Summer's gone already

 Summertime is not a big operating time for me these days but as the weather gets cooler I start to think of antennas and what I need to do before the snow flies.  I had put up the doublet in the spring and it ran just touching the weeping willow tree because that was the path between my 2 supports.  The antenna got tangled up with the tree and I was not pleased with using the tuner each time I moved on the band or changed bands.  Some bands worked well and others not so much.  I decided to rethink my options.  I had put up an end fed wire for 40 and that was fine with the little tuner I built but I decided to drop it and put up a tuned dipole instead.  The end fed is a compromise and I wanted to do a fan dipole using the window line.  I made one with 40 on top and 17 underneath.  This antenna doesn't interfere with any trees and I reused my center support from the doublet making this antenna slightly inverted V-ish.  Now I have the 2 fan dipoles (20/30) and (17/40) and my EFHW for 80 which I am still not completely pleased with but I have it and will use it this winter.  It works and I make QSOs and that is what counts.

I plan on taking part in more NAQCC monthly sprints this winter and they use 20/40/80 which I now have covered.  I am not a contester but these are low pressure and I really enjoy having 2x QRP QSOs.  The days are getting cooler and my operating position (a lawn chair and card table in the barn next to the window) is ready for me.  The raccoons will soon be coming home to find winter homes and I hope to seal up their access to the barn but it is a challenge as they can be pretty crafty.  They stay on the second floor and don't bother my stuff but I'd rather not have them but that's what you get when you live rurally...that and the red squirrels.

I have  had a couple of QSOs this past weekend but I am still busy with other jobs and not had a lot of time to operate.  Soon enough, I hope.

Cheers es 72/73 -- Scott  

Doublet update

I finished the support post and here is a photo.  It keeps the center of the antenna at about 25' and out of the weeping willow branches.  The wire actually runs north-south.  I am looking south in this picture and the wire goes over that tree just to the left of the support that you can see in the distance.  The near end of the antenna goes over my head to my TV tower behind me.  I installed 2 guy ropes at the top of the 2nd 2x2 to give the antenna more stability because it gets extremely windy here.  It's surprising what you can throw together with what's on hand.  It was only a few hose clamps that I needed to get.

I am happy with the antenna except for 20M which I will install a dipole for.  Incidentally, last night before the support was installed I had a 40M DX QSO with Italy with 5W.  I was very pleased considering the conditions and the band.

Doublet Up and more to come

On Saturday I installed my doublet and the center hangs down to about 23' above the ground.  It's heavy over a long run so it does sag some.  I have decided to prepare my center support to take some of the load off and also to provide me with another use.  More on that later.

I tested my doublet with my tuner and found a very good match on 40, 17 and 15 and a reasonable match on 30, 12 and 10.  I could not match on 20M.  I made some contacts and was pleased with the flexibility I now have across the bands...except 20M.  I thought the issue was the length of my feedline so I trimmed 8' from it and still it behaved about the same.  Someone suggested that the length of the antenna may need some trimming.    I lowered the antenna and trimmed 2' off each end and raised it back up again.  The bands that were reasonable improved slightly in the SWR department but 20M stayed unacceptable.  Rather than fart around with this doublet to get something "reasonable" at the expense of the other bands I decided that I would prefer a tuned antenna for 20M so that I can get back to doing some QRPp work eventually.  I have decided to make a single 20M dipole and support it from the antenna support I plan to install.

In the QRP tradition I want this support to do the job with low expense and also with what I have on hand which is challenging.  I have wood.  I have a patio umbrella stand that anchors with patio stones in the NPM (non-penetrating mount) fashion since I'm not quite ready to dig and bury a 6"x6" or 4"x4" post as a base anchor point just yet.  I have a pulley and I have a 20' fiberglass Wonderpole with the tip broken off.  Originally I was going to use just the top section of this rod as I explained I was going to do in my post Still a Bit Chilly but I have changed my plan a bit to use the whole thing.  The only thing I am missing to get this support up are some hose clamps and some paracord.  I used up all the cord I had on the weekend so I will place an order at the local hardware store for a curbside pickup.

I am using two eight foot 2x2s end to end for the support and then I will strap the Wonderpole to it at the top.  This will give me close to 30' of support.  I may be able to get away with no guys at all, since the Wonderpole is light.   Just below the doublet I will attach a pulley and install a dipole for 20M.  The paracord attached to the legs will give me some added support.  Joining the 2 wood 2x2s end to end is a challenge and here is what I have come up with.

I ripped some 1x8 down to about 2" wide which is the same width as the main support pieces. the pieces are about 2' long.  I sandwich the support pieces at the joints and secured with some screws, wire and hose clamps.  The photos show wire I used but this won't be strong enough.  I don't have any fencing wire or I would use that and hose clamps are easily removed and adjusted.

