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Bayou Jumper kit back in stock!
Lee Bahr
I was up late last night and saw the order desk was again opened for the Bayou Jumper. I never thought I would want one until they were no longer available! My friend Curt, KB5JO got an early one and really likes it. He got interested in Super Regenerative receivers and built a tube type regenerative receiver which has no front end. Of course the antenna swinging in the wind, made it unstable for regeneration. Then he purchased the Bayou Jumper and it does have a front end. With it he finds the receiver very stable and an antenna swinging in the wind has no effect on the Bayou Jumper's regenerative setting. He tells me the Bayou Jumper Regenerative Receiver with a Front End works great with it. Of course a Regenerative Receiver also has great sensitivity and some good selectivity too. So I am now HOOKED!
Lee, w0vt
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Bayou Jumper kit back in stock!
Ge group -- I am pleased to announce that the latest version of the Bayou Jumper is Transceiver kit is back in stock. While everything around us keeps rising in price, we have been able to hold the line on this kit, and we are offering it at the same price it was almost a year ago. This version has a new vibrant Red face plate as well as some part updates that will allow the use of a low current external keyer. Many thanks goes out to the great group of volunteers that have pulled this kit together!! You can find this kit at : Have a great weekend, 72 Johnny ACØBQ Check out the 4SQRP website at 4sqrp.com
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Re: Coil forms, Q, and instruments
davemrtn
Thanks for all the info Jim.
David Martin - NA1MH - Mountain
Home, Ar.
----------------------------------------- Wherever I go, there He is.
On 7/24/2021 6:19 AM, Jim Sheldon
wrote:
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Re: 40/20 meter trap dipole Coil Forms & insulators
davemrtn
Jim, Thanks. I was able to open all the F360 files.
David Martin - NA1MH - Mountain
Home, Ar.
----------------------------------------- Wherever I go, there He is.
On 7/24/2021 11:04 AM, Jim Sheldon
wrote:
As promised, here is a ZIP file of the Fusion 360 design files and the .stl. 3D printable files for the 40/80 trap dipole end/trap insulators, trap coil forms (Wind with 15 turns of #20 enameled wire) and the parallel capacitor should be a 1KV Mica cap of 27 pF -- Look up the wire lengths for the antenna as it will vary for each individual's chosen frequency so not indicating it here. Obviously will require pruning anyway as nobody has the same conditions for their installation.
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Re: 40/20 meter trap dipole Coil Forms & insulators
Some pictures of the center insulators - one for an SO-239 and one for a BNC connector. The blue one is for the SO-239 and the grey one is for the BNC. It was quicker to print them both at the same time (different printers) so I could get the corrected files tested and posted. Jim, W0EB
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Re: 40/20 meter trap dipole Coil Forms & insulators
Please disregard the Zip file in the original post. There are 2 problematical errors in the Center Insulators. The SO-239 mounting holes are too far apart and the BNC mounting hole is too small in diameter.
Those files have been corrected and the ones in the attached ZIP archive are now correct. Please use this one and not the first one. Thanks, Jim Sheldon, W0EB
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3D Print Roller Inductor... perhaps not.... but ...
Jim, N5IB
Jerry commented yesterday, "Does anyone see a roller inductor in the making???"
That's most likely well beyond my 3D skillset, and making the reliable moving contacts would be a real challenge. But a continuously variable inductance is a real plus in impedance matching networks. And for some configurations that have a single LC pair that produces a match, it's essential. The "Differential T" is one of those. Always wanted to make one with more QRP-friendly dimensions than the big MFJ version. Linking two common variable caps with 3D printed gears to make them act as a differential should not be hard. And, recall that it's possible to change the effective inductance of a coil by introducing material into the interior of the winding. If it's ferromagnetic, like iron powder or ferrite, the inductance increases. If is non-ferrous, like brass or aluminum, the inductance decreases. Think of the PTO (permeability tuned oscillator) devices that have been popular, like TenTec's rigs and Steve Weber's MMR40 transceiver. So I have an experiment under way to try to create a "PTI" (permeability tuned Inductor). I'm 3D printing a coil form with an inner cylinder that will hold a length of 3/8" diameter aluminum rod, able to slide in and out of the coil. Alternatively a ferrite rod, or an iron powder "rod" made by stacking several toroid cores. We'll see what kind of inductance range is achievable. It will also be necessary to investigate the losses. I seem to recall an article quite a few years back that implied the non-ferrous insert acted like shorted turns and did not impact the Q. In fact I'm almost certain there was an article in one of the ham mags a ways back about an antenna matcher that used this very principle. I like to invite folks who are so inclined and have the tools to join in this experimentation - we might come up with a nifty doodad. Jim, N5IB
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40/20 meter trap dipole Coil Forms & insulators
As promised, here is a ZIP file of the Fusion 360 design files and the .stl. 3D printable files for the 40/80 trap dipole end/trap insulators, trap coil forms (Wind with 15 turns of #20 enameled wire) and the parallel capacitor should be a 1KV Mica cap of 27 pF -- Look up the wire lengths for the antenna as it will vary for each individual's chosen frequency so not indicating it here. Obviously will require pruning anyway as nobody has the same conditions for their installation.
