Re: Any info about making air variable capacitors, and magnetic loops?
If the efficiency is too low, increase the diameter of the loop or the diameter of the conductor. I am using a 7' square and a 30pf variable cap for 10M.? It is made of 3/4" copper. The calculator link I provided has a check in it, it will tell you if the loop is too big or small for the frequency you are working with.
Keep experimenting!
Marco - KG5PRT
On Wed, Jun 21, 2017 at 11:54 AM, John Smith via Groups.Io <johnlinux77@...> wrote: I have seen both ways too, but at least one youtuber showed that with the feed loop at the bottom and the tuner cap at the top, the radiated pattern goes up and out mostly at 45 degree angle.
I am loving att this info. Next question is how do I know how much capacitance I need for the tuning cap? I would like a 40 meter band mag loop. but the calculators indicate 40 is impractical, and will suffer too much inefficiency. Much worse than my dipole.?
And must the homemade butterfly cap be made with brass rods and nuts? Or will standard hardware do the trick without a significant problem?
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Very high clicks after cw wiring
i have added a button for a tunning button after that i got nothing so i thought i'd wire the whole cw wiring I got them all following instructions button still does nothing the only one i didn't wire was pin15 to that transistor as inam not going to use cw by the way, any hint why it doesn't work the carrier button (brown wire from p1) 
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Re: Any info about making air variable capacitors, and magnetic loops?
I have seen both ways too, but at least one youtuber showed that with the feed loop at the bottom and the tuner cap at the top, the radiated pattern goes up and out mostly at 45 degree angle.
I am loving att this info. Next question is how do I know how much capacitance I need for the tuning cap? I would like a 40 meter band mag loop. but the calculators indicate 40 is impractical, and will suffer too much inefficiency. Much worse than my dipole.?
And must the homemade butterfly cap be made with brass rods and nuts? Or will standard hardware do the trick without a significant problem?
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Re: Any info about making air variable capacitors, and magnetic loops?
Thanks!
That calculator like my 2 10' sticks of 3/4'' copper pipe.? Only
a little copper wasted to get the Cap in there.
I have most the fittings.? I read you can put the control wires
inside!? Sure why not?
I have seen designs with the Cap on top and bottom?
It is my understanding that under the matching loop top or bottom
is where you could actually connect ground together if you want.
If the most RF is at the Cap,? should it be at the top, farthest
from earth ground?
I have seen both ways, for now I guess CAP at top?
Mike, WA6ISP
On 6/21/2017 6:59 AM, M Garza wrote:
toggle quoted message
Show quoted text
Here are a couple of pdf articles that might help.
Marco - KG5PRT?
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Re: BITX QSO Night, Sunday, June 25, 7pm Local Time, 7277 kHz in North America, 7177 kHz elsewhere
Conditions were not the best so I waited for the ionosphere to thicken ( during and after twilight ) and made these contacts.....
??????????????????? S / R
VE3THR- 33? 33
KA9OOI- 57 55
AA4PG-??? 55 55
N2CQR (100W BITX)-? 57 33
W1LY-??? 59 57
And I heard:
N9ARZ- 55
WB1FSZ-57
W0OIC- 55...33 QSB
WC1KSZ- 55
I'm using a dipole feed at only 15ft.
On Jun 20, 2017 3:17 PM, "KC8WBK via Groups.Io" <cruisenewsnet= [email protected]> wrote:
BITX QSO Night, Sunday, June 25, 7pm Local Time, 7277 kHz in North America, 7177 kHz elsewhere
Join us as we make contacts from BITX40 to BITX40 on 7.277 MHz in 40 meters!
To participate, call CQ BITX at 7pm sharp, your local time, on Sunday. Call off and on for about 15 minutes. It is helpful if you call CQ BITX with your name and location.? Repeat your call a number of times if conditions are weak.
This is a worldwide event at 7pm in each time zone.? You may participate in any time zone, regardless of your location, so you may wish to call in at 6pm, 7pm and 8pm, your local time, to contact hams in adjacent time zones.
The backup frequency in case of QSB or other noise is 7210 kHz.
