Radial Daze

Messed around with the radials today. I pulled them off the fence, and coiled them up to 25', and saw the VSWR curves improve. I kept doing it until I couldn't reach any higher to cut them, and they wound up being about 6'~7' long, hanging straight down from the ground connection (coax shield), and tie wrapped to the mast.

This might be "as good as it gets" with this antenna, in this installation. The BuddiStick still works better on 20 Meters, so I'm hoping the CommTek 20 Meter aluminum tubing vertical will be as good.

This isn't 100% usable with the FT-1000D, as the VSWR in the 75 Meter band (3.5~4.0MHz) is still outside of the range the radio.  

And I'm feeling somewhat better, but still sneezing with a very runny nose.....

Cloudy, Rainy, Dreary Day in Northern Colorado

And I have a cold on top of it, so that means no outside antenna work today.

Raising the center support from ~15' up to ~25' had very little effect, so my Wire Antenna Guru first thought I needed a "Common Mode Choke" on the feedline. These can be as simple as a number of turns of the coax feedline coiled up, or you can use a ferrite toroid core, and wrap the coax through that. Sine I already have a Balun Designs "Line Isolator", I went ahead and tried that. It made a slight improvement at the low end of the frequency range, but wasn't a Magic Bullet, so I took it back out.

The company that makes this antenna claims it will work without a counterpoise, but the coax needs to be at least 25' long. This is a huge red flag to me, because it means they're using the feedline as part of the antenna, and I've always read and been taught that you don't do that. It's a Kludge, and generally leads to poorly reproducible results. As in change the orientation of the coax, and your antenna no longer "works".

And they're pretty cagey in describing the use of a counterpoise:

"It could work without counterpoise (Coaxial cable has to be at least 25feet long) but grounding at wingnut next to connector is recommended."

And:

"Due to possible common mode currents on your feeder, we recommend using CMC-Common Mode Choke/Line isolator such as CMC-154-3K to keep RF away from you and your equipment. It will also help you on receive by filtering induced noise from various sources."

Hence my Guru's recommendation to try the choke.

Hmmmm.....On to "Grounding"? How? Run a #10 wire down to a good old "8' Ground Rod"?

Anywhoo.....It's an antenna, and it requires some kind of ground to work against. If not a properly engineered Ground System", which is basically as direct a connection as possible to Mother Earth, than it needs an "Artificial Ground", generally referred to as a Counterpoise. I've used the term many times before, and it's important to understand that pretty much any antenna other than a dipole must have a ground. In a dipole, one half of the antenna serves as the "ground" for the other half. It's "self contained" in a way, and doesn't require a separate ground.

Anywhoo (reprise)......Since the manufacturer is so vague, it looks like I'll have to explore playing with the counterpoise wires I have. My Guru now thinks they're too long, and I might only need a single one. After it dries out some and I'm feeling better, I'll get out there and start modifying what I installed. It's very easy to temporarily shorten them by coiling them up, so that's where I'll start.

At this point, since I now have the center point at 25', I'm musing about just putting up a 40 Meter (66' long) dipole......

End Fed Antenna Project - Fettlin', Fiddlin', Tinkerin', and Piddle Fartin'!

Been a busy week here on the radio scene. I really want to get this "Mark-I" version finished up, as the weather is getting seriously nice, and I have to get cranked up on Ms. Swan again.

Anyway.....I raised the center point of the antenna today, going from ~15' up to ~25' or thereabouts. My Great Plan was to bore a 1-1/4" hole in the top of the trunk, and drive two pieces of mast into it. That plan failed when I borrowed my neighbor's 17' ladder, and went up to the top of the tree and looked around. Uhhhh......NO, I'm not going to be fighting with a Heavy Duty 1/2" corded drill mounting a 1-1/4" auger bit in it while trying to maintain my balance (and sanity) while perched atop a 17' ladder. No sir, don't like it at all!

So I dropped back and thought about while I did some other things with the antenna. In reading some 50+ year old Amateur Radio publications, I discovered (REdiscovered?) how the Old Timers did it.

They bolted a 2x4 to their trees, giving them a flat surface to mount things to. Brilliant!