I have strapped the support pole to the umbrella stand and will add the Wonderpole to it hopefully today,

More to come
Cheers de Scott ve3vvf

Little Tuner Helpful

When I built the QRPGuys Multi Z tuner it was so I could use it with the Doublet I plan to put up (once I get a launching method) but then I thought I'd give it a try with my random wire since the Doublet isn't quite there yet.  The random wire is about 125' long, I believe,  and works very well on 30M but that's about it.  I hooked the little unit up via a short run of Co-ax to my LDG 9:1 Unun and I was able to tune it quite well on 20M and on 17M.  40M was not so agreeable and I didn't try 12 or 15 but if I were going to use this antenna and tuner together regularly some adjustments to the wire length would likely be required.  I tuned around 20 for a while and there was a lot of activity and I was getting a little over-zealous trying to reach a Brazilian station and also a few other DX stations but I really should have known better and stuck with something more domestic.  As it was, my battery was down to 10-11v and I knew my FT-817 wasn't even putting out close to 5 watts into a non resonant antenna...during poor conditions.   All that being said I was happy with the tuner and how easy it was to operate by tuning to dim the tuning LED.  As the LED gets dimmer your match is better.  It was super handy and I think I am going to enjoy using it.  Tonight I'll charge my battery and test it again on more bands on the next nice day.

Still a bit chilly...

I went out with full intention of getting this antenna going.  After I put sheets on the clothesline my hands were already chilly.  What I decided to do was start fiddling with my support pole idea.  My plan is to make a pole by connecting 2"x2" pressure treated end to end until I reach the height I need to sufficiently support the center of the doublet.  Because it will be guyed I am not too concerned about strength.  What I will do is place four twelve inch 1"x2" around each joint to provide support.  It won't be pretty but should do the job.  I will guy the pole at the top and again at some midway point.

My biggest dilemma was what to do at the top to hold the antenna in place while still providing for some up and down movement as the antenna flexes with the wind in the trees.  In the barn I found a 3' fiberglass section from a 20' Shakespeare Wonderpole fishing pole that I used to use for portable dipole setups at parks.  The tip had broken off when I dropped it from the second story roof peak one time (on purpose...I thought it would land flat but it didn't).  Anyway, I plan to drill a 1/2" hole in the top end of the top 2x2 section and glue it in place.  I also drilled a 1/2" hole in the top of the plumbing T so it will slide over top and sit on the top of the pole.  The photos below of my plan explain this better than my words can.  I just did this in a scrap of wood to prove to myself that it should work.

The T is able to slide up and down on the fiberglass shaft by as much as 2'6" and I will put something on the tip of the fiberglass shaft to prevent the T from sliding up and off the top completely in strong winds.  Now I need to investigate what length of pressure treated 2x2 I can get (10', 14'...16') because I'd prefer not to use 8' lengths so I can have as few joints as possible in the mast.

The other thing I did was measure out the antenna wires on the ground at 73' each.  I left them on the ground for now and called it a morning.  If it warms up I will go out and solder the center connections.  I can make and put the antenna up without the support pole.  The pole is just an addition I will install to steady the antenna in the wind I will inevitably get here in farm country.  I am also still trying to figure out how I will get the para cord over the top of the 60' tree.

Cheers for now,
72/73 de Scott

Doublet length

So I had decided to install the 40m (and higher) doublet to save on weight even though I had the space for the 80M doublet.  My original thinking was that some day it might be neat to compare the EFHW 80M antenna with the 80M doublet since my QRP Guys tuner that I plan to use with the doublet does not support 80M.  Then I read that a doublet will actually provide better performance on a given band if the antenna were resonant on odd harmonics for that band so I thought that since the doublet length is not critical I could play with the length to give a boost to a favourite band.  I knew there are websites out there that will calculate this for you so I went searching.

I looked at a couple and then found this page on Spookmate.com.  I was able to put in the frequency for 80M in the calculator and see what my options were.

As you can see where the harmonics are listed that 10.5 is the 3rd harmonic.  This is very close to 10.110 where I like to operate on 30M.  I then adjusted the frequency at the top until the 3rd harmonic was where I wanted it to be.  3.37 MHz does the job and the legs of the doublet would be 72.9' long.  The key with the doublet is that the antenna is not resonant on 80M if I want to use 80M.  It is not (although it may be too close) but I am not using the antenna on 80M so I'm not concerned about that.  Really I'm taking advantage of the 3rd harmonic which I would not have if I were to put up the 40M doublet.

The harmonic frequencies gave me no joy for the 17M band which I also enjoy so I will go with the 73' length.  This is what I plan to experiment with when I put this doublet up, hopefully this weekend, weather permitting.  I'm not sure how much luck nor do I have a way to get tangible results but my random wire is currently working well on 30M only so I can compare the two.

Now you may remember I was going to avoid the 80M doublet because of weight concerns but I have come up with a plan for a guyed wooden support pole.  It'll be a little "interesting" looking but I think it should do the trick.  I'm fine tuning my idea in my head daily and am almost there.

