, where I live, Europe is north east by great
circle.

 

I note there is something about tuning the radio in some mag loop
instructions.  I find this not necessary with the KX3.  What I describe here
is what I do and it works well.

 

I have contacted Europe USB with a KX3 at 15 watts and a mag loop.  The
antenna was on the top floor of my wood frame town house for this, not even
outdoors.  If you think about what I wrote, you want the antenna in arm's
length while working the radio.  Don't worry about your body affecting the
near field. Mag Loops are not like that.

 

-73-

W1GCF

Geoff

__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com