Built a new EFHW transformer per K1RF's design criteria using three FT-240-52 toroids. Supposed to handle 1200W SSB

Nice tidy looking build.  What kind of wire/insulation is that?

14GA  M16878/4  Mil-Spec Type E. Teflon jacketed silver plated copper wire.

I approve of his use of 66 blocks and 25 pair cabling. Makes me think he has a telco background. I've seen cleaner...but for an amateur shack 10/10.

Tried formatting a laptop, and loading Andy's Ham Radio Linux.

Not enough hard disk space.

So, today, I broke a laptop.

Tomorrow I will try to make a boot disk for Xubuntu and and manually load WSJTX, JS8 Call and FLDigi

Eta; quite a bit harder to get WSJTX going on Xubuntu without Andy's presetup system. But I got it going.

While it's not amateur radio related, I spent a good chunk of this afternoon/evening trying to fix boot issues on a Dell 1L unit to build as a tftp/smb sever for maintianing and installing Linux and Windows via PXE at the office. For those that don't know, I work in a department at EF Johnson that deals with IoT solutions...so where radio meets IoT. Turns out for whatever reason, Debian 11 wasn't installing Grub in EFI mode the way the Dell bios liked. It would boot EFI for Windows...but not for any Linux distro. Finally got the bios updated to something that would be stable with legacy booting off a SSD.

Just a quick bump.  I got a drone pic of my antenna from up above.  The radials are surprisingly hard to see.  The shadows of the wires stand out more than the wires do.  I'll have to get another shot one day when it's overcast. I still need to get guy ropes on it.  I plan to do a circle of rocks around it too.  I don't have a lawn because we go on watering restrictions almost every year and this area is huge.  I will say that the antenna works.  I estimate a 10 or 12 dB improvement in reception over my wire antenna based on noise floor and received signal strength when switching from one antenna to the other.  That's like adding an amp, but at about 1/3 to 1/2 the cost when you figure in all the accessories.

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Interesting. What wire antenna are you using?

It's an EFHW cut for 40m and resonant on 40, 20, 15 and 10m.  It slopes from about 8 feet high at the feed end to 25 feet high at the far end.  It's oriented roughly SW to NE.  

I installed it almost 2 years ago.  I bought a telescoping aluminum flagpole to use as a support for it.  It has worked well enough to get enough stations for credit for WAS on lotw if I want to buy an ARRL membership to get it.

There are times when it seems there is no difference in received signal strength and times when it's a huge difference.  I guess it all depends on conditions.

When I first installed the vertical I didn't think it was all that much better.  Then a week later I was seeing tons of new DX in FT8 I'd never seen before.  France, Germany, Austria, Turkey, Italy, Spain, Denmark, Norway, etc.  I got a few of them, but also many did not respond.  Japan, Australia, NZ and Hawaii were easy enough on the wire antenna, but now they are really easy.

Update: Pretty much done with the rebar now.  I think a good amount of the output was warming the steel.  While a functional antenna can be made the range is limited to about 1/2 of what a dipole can do.  Next phase is to put the inductor windings on the outside of a 1 1/4 PVC pipe enclosure and elevate the start of the antenna to about 15 feet.  This is resulting in better SWR 1.4 and a much more narrow band of acceptable SWR within 80m.  High Q, low bandwidth, I suppose.  Will post pics when I clean it up a bit.  I am making local contacts on 80 so far, but no longer tune-able to 20m or 40m.

Anything can be an antenna if you are brave enough.

Here is version 3.  I need to order some capacitors and get rid of that external coax acting as a capacitor.  
Its prettier than the previous versions.

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Winding a coil with a steel center is going to be problematic for efficiency. Air core is the way to go, many use PVC pipe. Remember it isn't just about SWR. a dummy load has great SWR but horrible efficiency of radiation. Ditch the rebar it will kill the efficiency of he coil.

I have used a coil I made with the same wire as part of a counterpoise for QRP and it did work. You can tune counterpoise wires with a tuning circuit.