Report your QSO's, discuss propagation, noise, signal reports, audio reports, antenna type, etc. in this thread.
This is an undirected, scheduled event.? The BITX QSO Night relies on you to call CQ BITX to initiate contacts with other stations, so warm up that final and transmit a few calls at 7pm on Sunday.? Talk to you then!
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Re: Any info about making air variable capacitors, and magnetic loops?
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Re: Any info about making air variable capacitors, and magnetic loops?
Link didn't work!
Google MFJ Loop Tuner
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Re: Any info about making air variable capacitors, and magnetic loops?
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Ordered on June 15, received June 20, SN: 4/297 Excellent service!
Al, N8WQ
On Tue, 20 Jun 2017 23:18:08 -0400, Jack Purdum via Groups.Io <econjack@...> wrote:
Ordered on June 12, received June 20, SN's: 4/270, 4/376
Jack, W8TEE
-- Using Opera's mail client:
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Re: Any info about making air variable capacitors, and magnetic loops?
Here are a couple of pdf articles that might help.
Marco - KG5PRT?
On Jun 21, 2017 8:34 AM, "Michael Hagen" < motdog@...> wrote:
I have never heard an outside signal on my bit40.? Testing with a
signal generator I get signals down to or below 10uV?
I have no antenna, but a wire out the door brings in nothing but
a little more noise.
To make others happy, I could hide the loop when not
experimenting.? No one I know nowadays knows what a Ham is!
I am gathering parts for a loop.? I got 8 3/4" 45 Degree "El".? I
am going to get 2 10' sticks of the thinner 3/4" copper pipe.
If I cut to 8 pieces, there will be 2 1/2 ft. per section.? So
the loop should be 6 ft or so.
I found an online store an got the copper fitting a lot cheaper
than the Home Depots around here.? About 1$ a fitting.
There is an L and M designation.?? For the drive loop, the
hardware stores sell rolls of 1/4" copper tubing.
To get started just to receive, the little Polyester AM radio
capacitors will work.? With a real high Q, I will just tune for
noise (I hope).
I have seen people put big wire or coax in Hula Hoops. But not Tin
Foil?? To maintain High Q, you might need less resistance?
If I have any results that warrant the expense, I will buy a vacuum
variable.? But the $3 AM radio variable is used everywhere and
in a lot of low power Ham projects.
Mike, WA6ISP
On 6/21/2017 12:08 AM, M Garza wrote:
When I built my 10M loop, I used this calculator:
I liked this calculator, since it provides
approximate voltages the cap will see and I could play with
the figures to see the outcome.
Depending on the rf power, you could see several
thousand volts at the cap.? They also have a capacitor
calculator, you could use that to design a cap.
You could use coax capacitors, high voltage
caps, air variables, trombone style, or vacuum variables, just
to name a few.? Search you tube, there are a ton of examples.
I am feeding the loop with a toroid and 3 turns
of #12 wire.? Similar to VK6CS in these videos:
To connect a motor to the cap, use some kind of
insulated shaft coupler to keep the high voltage off the
motor.? Make sure to bypass the motor terminals with a 0.1uf
cap to try and keep the rf out of the motor.? I would suggest
a geared motor, ?something with a low RPM.? You could vary the
voltage to the motor, to control tuning speed.
Hope that helped some.
Marco - KG5PRT?
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Re: ADAPTER BOARD - REDUX
I'll take one please.
Pete KI6SSI
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Re: Any info about making air variable capacitors, and magnetic loops?
Take a look at the "midnight loop" project (pdf at ). Both the loop and the variable air-gap capacitor are made from a single piece of 10 inch wide aluminum flashing.
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Re: Any info about making air variable capacitors, and magnetic loops?
I have never heard an outside signal on my bit40.? Testing with a
signal generator I get signals down to or below 10uV?
I have no antenna, but a wire out the door brings in nothing but
a little more noise.
To make others happy, I could hide the loop when not
experimenting.? No one I know nowadays knows what a Ham is!
I am gathering parts for a loop.? I got 8 3/4" 45 Degree "El".? I
am going to get 2 10' sticks of the thinner 3/4" copper pipe.