So since I had a 21" piece of clear cedar 2x4, I laid out a hole pattern, drilled some pilot holes in it, and proceeded to screw it to the tree with these really nasty 5" long SPAX construction screws. This is a 3" version, and even though they proudly proclaim "NO Predrilling! NO Splitting!", I still don't trust them, so I drilled 3/16" pilot holes through the cedar 2x4.

And after much huffing, puffing, and ladder moving, I now have a 10' mast very securely screwed into the side of the tree.

The cedar board is held in place with 7 of the SPAX screws. I drilled 8 pilot holes, but the last screw was giving me a lot of grief hitting the mast, so I left it out. These screws go through the 2x4, an inch and a half of bark, and then into the tree. Some back-of-the-envelope SWAGS indicate I've got the sunk 3" into the core of the tree, and I surrendered and went with 7.

The saddles that bolt the mast to the board are also held in with eight, 6" SPAX screws, so I really have fifteen points of attachment sunk 3" or so into the tree.

Yeah, I think it'll hold.

There's not much load on it at all, and wonder-of-wonders, looking at it from several locations ~90* apart, it's PLUMB!

How the *(&^^ that happened is beyond me. I put one screw in fairly tight, and then used a level to get the board plumb, and drove in another screw to tie it down. The level still indicated I was OK, so I blasted the rest of the screws into it, and ran up the mast!

And for Brig, here's the crabapple in bloom. I'll take another one when the light is better, as it's a very pretty tree. First "pretty" tree I've ever taken care of. I've tended maples, and they're gorgeous in the Fall, but this one really makes me appreciate Spring.

And on the bench, we have a little item I tinkered together. It's a "Feedpoint Interface Box", and nothin' special.

Just an SO-239 Type UHF female socket, and three attachment studs made using 10-32x1" screws, nuts, and washers. This is just a fancy way of going from coaxial cable to wire. The center conductor of the coax runs to the top, while the shield of the coax goes to two attachment points on the sides. The top terminal will connect to the 16-1/2' aluminum vertical I have partially assembled in the garage, while the two side terminals will each connect to a 16-1/2' long radial wire forming the counterpoise for the vertical radiator. Since the radiator will be about 6' above the ground, I'll just staple the two radials to the fence, and they'll be far enough above the ground to be "Elevated Radials", which I means I can "get away with" using only two. Three or four would be somewhat better, but two is enough as long as they're several feet above the ground. In essence, what I'm doing is making a more rugged, permanent version of my BuddiStick 20 Meter quarter-wave vertical antenna.

I've lost track of the number of times I just soldered the wires directly on the coax, wrapped it up with half a roll of tape, and hoisted it up into a tree. And they work just fine, thank you. Not super weather proof, but if you need an HF antenna NOW, they're perfect.

And I made some back-up plates for the outdoor entrance box, and the matching box inside the house. I don't like just screwing bulkhead feedthrough connectors directly into a plastic box. At a minimum, you need some big washers to help spread the unexpected side loads the connectors will suffer when somebody bashes into the connector. And when things like this are located outside, it will happen. So rather than having the connector(s) rip out of the box, I made some aluminum plates from some cheap stock I grabbed at Home Depot.

The plastic box is sandwiched between the two aluminum plates, which spread any loads out over a much larger area than what the thin hex nut holding the connector in the box does.

And here they are installed and sealed in the outdoor entrance box.

Notice the very large "Fender Washer" used on the other connector. These things are works of art, and they're much more a "Machined Spacer" than a humble "Fender Washer". They were also EIGHT BUCKS each! In retrospect I should have just bought the flat stock at Home Depot, but.....

The fettlin' part comes because there was some, uh....."drift" in the measurement/layout process that caused the holes in the box to be 1-1/2" apart, but the holes I made in the flat plates were something like 1-7/16" apart, causing me to "fettle" on the holes in the box with a rat tail file until all the pieces fit properly. Oh, well, the plates cover up the ovaled out holes in the box nicely.

And I still don't believe I got the mast plumb.....

30* and Snowing

Quite a change from yesterday's 74 and sunny!

It started snowing here around 1100, and when the grandson came downstairs from his nap, he looked out the window and said "SNOOOOOW!!!".