The best way to make a coil for a base loaded antenna would be to use math. There are online calculators that take your length of wire and your frequency and computer what value of coil you need to tune it to resonance.

Some things to keep in mind.

A wire that is 1/4 wavelength with appropriate counterpoise doesn't need a base coil. Works for odd multiples of 1/4 wavelength also. 1/4 wave fed wires have an impedance close to 50 ohms. This the high current feed point because it is the middle of a half wave.

Even multiples are called EFHW antennas and need a matching transformer to bring the high impedance of feeding at the end to close to 50 ohms. This is the high voltage feedpoint because it is at the end of he half wave.

Power = Current times Voltage, Voltage = current time resistance ( impedance ) so when current is high, voltage is low and vice versa, since power is the same across an antenna, at a point on the antenna that has high current and low voltage, the impedance is low and at a point that has has low current and high voltage the impedance is high.

For a solid state transmitter we certainly want low impedance without a transformer or we need to change the high impedance to low impedance using a 4:1 or endfed 49:1 UNUN.

Shorter wires ( like a mobile vertical ) have a capacitive impedance and require an inductor to cancel out the capacitance to achieve resonance.
Long wires have inductive impedance and require a capacitor to tune to resonance and cancel out the inductance.

Wires that are inbetween the 1/4 wavelength and 1/2 wavelength ( or the multiples of such ) are tuned to either the 1/4 wavelength low impendance or 1/2 wavelength high impedance. or somewhere inbetween impednace. using inductance, capacitance or both.

For 80 meters in your case, 1/4 wavelength is about 67 feet, 1/2 wavelength is about 134 feet.
Your 180 foot wire is 1.34 times the half wave so long compared to 1/2 wave and 2.68  times the 1/4 wave, short on 1/4 wave. ( short for odd multiple (3) of 1/4 WL )

So picking one, I would pick short on 1/4 WL so you don't need to use a transformer UNUN and only need a coil.  if you pick long you need capacitance and a transformer UNUN due to high impedance  

So you could tune it either way. tune to 1/2 wave with a capacitive circuit but with a high impedance needed a transformer match like an UNUN or tune to 1/4 wave multiple with an inductance circuit like a base coil getting close to 50 ohms.

Incidentally this is why when using a tuner you can get more than one solution. Inductors are more lossy than capacitors so the best solution is with the least inductance

Lets assume you pick the option of tune with a base inductor to not have to use a transformer, ( or an inductor and capacitive network like a tuner )

You need to calculate how much inductance you need and then use a calculator to decide what form factor you want , ie. radius and length of inductor

then build it and make small changes or make it variable because how that wire is oriented vertical, horizontal, sloper and how high off the ground it is will vary the impedance and the resonance and the value of he inductor needed.

You could do trial and error but without knowing where to start it is problematic and you may never get there.

You could also just shorten the wire to 135 feet and feed it in the center and make a dipole or shorten to 135 feet, feed from the endmake a 49:1 UNUN transformer and make an EFHW. This would be a mulitband antenna with a tuner.

180 feet is not going to be a multiiband antenna without a tuner that has inductors and capacitors.

You will take losses in the coax using an in the shack tuner or use a tuner at the antenna or cut the 180 wire in half, feed at the center with open line to massively reduce losses and use a tuner in the shack or variation of balun and open wire line and tuner in the shack.

There are lots of options.

I am no expert so some of the above may no be totally accurate but this is my limited understanding.

So it depends on how you want to do it.

ETA: as stated above, those coils on your pic are on a torroid to make a transformer, not on a piece of rebar. He shows how to make the torroid on the very page that diagram is taken from.

Mach:  Thanks for the detailed post.  All good information.  I am trying to the learn the basics of building tuner circuits and have covered much ground since the start of the project, with much more I am certain ahead.  It has been a very good exercise.

I put together a battery box with a charge controller, a couple of USB ports, a cig lighter connector, a volt meter. and two connections for solar and two power out connections with power poles.
I am getting correct voltages on all the outputs, but haven't tried the solar connection yet. I will post some pictures here soon.
9ah Bioenno battery, and a 10a renogy charge controller.
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Guy wires don't belong on the ground.


