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.

Antenna Launch Success

I lowered my random wire antenna this week so that I could make the length a little less random.  I added 8' to it to help avoid half wavelengths on multiple bands by using a chart I found on this website.  The chart at the bottom shows you the wire lengths to avoid depending on which bands you plan to use.  You can visit the page for an explanation of the chart but basically you want to choose a length where the fewest amount of colour bars are present.  I chose somewhere just above 135'.

I lowered the antenna and added the length of wire to it and I was hoping to get it anchored higher in the tree with the newly purchased fishing reel and slingshot from Canadian Tire (Curbside pickup, of course) so I let the support rope come all the way down.  Bad Idea.  I was quite disappointed at the lack of punch this slingshot gave me.  The wind was also working against me.  I tried a few times and from a few different angles but it just wasn't working.  What I ended up doing was using the fishing reel attached to a screwdriver stuck in the ground (thanks Michael, ve3wmb) aimed at the tree top and I created a sling with a piece of broken brick and 6' of para cord.  I tied the fishing line to the brick also and then I rapidly started spinning the rock in an overhand fashion (think David and Goliath) and let the rope go at just the right time for it to sail towards the top of the tree taking the end of the fishing line with it.  This really did the trick.  It took a few tries before I was happy with the placement and height but once it was there I let the weight of the brick bring it to ground level where I detached the brick from the fishing line and tied a new rope to the fishing line and pulled it back up the tree and over the branch and down to me.  I wrapped some tape around it to help keep it from getting snagged in a notch or branch. I could then attach the antenna to it.  I pulled it up using the antenna rope and it was perfect.  I was very happy.  I seemingly bought a slingshot for nothing but you just never know.



Once my Random wire was back up it was time to get the rope in place for the doublet I plan to put up on Saturday.  Now that I had the method down pat it only took 2 tries to get the fishing line over the top of the tree my doublet support rope will be draped over.  Now on Saturday (tomorrow) I will lower the random wire because the doublet will pass over top of the low end of the random wire.  I'll attach the other support end of the doublet to my TV tower at 40' and once up I can raise the random wire again and I will have 2 antennas up...an all band doublet that I will use from 10-40M and an 80M end fed once I get the final toroid from QRPGuys in the mail, whenever that is.

I'm excited to try this doublet fed with balanced window line and the QRPGuys MultiZ tuner.  I'm hoping for a better match than I was getting on the random wire.  I will know tomorrow and there is also the QRPTTF (To The Field) "contest" all day tomorrow.  I say "contest" with quotes because it's low pressure which is right up my alley.  The theme this year is OPERATE FROM HOME.  Do not go out to parks etc but just go out in the yard instead because of the COVID-19 isolation rules currently in place.

That's all for now,
Cheers es 72/73

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

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