Glad I put plastic buckets over the new plants yesterday. Hopefully the buckets will provide some protection for the little plants. I suggested to my wife that maybe she should wait until after Mother's Day to plant, like everyone else here does, and she replied "Oh, Winter's OVER! We won't have any more snow".

Famous last words.....

Have a good week, wherever you are.

Sunday Morning "Excitment".....

Not sure what else to call it when you see a brigade of firetrucks screaming into your neighborhood...

My wife wondered what all the fire trucks were doing, so since she twisted her knee, I turned on my scanner and walked down the street.

There were five fire trucks, three Suburbans, two ambulances,, and firemen everywhere. The house had ladders up to the second story on three sides of the house, and firemen were scrambling up and down them with hoses, axes, and other fire fighting tools.

The scanner locked on to the Poudre Fire Authority channel, and I found out one of their solar panels failed, caught fire, and set the roof on fire. Our neighbor's kids right across the street were outside playing in their backyard, saw the smoke, told their Mom, who called the homeowners, who looked outside and immediately dialed 911.

Seeing that Fire Station #4 is less than a mile away, I'm sure they were here PRONTO.

From what I heard on the scanner, the fire was contained to just the roof, and burned a hole about 6"x12" through the roof. The firemen reported very minor smoke and water damage to the attic and ceiling, and they used big fans to clear the house.

So no major damage, NO injuries, and kudos to the kids who spotted it, and told their Mom, who called the neighbors.

And three cheers to the Poudre Fire Authority for their rapid response, and excellent job in striking the fire.

Car Audio/Nav Update

Well, after soldering up the new harness, I got ready to install the radio this morning, but had a few checks to make before I went ahead and screwed it into the dashboard.

But let me back up and fill you in on what happened.

A month or so ago I went to a Hagerty Driver's Club event at the Scuderia Rampante in Erie, Colorado. The morning was cold, and the car radio was being really wonky about playing anything from the USB stick, and when I pulled the stick out of the socket, the radio reset, and then shut down ( ! ), causing me to have to pull off the road and try to get it going again. It finally turned on, but just sat there mute, so I sighed and continued on my trip. Sometime later it finished booting up, and started to work normally. Then the day we went to DIA to pick up my wife's friend, I started the car, and NO radio. Nothing.

Checked all the fuses, pulled the unit from the dash and reseated all the connectors and nada. So I coughed up the $$ for a demo unit that was a floor display at a stereo place. And of course, none of the connectors are the same, so down to the basement to make things match up. I also corrected some (*GASP!*) wiring and installation errors that I'd made during the original installation. I was bypassing the OEM 80W/channel amplifier, and I had a couple of speaker wires crossed up, so the new harness has been triple checked.

Last night I got out a power supply, and connected the old radio and the new radio to see if I could power them up. The new radio was very poorly packed, and I had doubts if it survived the trip, so I wanted to check it out. I connected the old radio first, and damn....it powered up just fine! Must be a problem with the car, then. The radio had the blinking 'standby' light before, indicating it was getting "12 Volts, Always On" which retains the memory, but was 'dead' when you tried to power it up. The signs pointed to either a bad fuse (there are two for the radio), a bad connection, or a bad wire. The new radio also powered up just fine and checked out, so at least I had two known, "good" radios.

This morning I checked all the fuses again, going so far as to remove them, visually inspect them, and continuity check them with my Ohmmeter. All were fine. So I shot the dice, and continued with the installation. Then I disconnected the battery and waited the prerequisite 15 minutes for the "System Capacitor" to discharge, and took the airbag off the steering wheel. I had to do this to replace the two back-of-wheel switches that control the radio, one of which failed a couple of years ago. It would only tune the radio going down in frequency, instead of tuning both ways, but it worked so I let it slide. When I bought the replacement switch for the left side (tuning control) I also bought one for the right side (volume up/down), so since I had it apart, I replaced both of them.

Then I neatened up the bundle of wires on the back of the new radio, and installed it in the dash. Reconnected the battery, and wonder of wonders, it worked! At this point all I can think of is that disconnecting the battery for a couple of hours reset something in a Power Control Module somewhere, or perhaps just pulling and reinserting the fuses did it. All the fuses were in physically excellent condition, and had silicone grease on the contact blades. The Jeep forums have mentioned disconnecting the battery to cure a variety of ills in the WK series of Grand Cherokees, with great success, so maybe that was it.