Towers should be straight too.  "Nope, I won't climb this one."  More photos to add to my fall protection class folder.


"The 50's called, they want their tech back."


but that phone goes well with the chair in the corner.


"Just crank 'er tight."


laz0r the dish and do some trig to measure heights





antenna's trash.  


Gonna be a project for sure.  Not a bad place for a project though, and it's right outside my winter home. (Put a LOT of snowmobile tracks on those mountains across the valley all winter.)

That guy makes me feel like a bad person.

I've spent the last few days getting some stuff together for performing a in-house training class on the Astronics/Freedom R8200. It's been about 5 years since I turned in my R8000 when I transferred branch offices and I hadn't touched a R8x00 since but have pulled out my (personal) R2670 a few times here to do some things. Not a ton has changed with the jump from the R8000 to R8200 but there are some new features which I either never had access to on my rep sample in 2014 because they weren't available yet or just simply never had on the R8000 that was issued to me. This is a brand new rep sample (i.e. it's fully whored out to put in terms that batwing guys would understand). I did play with the VNA and look at the RL across a full 130-870 MHz sweep to see how that VHF/7-800 MHz diplexer I installed in my pickup looked (good by the way, need to actually shorten the VHF whip a bit but 7/800 looked excellent up to 860 MHz as well).

I did not realize that I had several sets of serialized test cables laying around which also caused me to decide it's probably getting close to time to re-evaluate what I keep in my R2670's lid. So I wandered over to Mouser to pick up a handful of adapters (SMA female to N male, SMA female to Mini-U, SMA female to BNC male) and located my QMA female to N male adapter and SMA female to QMA female adapters for use with these test cables (one is SMA male on one end and QMA male on the other, one is QMA male on one end and N male on the other, the final is SMA male on both ends). Also got to play with the cable calibration feature on the R8200 (which was not something the R8000 had on it when I had access to it nor is it something my R2670 is capable of).

Also found a guy who is building a pretty kick-ass UHF duplexer right now in Plano, TX and got to see some of the cool things he's doing with that. He took a common design used by Motorola and made it better and is seeing about 120 dB of TX/RX isolation on four cavities where the Motorola version is more typical of about 95 dB of TX/RX isolation.

I was thinking of getting one of those Chameleon EMCOMM III antennas.  Until I saw some of the prices being asked.


Uhhh...
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I'm a filthy Poor, and I like building things, so I bought this $29 kit:


Which became this (pardon my crappy soldering)...


Crammed it into a $4 project box...


...added some DollarStore cutting board...


...and some wire left over from another project...





Initial testing looked promising.

Icom 7300 seemed to find a match rather quickly on all bands from 160-6 meters.
FT-891/AT100ProII-combo for some reason struggled quite a bit more and was unable to find a match in some cases.

I just need to find the time & place to set it up properly and see if it actually works worth a damn.  If it does, I figure I saved around $135 or so.

With my luck it will catch fire and explode, but I still had fun building it.

I put up an 11/10 meter 24' tall MAX2000 antenna for 10 meters at about 30'. Wow, this thing almost makes its own propagation.

The soldering looks okay to me.  That looks like a fun project.

Link to kit?

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Figured I'd give an end fed antenna a try. We will see how it goes!

14G solid copper on a 240-43 toroid should work for my 100 watts. Hopefully ft8 too.

Balun / Unun 5:1 250Ohms to 50Ohms for broadband HF vertical antenna

I did a little bit of research and found that Chameleon apparently uses this type of 5:1 UNUN for the EMCOMM III portable antenna (and a few others).  A search for DIY 5:1 UNUN showed some interesting scratch-built versions of the same basic design.  One photo led to that eBay site.  It looked better than the scratch-built ones and easy enough to build so I took a chance.

The kit ships from France and the instructions are obviously translated into English but are easy to follow.  Shipping time was reasonable, I ordered on 5/21 and received it on 6/2.