This is designed primarily as a portable dipole/doublet/inverted Vee to take on SOTA, POTA and other outings but depending on the material you print it with, it could have use in semi-permanent installations. Rudimentary printing instructions are contained in a text file within the ZIP archive. Jim Sheldon, W0EB
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Re: Coil forms, Q, and instruments
Dave, I'm using PLA2 or PLA+ both which are much easier to print with than PETG or ABS and are virtually NON-Toxic (ABS sure isn't). I have found that the PLA2 and PLA+ both last quite well outdoors, even in sunlight as I have a bunch of garden characters that have been out in the sun, rain, snow and all sorts of other weather for over 2 years with very little degradation, mainly only a slight fading of the colors. These antenna coil forms and insulators are designed for temporary portable antenna use and not really intended for permanent outdoor installs anyway, but I do intend to put one up in a semi-permanent install here at the house, just to test outdoor longevity. I used FilaCube "Mint Blue" PLA2 for the ones in the pictures. The tolerances on the coil inserts are pretty tight so not sure how PETG or ABS would print - each persons printers tend to print a bit different depending on machine tolerances and personal print profiles. I won't publish my print profiles as I'm using Creality CR10V2 printers and most people out there are using something else. There are two versions of the coil form, one with no "No Twist" inserts and one without that will be in the STL file when I get it ready for posting later today as well. The one without the inserts is for use in "Tank" coils, etc. It was an original experiment just to give more defined grooves for the coil than the one that Jim G. came up with using TinkerCad and through a sheer stroke of luck, wound with 16 turns of #20 it came out almost dead on the 4.7uH necessary for a 20 meter trap coil - I did not plan it that way - LOL. Jim
------ Original Message ------
From: "davemrtn" <davemrtn@...>
Sent: 7/23/2021 8:17:58 PM
Subject: Re: [4SQRP] Coil forms, Q, and instruments Jim, what material are you printing with, PETG ??? I wouldn't use PLA, but ABS would last longer than PLA, but I think PETG might last the longest ??
David Martin - NA1MH - Mountain
Home, Ar.
-----------------------------------------
Wherever I go, there He is.
On 7/23/2021 8:01 PM, Jim Sheldon
wrote:
Jim G's work inspired me to work on a 40/20 meter trap doublet/dipole/inverted vee with 3D printed trap coil forms and insulators. I have the traps coil forms done and the end/trap center insulators done and I really got lucky. A 20 meter trap should have 4.7 uH worth of inductance with a 27pF capacitor to resonate at 14.100 MHz and TOTALLY by accident, my initial print of the coil form wound with 16 turns of #20 wire just so happened to come out to just a bit over 4.7uH when I measured it.
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Re: Coil forms, Q, and instruments
Do a google search on Fusion 360 for personal use and you should find their newer instructions.
------ Original Message ------
From: "davemrtn" <davemrtn@...>
Sent: 7/23/2021 8:13:59 PM
Subject: Re: [4SQRP] Coil forms, Q, and instruments Jim, I had the original hobbyist version and Autodesk said my "free trial" was over ! I tried to sign up again for hobbyist license and couldn't find a means to do it. Points would be appreciated. In the mean time, I am getting better at using FreeCad.
David Martin - NA1MH - Mountain
Home, Ar.
-----------------------------------------
Wherever I go, there He is.
On 7/23/2021 4:41 PM, Jim Sheldon
wrote:
Dave,
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Re: Coil forms, Q, and instruments
davemrtn
Jim, what material are you printing with, PETG ??? I wouldn't use PLA, but ABS would last longer than PLA, but I think PETG might last the longest ??
David Martin - NA1MH - Mountain
Home, Ar.
----------------------------------------- Wherever I go, there He is.
On 7/23/2021 8:01 PM, Jim Sheldon
wrote:
Jim G's work inspired me to work on a 40/20 meter trap doublet/dipole/inverted vee with 3D printed trap coil forms and insulators. I have the traps coil forms done and the end/trap center insulators done and I really got lucky. A 20 meter trap should have 4.7 uH worth of inductance with a 27pF capacitor to resonate at 14.100 MHz and TOTALLY by accident, my initial print of the coil form wound with 16 turns of #20 wire just so happened to come out to just a bit over 4.7uH when I measured it.
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Re: Coil forms, Q, and instruments
davemrtn
Jim, I had the original hobbyist version and Autodesk said my "free trial" was over ! I tried to sign up again for hobbyist license and couldn't find a means to do it. Points would be appreciated. In the mean time, I am getting better at using FreeCad.
David Martin - NA1MH - Mountain
Home, Ar.
----------------------------------------- Wherever I go, there He is.