So it's a mystery for now, but it works, and I have a radio and navigation system again.

AND a nice, clean, used Kenwood DNX771HD to put on eBay.....

First World Problems.....

OMG!! My car stereo/navigation unit died! It's so UNFAIR! How will I get to my pilates class without soothing music-to-drive-by? How will I find my around without my GPS!?!

OH, THE HUMANITY!

Yeah, my damn Kenwood took a dump and went casters up. And of course, the replacement unit has a different connector, so I yanked everything out of the dash the other day, and took my custom wiring harness down to the basement, cut it apart, and I'm busy getting the harness for the new radio integrated into my existing harness. The reason it's a little more complicated than just swapping out the radio is that I have a little iDatalink Maestro unit between the radio and the vehicle wiring harness. The little box lets me use my steering wheel controls to run the radio so I don't have to reach over and tap the screen icons to do things like change the volume, or tune to a different station.

My wife keeps telling me how well I'm taking these little setbacks, like having to fix the car, the mis-steps and side tracks of getting a 'permanent' antenna up, and a host of other things.

All I have to do is look at her, the house, the neighborhood, and the dog, and realize how blessed we are to live here, and I just smile.

"First World Problems", indeed.....

44* and Drizzling.....

Which is slightly better than yesterday, when it was 44* and raining.

So it's a good day to stay inside (no antenna work), hang out with the dog, and not do much of anything.

Had a wonderful Easter Sunday, with all the clan gathered, the BBQ cranking away cooking some carnitas my stepson marinated for a couple of days, and all The Little Ones running around in this big place doing kid stuff and looking for all the hidden "Easter Eggs" with little goodies hidden inside.

Tired kiddies at the end of The Great Hunt.....

Seeing these three going about their 'kid business' is it's own Celebration of Life, and a reminder that even after all us Old Fogies pass on, there will be others to carry the flame for us, as long as we raise them right.

And I think I'll brew up another cuppa, and head down to the workshop to tinker away what's left of this gloomy, drizzly day.

The Raising of the Feedpoint

Kind of appropriate that I'm talking about "Raising" things on Holy Saturday.....

We'll be having The Clan and The Little Ones tomorrow for Easter, so probably no blogging until late Sunday night.

Since a Golden Rule of antennas is to Get Them As High As You Can, I spent some time today adding another section of mast, and sliding the balun assembly up towards the top of the mast, eliminating most of the downlead from the wire to the balun. This raised the feedpoint (where the antenna starts) from about 6', up to about 14'. When the new post gets planted, I'll move these three sections of mast to the new pole, raising the top of the mast to about 20'.

I don't know if eliminating ~3' of downlead does much, but it lets me get almost all of the wire stretched out in a straight line.

And I even ran the counterpoise radials straighter this time.

By the time the "final" version of this gets on-the-air, I should be quite good at it!

This today's plot:

And this is before I raised the feedpoint:

And I ordered some slide together aluminum tubing and a mount from DX Engineering. I'll be building a 'permanent' version of the 20 Meter vertical to mount to the fence, so I can clean up and stow my BuddiStick and tripod back in their bags.

Hope you all have a very happy and Blessed Easter!

"Mark-I" 88' Wire Antenna Improvements

Spent the last two days "Prunin' and Tunin'" on this spin of the antenna, and I think it's about as good as it's going to get.

After looking at the data I collected, and seeing what was going on, I decided to go back to the full 88' length. This gives away some of the nice match it had on 15 Meters (21MHz), but improved it on 20 Meters (14MHz). The match on 40 Meters (7MHz) and 75 Meters (3.5MHz) is still far enough from 50 Ohms that I don't think I'll be able to transmit into it with this radio, but I can live with that for now. The final spin of this antenna will have an autocoupler at the feedpoint, providing a nice 50 Ohm match on all frequencies I intend to use. But for now, I'm getting my feet wet (again) with wire antennas of the non-resonant type. The only other time I've done this, has been with an autocoupler at the feedpoint, and since the radio always saw 50 Ohms, and I didn't own a graphical antenna analyzer, I couldn't measure what the wire by itself looked like, so I didn't care about it. I just put up as much wire as high as I could, and connected it to the SGC-230 autocoupler. So this has been an interesting learning experience, and a good source of exercise the last few days.

