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>
|
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>
|
Re: Any info about making air variable capacitors, and magnetic loops?
I forgot to mention: I do not need a tuner, the antenna matches perfectly, 1:1.? The variable cap is the tuner.? I get about 200 kHz bandwidth before I have to retune. You would not want to use aluminum and galvanized metal.? You need to bond the metals, ie. solder or weld.? I do not know of a way to do that with those two metals.? The connection needs to have the lowest resistance possible or it could greatly impact efficiency. You could try copper or silver tape and brass bolts.? Maybe copper flashing.
73s
Marco - KG5PRT?
On Jun 21, 2017 2:09 AM, "M Garza" < mgarza896@...> 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?
|
Re: Any info about making air variable capacitors, and magnetic loops?
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?
On Jun 21, 2017 1:17 AM, "John Smith via Groups.Io" <johnlinux77= [email protected]> wrote: I have some plans and ideas, but thought I should consult with the smartest group of people I know. Can I use zinc plated hardware with aluminum roof flashing? How to attach a arduino stepper motor to caps rotor shaft? Cheat on the loop by covering a hula hoop with aluminum foil? And I still need a antenna tuner after tuning the cap for resonance, Right?
Have any mag loop calculators, or instruction sites. Hopefully I will find more than I've seen so far.? Good instructional homebrew videos on youtube are great too
Thanks in advance de KG5KYJ
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Re: Raduino v1.15.1 with small bug correction released
Installed! Working good. I did not manage to use the brown wire for the tuner, but i guess i did something wrong...
Great to see people like you determined to make this rig shine
hasta la vista!
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Any info about making air variable capacitors, and magnetic loops?
I have some plans and ideas, but thought I should consult with the smartest group of people I know. Can I use zinc plated hardware with aluminum roof flashing? How to attach a arduino stepper motor to caps rotor shaft? Cheat on the loop by covering a hula hoop with aluminum foil? And I still need a antenna tuner after tuning the cap for resonance, Right?
Have any mag loop calculators, or instruction sites. Hopefully I will find more than I've seen so far. ?Good instructional homebrew videos on youtube are great too
Thanks in advance de KG5KYJ
|
Re: ADAPTER BOARD - REDUX
toggle quoted message
Show quoted text
On Jun 20, 2017 21:07, "K5ESS" < k5ess.nothdurft@...> wrote:
I'm planning on ordering more of the Type I to Type II DDS adapter boards.? They will be a re-spin that corrects the Sine 1 connections that required a modification to the previous boards.? Anyone interested let me know so I can size the order appropriately.? It will take two to three weeks after I order them before I can ship/
Mike
K5ESS
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Re: ADAPTER BOARD - REDUX
Mike, As you are going for fresh pcbs,? perhaps It is worth? to incorporate? Auto level control , that helps near constant level at all frequencies. There are such mods for AD9850 /51.
On Wednesday, 21 June 2017 9:00 AM, Larry Przyborowski <k3peg@...> wrote:
Hi Mike,
I'd like three of them, please.
73, Larry K3PEG
On 6/20/2017 10:07 PM, K5ESS wrote:
I'm planning on ordering more of the Type I to Type II DDS
adapter boards.? They will be a re-spin that corrects the Sine 1
connections that required a modification to the previous
boards.? Anyone interested let me know so I can size the order
appropriately.? It will take two to three weeks after I order
them before I can ship/
Mike
K5ESS
|
Re: ADAPTER BOARD - REDUX
Hi Mike,
I'd like three of them, please.
73, Larry K3PEG
On 6/20/2017 10:07 PM, K5ESS wrote:
toggle quoted message
Show quoted text
I'm planning on ordering more of the Type I to Type II DDS
adapter boards.? They will be a re-spin that corrects the Sine 1
connections that required a modification to the previous
boards.? Anyone interested let me know so I can size the order
appropriately.? It will take two to three weeks after I order
them before I can ship/
Mike
K5ESS
|