If I cut to 8 pieces, there will be 2 1/2 ft. per section.? So
the loop should be 6 ft or so.
I found an online store an got the copper fitting a lot cheaper
than the Home Depots around here.? About 1$ a fitting.
There is an L and M designation.?? For the drive loop, the
hardware stores sell rolls of 1/4" copper tubing.
To get started just to receive, the little Polyester AM radio
capacitors will work.? With a real high Q, I will just tune for
noise (I hope).
I have seen people put big wire or coax in Hula Hoops. But not Tin
Foil?? To maintain High Q, you might need less resistance?
If I have any results that warrant the expense, I will buy a vacuum
variable.? But the $3 AM radio variable is used everywhere and
in a lot of low power Ham projects.
Mike, WA6ISP
On 6/21/2017 12:08 AM, M Garza wrote:
toggle quoted message
Show quoted text
When I built my 10M loop, I used this calculator:
I liked this calculator, since it provides
approximate voltages the cap will see and I could play with
the figures to see the outcome.
Depending on the rf power, you could see several
thousand volts at the cap.? They also have a capacitor
calculator, you could use that to design a cap.
You could use coax capacitors, high voltage
caps, air variables, trombone style, or vacuum variables, just
to name a few.? Search you tube, there are a ton of examples.
I am feeding the loop with a toroid and 3 turns
of #12 wire.? Similar to VK6CS in these videos:
To connect a motor to the cap, use some kind of
insulated shaft coupler to keep the high voltage off the
motor.? Make sure to bypass the motor terminals with a 0.1uf
cap to try and keep the rf out of the motor.? I would suggest
a geared motor, ?something with a low RPM.? You could vary the
voltage to the motor, to control tuning speed.
Hope that helped some.
Marco - KG5PRT?
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I use 1.75mm Filament.? I use Simplify3D set to 30% fill and
0.1mm layer.? I have setup in Inches, I can see relative size when
the part loads.
The big knob loads with the bottom (hollow parts up), so I flip
it with the top of the knob UP.?? I tell Simplify3D to use
SUPPORTS.
Print time is a little less than 1 1/2 Hours.
You picture looks like you were printing the smaller volume knob.? I
put a pointer on it (of a fashon).
You printer is really printing perfect.? I have never seen parts any
better!
Sounds like a Inches vs mm problem in setting?
Tell us what printer and filament you are using, the Box looks
prefect, especially with the thin walls.
They look really good.
Mike, WA6ISP
?
On 6/21/2017 2:58 AM, bjorn wrote:
toggle quoted message
Show quoted text
here is a pic of the one I printed without checking...
On 2017-06-21 10:35, bjorn wrote:
Are you sure you sent the correct.stl files?
The one I printed came out huge and when checking the other
one a bit more carefully after slicing, it would have been
even bigger.
137.5 x 137.5 x 75 mm, 2 days and 5 hours printing time, 37m
filament.
Or are your units not mm?
On 2017-06-20 15:13, Michael Hagen
wrote:
I used Black PLA and the long print time for better print.
On 6/20/2017 6:08 AM, Michael
Hagen wrote:
Encoder or Pot
On 6/20/2017 5:51 AM, Matt
Patterson wrote:
Those look awesome. Any chance you might share?
Matt
W5LL
Sent from my iPhone 7
On Jun 20, 2017, at 7:47 AM, Michael Hagen <motdog@...> wrote:
Here are some knobs I drew up and printed. Also an LCD Bezel. I have a speaker mount and grill ready to put in too.
Mike, WA6ISP
On 6/19/2017 6:51 PM, Matt Patterson wrote:
Anyone else here have a 3D printer? Anyone found some good looking knobs for the front? I'm printing a couple I found on thingiverse right now but not sure how well they're going to work out.
73 Matt
W5LL
<RaduinoXFRONT1.jpg>
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Re: Raduino v1.15.1 with small bug correction released
Is there any plans to make pre-programmed memories?
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The big knob is 1.4" x 0.7".? You probably need to covert units?
On 6/21/2017 2:58 AM, bjorn wrote:
toggle quoted message
Show quoted text
here is a pic of the one I printed without checking...