Final configuration for the "Mark-I" is:

88' wire, #14 gauge

9:1 balun at feedpoint

4 counterpoise/radial wires. Two are 100' long and six feet above the ground, and two are 50' long, about 2'~3' above the ground. The top ones are mounted to the fence pickets by threading them around every 5th picket or so, and the lower ones in the back run along the mid-height fence stringer, and the North ones are stapled to the fence. Going from two, 50' radials to four 50' radials, and then lengthening the top ones to 100' didn't change the shape of the curve very much, but dropped the curve down, resulting in a better match over the entire frequency range.

Here's the graph of the 'final' Mark-I version.

This would be a very good antenna to use with my little Elecraft K2, as the Elecraft KAT-100 "tuner" can easily match up to a 10:1 mismatch. The big Yaesu can only handle 3:1, so I'm stuck on 20 Meters and above.

For now.....

88' "Mark-I" Antenna Swept Measurements

Now that the wife's friend has returned to SoCal, I can *really* jump back into this wire antenna project.

As I noted last night, this thing has "ears", especially below 20 Meters (14MHz), which is going to be very useful during the Sunspot minimum that's going on right now. And it's also quieter than the vertical ("Vertical Antennas Pick Up More Noise"), which gives me some S/N ratio improvement, always a Good Thing.

This is a sweep of the antenna's VSWR from 3.5MHz to 28.550MHz at the OEM 88' length.

And this is a sweep with the length reduced to 84'.

They look very similar, but notice that the "peaks and valleys" have all moved to the right. This is consistent with a shorter length wire even though this is not a resonant antenna.

The blue vertical lines correspond to the frequencies of the US Amateur Radio bands, which is where I'm allowed to transmit. The left vertical scale is "VSWR", a ratio of applied ("Forward") power to reflected ("Reverse") power, an indication of how well the load is matched to the source. Please observe that this plot has nothing to do with where this antenna resonates. All this plot does is indicate how this antenna compares to a 50 Ohm matched load. A Dummy Load (sometimes called a "Dummy Antenna") would have a perfect 1:1 match from "DC-to-Daylight", and would appear as a flat line on the graph.

Here's what one of my dummy loads looks like:

See the green line at the bottom? VERY low VSWR, indicating an excellent impedance  match, which is why Dummy Loads are very useful for test purposes.

I'm not a guy who obsesses over getting the mythical 1:1 match. It never happens in the real world anyway, except maybe at ONE frequency, so it's not Real World to do that. I'm concerned with the areas below the 3:1 line, and what those frequencies are. This  transmitter will not function properly with a mismatch greater than a bit over 3:1, and dials the power back to a few watts to protect itself. Anything I can do to make the mismatch lower than 3:1 in the frequency bands I use (the blue vertical bars), is a truly great and wondrous thing.

So I futzed around all day shortening the antenna, adding two more counterpoise wires, making measurements and then doubling the length to 100' on the top two counterpoise wires, and taking the measurements again. Had to lengthen the rope at the far end, as shortening the antenna means a longer support rope, and I want enough rope to have the antenna completely slack on the ground, with another 10'. WELL.....as I was getting ready to tie on some more rope, I let got of the existing rope without having the free end tied off. Faster than I could catch it, the antenna dropped the rest of the way to the ground, pulling the support rope completely out of the pulley, and I watched the loose end of it fall to Earth.

GROAN.....had to drop the mast to rethread a new longer rope through the pulley, wasting a bunch of time due to my oversight about using enough rope the other day when I put this up. Oh, well.....beautiful day outside to do this stuff, and dog and I spent time playing ball and chasing wires and the errant squirrel around the yard.

I'll do a "Round 2" post detailing some changes I made today that improved things a bit. I think I see what's happening with the changes I made, and they're right in line with what I know about antennas.

But it looks like 75 Meters (3.5MHz) and 40 Meters (7MHz) will remain out of reach with this configuration, and this tuner in this radio.

Which is precisely why I need to get the SGC autocoupler mounted at the feedpoint.