You have to supply the wire to loop through the toroids.  I read somewhere (but can't find it again) to use the insulated center conductor from a piece of 75ohm foam-core coax used for AV.  I had some of that left over from when I made a matching stub for the Butternut vertical to replace the broken original.

eta: The pictures on the eBay site look like normal wire, but I used the coax center conductor anyway.

I'd love to see a 160-6 Meter scan on NanoVNA-Saver of an actual CHA antenna to see how my DIY compares.  I know it's only rated from 3.5-60 MHz, but the 7300 was able to match on 160M also (probably inefficient as hell), so... wtf, I'll try it.

I didn't use a CMC, as recommended, so I'll build one of those next and see if it makes a difference.  And find a location with less QRN/M.


Starting my vacation on Monday.  My plans to return to Lost Lake for FD went to shit, so I'm going to try setting up at a couple local places and see how things work.  Might try my first POTA activation, too.

Here's a helpful link on that style antenna. Also note the reference and link to the TC2M improved BBV design.

Cool, thanks!  Gives me something to read at work tonight.

That is really nice!

I know someone that uses a 135 foot endfed ( 80m HWEF ) and he tunes it to 160 and gets out fine. He is light compared to all the guys on 160 that have big amps, but we could talk.

You need a good counterpoise for efficiency but you dont want 1/4 WL on 160m counterpoise because that turns it into a dipole and the feedpoint will be close to 50 ohms and then the 49:1 unun will turn it into 1 ohm and that might be be tough to match.

You can use another 135 foot wire  and just jumper across the unun and have a dipole.



The problem this time of year is all the static crashes from lightning.

Thanks! Everything works, and nothing melted or caught fire. I put 20a fuses in the power pole out, but I wouldn't worry about putting a 25a for 50w SSB. I haven't tried, but I'm pretty sure I could swap out the battery with my 10ah Dakota
Lithium if needed.
I still need to add some "shelves" so I can use the space when taking it portable.

Not exactly my project but it was a very happy day for me -- I have random QRM on my radio, primarily
on weekends, that I strongly suspected was from a plasma TV. Since I live waaaay out in the boonies,
normally my noise floor is close to zero, so when I saw the QRM I figured it had to be one of the few
neighbors I have, most of whom only come up on weekends.

Today I got a call from a part-time neighbor for help lifting something he and his wife couldn't.

I get there and lo and behold, and the task at hand is removing an ancient Pioneer plasma TV
off their wall. Mystery solved, and one more massive QRM emitter is off the air!

Back to S0 noise for me.

Hah, that's a stroke of good luck!  I have a ton of noise on 40m, around S7.  No idea where it's coming from, but I haven't looked to hard either.  I'm just waiting for a day when I am home and my wife has taken the kids somewhere for a few hours, then I can hook up a battery and shut off the breakers and see if it's still there.

Humbled myself to accept Xubuntu is just too much for me to learn how to do certain things.

Loading Linux Mint on the Ham Laptop today, to see if things are a little easier to figure out.

I noticed wally world has some laptops on clearance, might snag one in a moment of weakness so i can have enough hard drive space for the full Andy's Ham Radio install.........

I use Mint.  You can easily get wsjtx, fldigi, gqrx running with sudo apt install 'xxxx'.

As mint is a fork of Ubuntu...and Xubuntu is just Ubuntu with XFDE instead of GNOME, you should be able to do that on either. I haven't messed with Mint since...2013, got on a Ubuntu binge after that then Ubuntu got spaced enough from Debian that it began creating some issues Debian just didn't have. Got into CentOS...then IBM shit-canned it so I went to the newly expanded developer program to get Red Hat. RHEL is still my go to in all honesty but I run a lot of Debian and Alpine.

Nice job!    I built one just like it in a PVC box using 3 stacked cores which was probably overkill but I do run QRO. Mine is outside on the output of the antenna switch so that every antenna is fed through it before entering the shack.

Man you are so lucky

Radio, but not ham radio...

The battery on my Pixel 3XL did the Scary Swollen Battery Thing. I'm trying to hold off on buying a new phone so I can get one of those bad-ass, Iridium-enabled phones when they come out in about a year. So off to Amazon I go to buy an $18 replacement battery. Then off to YouTube to see how to do it.