On 7/23/2021 4:41 PM, Jim Sheldon
wrote:
Dave,
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Re: Coil forms, Q, and instruments
I will Joe. I have a couple more things before I post the complete package. I still need to design a center insulator to take a BNC connector and one to take an SO-239 before I post the files.
toggle quoted messageShow quoted text
I’ll work on those tomorrow after breakfast and hopefully have a zipfile with all the .stl and I’ll include the .f3d files for those who can use them. Jim
On Jul 23, 2021, at 8:53 PM, cornhusker via groups.io <cornhusker@...> wrote:
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Re: Coil forms, Q, and instruments
cornhusker
toggle quoted messageShow quoted text
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Re: Coil forms, Q, and instruments
Jim G's work inspired me to work on a 40/20 meter trap doublet/dipole/inverted vee with 3D printed trap coil forms and insulators. I have the traps coil forms done and the end/trap center insulators done and I really got lucky. A 20 meter trap should have 4.7 uH worth of inductance with a 27pF capacitor to resonate at 14.100 MHz and TOTALLY by accident, my initial print of the coil form wound with 16 turns of #20 wire just so happened to come out to just a bit over 4.7uH when I measured it.
I worked on the design (I used AudoDesk's (free for personal/non-commercial use) Fusion 360 as my CAD program. F360 gives a bit more finesse when making threaded cylinders than TinkerCad does. Taking Jim's advice, I also added blockers to the inside of the coil form so the insulator will slide tightly inside and allow you to wind the coil first and pick which 90 degree point gives you the best coil positioning. Here's a couple of pictures of the lot. Jim Sheldon, W0EB -- 3D printing is a super 2nd hobby to HamRadio --   
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Re: Coil forms, Q, and instruments
Jim, N5IB
Hi Lloyd,
I'm CPU limited and can't run the better CAD packages like Fusion360. So I've been using TinkerCad on-line, and it's been sufficient for most things I've needed. With Ultimaker Cura 4.6.2 as the slicer One day, with a better CPU, I'll move up. Jim, N5IB
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Re: Coil forms, Q, and instruments
Dave,
toggle quoted messageShow quoted text
Suggest you check again, Fusion 360 is still free for personal/non commercial use. I have been using F360 for 3 years now, legally licensed for personal use and have not had to pay a penny for it. Jim, W0EB
On Jul 23, 2021, at 4:37 PM, davemrtn <davemrtn@...> wrote:
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Re: Coil forms, Q, and instruments
davemrtn
FreeCad is not as intuitive as AutoDesk Fusion 360, but I am unwilling to pay their exorbitant price for hobby use. I have been designing things with FreeCad [on and off] for several months and becoming more comfortable using, not proficient, but very comfortable. It does have a few quirks (bugs) you will discover along the way but nothing you won't find a work around for. It is a bargain at 2 or 3 times the price !
David Martin - NA1MH - Mountain
Home, Ar.
----------------------------------------- Wherever I go, there He is.
On 7/23/2021 1:42 PM, WA4EFS wrote:
Hello Jim. Very nice work on the coil form. I test printed your .stl file and it came out perfectly. If you don't mind my asking which CAD application do you use? Some time ago I attempted a similar project in FreeCAD. However, I encountered difficulties and set it aside. 73, -Lloyd (wa4efs) -----Original Message----- From: main@4SQRP.groups.io [mailto:main@4SQRP.groups.io] On Behalf Of Jim, N5IB Sent: Friday, July 23, 2021 8:50 AM To: main@4SQRP.groups.io Subject: Re: [4SQRP] Coil forms, Q, and instruments Hi David, Here's the STL file, attached, and a photo. It's such a thin tube it needs a "brim" for buildplate adhesion There's a tiny hole at each end to pass the wire through to secure the turns. I plan to make another with multiple holes to accommodate different turn counts. Jim, N5IB
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Re: Coil forms, Q, and instruments
Jerry Brown
Does anyone see a roller inductor in the making??? They are hard to come by these days and the last one I bought was for a club build project linked here....a LC matching network for end fed half wavelength verticals.... A QRP version would be nice! 72, Jerry N4EO, ex-YI9EO
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Re: Coil forms, Q, and instruments
WA4EFS
Hello Jim. Very nice work on the coil form. I test printed your .stl file and it came out perfectly.
toggle quoted messageShow quoted text
If you don't mind my asking which CAD application do you use? Some time ago I attempted a similar project in FreeCAD. However, I encountered difficulties and set it aside. 73, -Lloyd (wa4efs)
-----Original Message-----
From: main@4SQRP.groups.io [mailto:main@4SQRP.groups.io] On Behalf Of Jim, N5IB Sent: Friday, July 23, 2021 8:50 AM To: main@4SQRP.groups.io Subject: Re: [4SQRP] Coil forms, Q, and instruments Hi David, Here's the STL file, attached, and a photo. It's such a thin tube it needs a "brim" for buildplate adhesion There's a tiny hole at each end to pass the wire through to secure the turns. I plan to make another with multiple holes to accommodate different turn counts. Jim, N5IB
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