Cheers for now,

72/73 de Scott

Doublet Dilemmas

When it comes to installing my, yet-to-be-built, Doublet antenna my biggest concern is weight and whether it will need a center support.  If it does need a center support what will I use and how strong will it be?  My original intention was to install an 80M doublet just because I have the space but that antenna will be significantly heavier than one for 40M.  The QRP Guys Multi Z Tuner that I just completed only tunes 10-40 so an 80M doublet is definitely overkill so it only makes sense to only put up what I will need in the immediate future.  As well, I have my random wire that will be modified to be my 80M antenna with the addition of the QRP Guys EFHW mini-tuner kit for 80M.  Once these projects are ready to test I will do so using my FT-817.

Here is the image from the QRP Guys website:

If I still need support for the doublet I have a couple of options I've been contemplating.  I could use a guyed wooden support made from pressure treated 2" x 2" or I could use a guyed PVC water pipe mast with about the same 2" diameter.  I live in a windy location but the center of the doublet will be somewhat shielded from the wind by my small barn but I still worry about it.  The wind on the antenna wire is not my concern as much as the window feedline is.  It is both heavy and easily caught by the wind.  Only putting it up will tell how these factors play out in real life.  The height this antenna will be remains unclear but I am hoping around 40' up.  One end support is the 40 foot TV tower attached to my house and the other end is a tree over which the para cord will be tossed so the actual height of that end support remains to be seen.

The center of the antenna, since I am unable to 3D print at the library is going to be something I have used before for dipoles, although this one is a bit larger.  It is a PVC water line "T".  It's durable and lightweight and I can easily drill or melt holes for the wires to pass through :

Cheers for now,
72/73 de Scott

QRP Guys Multi Z Tuner completed

Carrying over from yesterday the last thing I had to do with the tuner construction was to wind and install the transformer.  There are 3 windings on this transformer: a primary with a center tap and 2 secondary windings of different sizes.  I wound it all up once but it was too sloppy so I removed all the windings and made it a lot tidier and tighter.  Below are the 3 stages of installing the first, second and third windings.

 Once that was wound I had to ensure all the enamel was off the leads and tin them.  I then fed them through the appropriate holes.  When I did this the first time I saw that there was some enamel still not scraped off so I pulled it back off the board and did a better job of stripping the enamel with the Xacto knife.  I then reinstalled it in the holes and soldered them in place.

Now the final touch was to install the PCB washer to hold the transformer in place and put the rubber feet on the back.

I have also included the circuit design which is also available in the assembly instructions on the Multi Z Tuner page on the QRP Guys' website.  

My next step now is to build my doublet and get it up in the air.  That will be happening in the next week or 2 weather permitting.

Cheers for now,

72/73 de Scott 

QRP Guys Multi Z Tuner started

I got down to making the QRP Guys Multi Z Tuner 10-40 this evening.  The first thing I noticed was that my eyes really aren't what they used to be.  Even with glasses on I could have really done with a pair of these:

                                  or this    


My ageing eyes aside, I dove in and got started.  The project does not have a lot of components so the construction isn't too difficult however there are some challenging bits to keep you on the ball but the instructions are top notch.  The first step is joining some PCB pieces together with solder to create the "chassis".  Once complete I began installing parts per the checklist:

Aside from the standard components there is a small toroid to be wound with a center tap.  This went fine.  It's been a while but it all came back pretty quickly.

By the end of the evening I had everything together except for the most challenging part, the large transformer.  For that I will wait until my eyes aren't tired and there is some natural light.  Here is the finished product for this evening.

Back at it tomorrow.  Cheers es 72/73 de Scott

During these times...Projects

With everyone pretty much stuck at home in isolation it's a great opportunity to think of antenna projects and other things like that.  I installed a random wire antenna last fall but with my Z11 tuner is not tuning it at all (I'm not sure if it's broken or just a bad setup) I can only operate it on 30M which is fine by me as it's one of my favourite bands.  That being said, i ordered 2 little kits from QRP Guys.  The first kit was the EFHW Mini tuner.  There are 2 versions to choose from and I chose the 80M version.  This little rig will hopefully help me turn that random wire antenna into a dedicated 80M EF antenna.  I will have to lower it down and add about 10 feet of wire to get to the recommended 135' starting point.  The below photo is from their site.

The second kit I purchased was for the Multi Z Tuner 10-40.  My plan with this little gem is to use it with the doublet I plan to install over the coming weeks.  I have the wire and space to install up to an 80M doublet and I figure I might as well go that route even though this tuner will only help down to 40M.  This kit is a bit more involved but shouldn't be too bad since there are no SMT components involved.  Here is the photo from their website:

A few years back I bought a good length of 450 ohm window line for a project that never came to fruition so now I can use it for this.  I have heard a lot about these antennas and the multi-band properties make it attractive.  I've always been one for using tuned dipoles but in my windy location they are a challenge to maintain.

I did have a plan to have the center support insulator 3D printed.  I found a nice one on  Thingiverse but the local library, which has the printer, is closed until further notice so I may just have to fashion one up.

I will post my progress with the Multi Z Tuner as I tackle that kit first.

Cheers es 72/73

Scott