14Mhz OP-DES Yagi Cont'd

Built and in the air, time to test the antenna with my MFJ259 antenna analyser.

Innov states 1.5:1 or better, well it is better, 1.1:1 across the whole of the 14Mhz band. cant get better than that.

for comparison I still have my cushcraft A3S antenna on another tower.
for the OP-DES yagi I ran 90meters of Messi & Paloni coax Ultraflex 10.  at 14mhz they state a loss of 1.4db per 100meters. if I had used RG213 then the loss would have been more than double of the messi and paloni coax. money does buy a db or two.

the tests I have done are not scientific but switching antennas and seeing what the S-meter says on my transceiver, K3S.
the OP-DES yagi out performs the A3S and the further away the station is the better it gets.
up to an S point or two better at times.
the front to back is amazing, upto 30db 5 S-points and the side rejection is also excellent.

one thing I have noticed from the A3S is, how quiet the OP-DES yagi is on Receive, upto an S point better. on a couple of occasions I cannot hear the station on the A3S but I could hear it on the OP-DES yagi.

Innov Antennas OP-DES

i recently brought an Innov Antennas OP-DES 14MHZ four element yagi with an 8.2Mtr boom.
OP-DES YAGI

fairly straight forward to put together, but i had to email Innov for a build sheet for element lenghts.

all tubing is aluminum, boom is aluminum square box, stainless tube clamps and nuts and bolts.
element placings along the boom are predrilled, but i did check to make sure i had them correct.

there is some theory behind the OP-DES design, ends of the driven element are bent 90degres towards the reflector. ill let justin tell you what its all about OP-DES THEORY

once i had the parts iddentified and placed on the floor it was just a matter of putting it together.

below, boom with start of elements

some more photos from my antenna build. As you can see it comes very well packaged.

All parts seperated and laid out on the floor.

First tubing added.

close up of the boom to element mounting detail.

driven element

boom jointing detail.

close up of the element clamping

end of the bent driven element. its insulated from the reflector. The insulator also adds support to the end of the driven element.

 

 

picture below shows a nearly finished yagi on a saw horse.

 

 

Finally built and on the tower.

 

more to follow.

 

 

 

 

 

Towermate

Towermate is a new design for your mast. it is a tilt plate that when you luff over your tower or mast the ariel stays parralel to the ground. this is good for easy maintanance, adjustment of yagis. more so when in high wind, just luff over and your antenna is about 6ft over ground.

it's locking device is automatic once up and in the vertical postion. once you start to luff over, the pendulem moves and unlocks itself.

take a look
Towermate

73 si.

Santas been

Christmas morning opening my presents, a box post marked, USPS. Hmmm looks interesting.
on opening the box it was a KPOD from elecraft, well from waters and stantons, hockley.
it was on my list.

Time to get it plugged in and see what all the fuss is about.
easy enough to get it working and powered up.
first job was to update the KPOD'S firmware as recommended by elecraft.
my K3S is running the latest firmware. two connections later and we have control over the VFO's and RIT.

downloaded the elecraft programmers manual, so time to programme some macros.

I have only programmed four macros at present.

after a short while of usage I really do think it has made a great radio even better.
cant wait to try it out in a contest.

73, SI.

PC Monitor QRM

purchased a new PC Monitor this week. after choosing carefully for a known manufacturer to hopefully eliminate any  QRM.

I purchased a Philips make. after setting it up at the shack it was time to check for any QRM.
the only place I cold find any was on 28MHZ. a sharp rasping buzz. out with the AM receiver, yes it is the PSU inline with the power cable. I added some clamp on ferrites, still no good.

I then added a ft240-43 toroid on the output lead and added some clamp on ferrites to the input lead.
hey, noise eliminated.

happy days..

73, si....

BOUVET ISLAND

Bouvet island is scheduled to be QRV early 2018.
no firm dates have been set.

web site BOUVET ISLAND

73 si..

STACK MATCH

I recently built a stack match.
A stack match is used so the user can have two antennas connected at the same time.
what good is that ? it allows you to have one antenna higher than an other. giving you two different arrival angles at the antenna. arrival angles change throughout the day and time of year.

So what good is a stack match ?
As already said, It allows the user to have two antennas at the same time or switch between the two to hear which antenna is hearing the wanted signal better.

My design was drawn on a peace of paper at work.

 

for the transformer I used a single FT240-31 toroid. I used #12 enamelled wire paired and six turns through the toroid. this was my start point.

 

 

I then laid out components to see which way would best fit the aluminium boxes I had.

 

 

Then I started to make the switch to select both or either antenna. this was a simple rotary switch with 12vdc. connections were made with CAT5 cable with ferrites either end.

 

 

LED's to show UPPER, LOWER or BOTH antenna selection.

 

 

All boxed and ready for testing.

 

I first connected an antenna and a dummy load to the outputs. I then checked to make sure the switching was working.

 

then using my antenna analyser, switching both or either antenna in and out. across 21MHZ VSWR was no worse than 1:5.1

I have tested with same set up but with radio and amplifier. analyser doesn't lie. 

 

 

designed by me, loosely, built by me and tested.

 

 

73, si.