On 2017-06-21 10:35, bjorn wrote:
Are you sure you sent the correct.stl files?
The one I printed came out huge and when checking the other
one a bit more carefully after slicing, it would have been
even bigger.
137.5 x 137.5 x 75 mm, 2 days and 5 hours printing time, 37m
filament.
Or are your units not mm?
On 2017-06-20 15:13, Michael Hagen
wrote:
I used Black PLA and the long print time for better print.
On 6/20/2017 6:08 AM, Michael
Hagen wrote:
Encoder or Pot
On 6/20/2017 5:51 AM, Matt
Patterson wrote:
Those look awesome. Any chance you might share?
Matt
W5LL
Sent from my iPhone 7
On Jun 20, 2017, at 7:47 AM, Michael Hagen <motdog@...> wrote:
Here are some knobs I drew up and printed. Also an LCD Bezel. I have a speaker mount and grill ready to put in too.
Mike, WA6ISP
On 6/19/2017 6:51 PM, Matt Patterson wrote:
Anyone else here have a 3D printer? Anyone found some good looking knobs for the front? I'm printing a couple I found on thingiverse right now but not sure how well they're going to work out.
73 Matt
W5LL
<RaduinoXFRONT1.jpg>
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Re: BITX QSO Night, Sunday, June 25, 7pm Local Time, 7277 kHz in North America, 7177 kHz elsewhere
This is Field Day weekend, so I probably won't be on Sunday night, but with a little luck, I'll be using the BitX for our Field Day operation under the call sign K2OAK.
--
John - WA2FZW
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here is a pic of the one I printed without checking...
On 2017-06-21 10:35, bjorn wrote:
toggle quoted message
Show quoted text
Are you sure you sent the correct.stl files?
The one I printed came out huge and when checking the other one
a bit more carefully after slicing, it would have been even
bigger.
137.5 x 137.5 x 75 mm, 2 days and 5 hours printing time, 37m
filament.
Or are your units not mm?
On 2017-06-20 15:13, Michael Hagen
wrote:
I used Black PLA and the long print time for better print.
On 6/20/2017 6:08 AM, Michael Hagen
wrote:
Encoder or Pot
On 6/20/2017 5:51 AM, Matt
Patterson wrote:
Those look awesome. Any chance you might share?
Matt
W5LL
Sent from my iPhone 7
On Jun 20, 2017, at 7:47 AM, Michael Hagen <motdog@...> wrote:
Here are some knobs I drew up and printed. Also an LCD Bezel. I have a speaker mount and grill ready to put in too.
Mike, WA6ISP
On 6/19/2017 6:51 PM, Matt Patterson wrote:
Anyone else here have a 3D printer? Anyone found some good looking knobs for the front? I'm printing a couple I found on thingiverse right now but not sure how well they're going to work out.
73 Matt
W5LL
<RaduinoXFRONT1.jpg>
|
Are you sure you sent the correct.stl files?
The one I printed came out huge and when checking the other one a
bit more carefully after slicing, it would have been even bigger.
137.5 x 137.5 x 75 mm, 2 days and 5 hours printing time, 37m
filament.
Or are your units not mm?
On 2017-06-20 15:13, Michael Hagen
wrote:
toggle quoted message
Show quoted text
I used Black PLA and the long print time for better print.
On 6/20/2017 6:08 AM, Michael Hagen
wrote:
Encoder or Pot
On 6/20/2017 5:51 AM, Matt
Patterson wrote:
Those look awesome. Any chance you might share?
Matt
W5LL
Sent from my iPhone 7
On Jun 20, 2017, at 7:47 AM, Michael Hagen <motdog@...> wrote:
Here are some knobs I drew up and printed. Also an LCD Bezel. I have a speaker mount and grill ready to put in too.
Mike, WA6ISP
On 6/19/2017 6:51 PM, Matt Patterson wrote:
Anyone else here have a 3D printer? Anyone found some good looking knobs for the front? I'm printing a couple I found on thingiverse right now but not sure how well they're going to work out.
73 Matt
W5LL
<RaduinoXFRONT1.jpg>
|