I set my fancy hot air workstation to 100C per the videos and had at it. As you can tell from the photo, removing glued-on, rear panels made out of glass is a next level skill So back to Amazon I went to get a $22 replacement. My panel removal mistake tripled the size of the task, as you have to melt more glue and move over the camera lens, flash diffuser, fingerprint scanner and NFC antenna, all of which have to be re-glued into place on the new panel.

I am now a cell phone glue melting expert Turning up my air to 130C, and using some heat resistant glove, really improved the process.

I've tested everything except the NFC, got to hit the store for that. So far, so good. I'm not touching the thing for 24 hours so the panel glue can fully setup. I hope I've re-achieved the IP67 qualities of the phone...

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Here is a comparison in the same half hour of a Horizontal 20m dipole at a height of 0.5-0.6 wavelength and a dipole hung from one end vertically to about 2 feet from the ground with the feed line at 90 deg from the antenna plane.

I expected at least a little difference.

Vertical
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Horizontal
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Reduce power until you see half the number of stations, then repeat the test. It might be a little more apparent.

I just went through doing A-B comparisons on 10M antennas and I had to put 20db of attentuation on the 200mw transmitter
and then force my receiver to fixed gain via the RF gain control to get reliable test results. Pretty much everything is
trying to get the signal through which makes comparisons really hard until you get into edge cases with very low
signal strength.

I recently picked up an older Samlex SEC-1223. It has a broken cooling fan and I haven't found an exact match as a replacement. I'm sure there are other options out there. Electronic repair isn't my cup of tea. I usually get other people to do it for me. This one seems simple if I can find a suitable fan. Attached File
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I can try that.  Both of the above were 25W

What would be the expected result with a verticle vs horiz dipole at those heights ?  Which would be expected to perform better?

0.5WL is respectably high for the dipole, but in general you'd expect the vertical to be more omnidirectional
and potentially show more DX, while the dipole should have more of a pattern -- but if your horizontal dipole was oriented
North/south (e.g. E/W is broadside) given the density of reporting stations is also E/W, you might not notice
the pattern so much.

If you were right at the limit of detection, I'd expect fewer reports on the vertical and a greater density of
reports on the horizontal dipole broadside to the orientation of the wire.

@Ohio_Sharkman

Search for 60x20mm fan12V

Can you zoom in and compare the signal reports for stations that received both antennas?

Great idea -- or better yet, using WSPR, look at the database view. I'm not sure what mode DarkLordVader's map is.

Using database view it should be possible to compute a median signal strength and compare the two
(as well as totals for each antenna.) The idea would be to alternate several times and then compare only
stations that heard both and compute from those.

I could definitely scrape the raw data from the PSK reporter and compare same-station signal reports.  I am using FT8 mode, since there are a lot of listeners/reporters at any time.  I will need to repeat the test, will do so when the rain breaks here.

{"receiverCallsign":"xxxxx","receiverLocator":"FL15GB","senderCallsign":"xxxxx","senderLocator":"xxxx","frequency":14075663,"flowStartSeconds":1687293702,"mode":"FT8","isSender":1,"receiverDXCC":"Bahamas","receiverDXCCCode":"C6","sNR":-13}

Thank you. One of the instrument techs at work does a lot of this kind of work. He said just bring it in and he will fix it. He thinks he already has a fan that will work.

I had plans for Field Day.

Had.

Doubt I'll even bother turning on the radio at this point.

We could do a 17m arfcom net portable.

I can hear the tube amps warming up already to mash the tune button.

What would be really cool is if you can use an azimuthal projection of the map centered on his QTH and filter for stations in 20 degree slices and maybe get an idea of comparative directivity based on the relative signal strength differences in different directions.

ETA if someone could automate this, it would make a great antenna comparison tool.  But I don't know enough about coding to make it happen. Which is to say, I don't know anything about coding.

I went to lowes and got a 1x12x72 and made a shelf for above my radio desk. Nice to get some stuff off the floor.