EFHW Antenna Experimetation Board


Jim Sheldon
 

Mine is out for delivery by the Post Office (thanks Johnny) and I'll have it around Noon. I plan on designing a 3D printed, weather resistant case/cover for it so that it can be left outdoors for reasonably extended periods to facilitate testing of the antenna configurations. The case will have a re-inforced hanger and a screw that passes through the "Strain" hole to make things a bit more sturdy (sometimes difficult to achieve with 3D printing). Once finished, I'll publish the FreeCad .step file, the Fusion 360 .f3d design files and the 3D printable .stl file on the 4S reflector as well as on www.thingiverse.com for everyone interested.

Jim, W0EB


Johnny AC0BQ
 

Gm Jim
Thanks for designing a enclosure for the kit.
I was thinking about it but my design skills are still in the beginner stage.
72
Johnny ACØBQ 

On Fri, May 6, 2022 at 8:54 AM Jim Sheldon <w0eb@...> wrote:
Mine is out for delivery by the Post Office (thanks Johnny) and I'll
have it around Noon.  I plan on designing a 3D printed, weather
resistant case/cover for it so that it can be left outdoors for
reasonably extended periods to facilitate testing of the antenna
configurations.  The case will have a re-inforced hanger and a screw
that passes through the "Strain" hole to make things a bit more sturdy
(sometimes difficult to achieve with 3D printing).  Once finished, I'll
publish the FreeCad .step file, the Fusion 360 .f3d design files and the
3D printable .stl file on the 4S reflector as well as on
www.thingiverse.com for everyone interested.

Jim, W0EB






--
Check out the 4SQRP website at 4sqrp.com


cornhusker
 

For all of the beginners in 3D printing, be sure to use PETG filament for outdoor permanent use.  
73 de K0NEB 


On Fri, May 6, 2022 at 8:54 AM, Jim Sheldon
<w0eb@...> wrote:
Mine is out for delivery by the Post Office (thanks Johnny) and I'll
have it around Noon.  I plan on designing a 3D printed, weather
resistant case/cover for it so that it can be left outdoors for
reasonably extended periods to facilitate testing of the antenna
configurations.  The case will have a re-inforced hanger and a screw
that passes through the "Strain" hole to make things a bit more sturdy
(sometimes difficult to achieve with 3D printing).  Once finished, I'll
publish the FreeCad .step file, the Fusion 360 .f3d design files and the
3D printable .stl file on the 4S reflector as well as on
www.thingiverse.com for everyone interested.

Jim, W0EB







Jim Sheldon
 

Hi Johnny,
It ain't designed yet, as the kit hasn't gotten here yet (later today), but I'll get on it this afternoon/evening and more if necessary.  I'll probably have to print a couple to tweak things before I publish it, but this is something I've needed for quite a while to go along with my Elecraft KX2 portable setup and will be small enough in the end to actually fit in the larger of the two carrying bags Elecraft sells for the KX2.  

I can't get started until I have the actual board in hand as the kit manual doesn't give the actual dimensions of the board and I'll need to have that BNC connector mounted to determine the size/placement of the hole for the connector.  I'm hoping it does come with the washer/nut that's usually included with those PC mount BNC connectors.  If not, I have a few on hand somewhere so that won't be a serious drawback.

There is at least one other person here that I know (K8ICY) that could do this as well (he got me started with Fusion360 as a CAD program) but he's been pretty busy working on the electronic stuff so I figured I'd take the bull by the horns so to speak and do this for the group.

BTW, if you and others haven't heard, W8DIZ (kitsandparts.com - the toroid king) had brain tumor surgery the other day.  He's still in the ICU but his wife says he's doing well and he'll be moved to a normal room in a few days.  

Jim, W0EB

------ Original Message ------
From "Johnny AC0BQ" <jomatlock@...>
Date 5/6/2022 9:04:27 AM
Subject Re: [4SQRP] EFHW Antenna Experimetation Board

Gm Jim
Thanks for designing a enclosure for the kit.
I was thinking about it but my design skills are still in the beginner stage.
72
Johnny ACØBQ 

On Fri, May 6, 2022 at 8:54 AM Jim Sheldon <w0eb@...> wrote:
Mine is out for delivery by the Post Office (thanks Johnny) and I'll
have it around Noon.  I plan on designing a 3D printed, weather
resistant case/cover for it so that it can be left outdoors for
reasonably extended periods to facilitate testing of the antenna
configurations.  The case will have a re-inforced hanger and a screw
that passes through the "Strain" hole to make things a bit more sturdy
(sometimes difficult to achieve with 3D printing).  Once finished, I'll
publish the FreeCad .step file, the Fusion 360 .f3d design files and the
3D printable .stl file on the 4S reflector as well as on
www.thingiverse.com for everyone interested.

Jim, W0EB






--
Check out the 4SQRP website at 4sqrp.com


Jim Sheldon
 

A bit of further info on printing materials as reiteration to K0NEB's post.  PETG is not strictly necessary as a 3D print material for outdoor use.  It will stand up better to sunlight and the elements than the old, original PLA which is the most popular and easiest material to print with (also generally the cheapest).  That being said, current formulations of PLA filaments by various manufacturers are known as PLA+, PLA2, HT-PLA+ and several other versions.  My favorites are PLA2 and HT-PLA+ by a US manufacturer called FilaCube (see Amazon or FilaCubes website www.filacube.com).  I've had some 3D printed dipole center insulators & end insulators up in the air for over 2 years now that were printed with their PLA+ and they are still hanging with no visible damage due to sunlight or the summer/winter temperature changes and they have survived 60+ mph winds as well.   My QTH is in Kansas after all - LOL.   Also, using lighter colors will help allay fears of the sun's heat melting the PLA which has been a touted fear of many for years and with the newer PLA materials, totally unfounded as well.  

Most antenna experimenters and portable operators never have antennas hanging under strain that long so for these purposes, PETG (which is sometimes difficult to get to print right and most new guys to 3D printing learn very early on that unless you really need to use PETG, you leave it alone - LOL) should NOT be used for experimenting.

If you have an antenna configuration that works well using this EFHW experimenter board, and plan to make a permanent QRP (or with a different toroid than supplied) up to 100 watt EFHW antenna installation then by all means use PETG as the cover for this kit.  The print files I'll provide will work with either material, but as I said, PETG is not strictly necessary except for extreme long term use. 

Jim, W0EB

------ Original Message ------
From "cornhusker via groups.io" <cornhusker@...>
Date 5/6/2022 9:11:29 AM
Subject Re: [4SQRP] EFHW Antenna Experimetation Board

For all of the beginners in 3D printing, be sure to use PETG filament for outdoor permanent use.  
73 de K0NEB 


Alex (KD0YTE) <afleak@...>
 

I will second W0EB's post I have a pla printed balun box that has been in the sun for over 2 years and hasn't degraded yet. 
When I printed it I made the walls thicker than those of a pvc balun box and I think that prevents warping. etc. Sure some day i will have to replace it but a well printed pla item can last quite a while in the sun.


John - KK4ITX
 

I don't doubt that what you imply is absolutely true for your QTH(s) but I am willing to test your theory here in FL within a few miles of where the record stands for sunny days.  The sun here destroys plastic, car finishes and the coatings over car finishes. Painted surfaces start fading overnight it seems. Granted much of what turns to dust was made "over there" but still.....

Send me a sample of whatever and I'll put it up under stress conditions for a year (probably equal to 5 years elsewhere) and we'll see what happens, I will take photos, measurements and keep you posted on the results and send the item back to you at the end of a year. 

Interested ?

John
KK4ITX
Zephyrhills, FL




Click Here for Zephyrhills Area Amateur Radio Club
Many of life's failures are people who
did not realize how close they were to
success when they gave up.
       Thomas A. Edison     


On Saturday, May 7, 2022, 01:31:11 PM EDT, Alex (KD0YTE) <afleak@...> wrote:


I will second W0EB's post I have a pla printed balun box that has been in the sun for over 2 years and hasn't degraded yet. 
When I printed it I made the walls thicker than those of a pvc balun box and I think that prevents warping. etc. Sure some day i will have to replace it but a well printed pla item can last quite a while in the sun.

--
John, KK4ITX       # 1603