Friday, February 10, 2012

     After several attempts to thread the 1/4 inch aluminum rod, I finally gave up.  For the most part the threads were crooked.   However with Winter being here it was time to tackle this again.  This time some better tools helped.  Part of the problem was the threading die getting crooked on the rod and making threads at an angle.  The picture here shows my solution.  I took a 2 inch square board and drilled a 1/4 inch hole in it.  Sliding it on the rod ahead of the treading die keeps the die correctly aligned and makes a nice thread. 
     
     Here is the assembled PAC 12 with a 20M coil attached.  You will note there is no joint in the aluminum section.  Jim Bennett originally designed this to fit in a 12 inch parcel.  I really did not need that so I left rod at 24 inches instead of cutting them at  12 and adding a coupler.    I have added a small tripod used for spotting scopes as a base.  I have tried it on the commercial version and the work fairly well.  I will test it out shortly. 

Tuesday, May 3, 2011

     Last September, I had the opportunity to take a trip up to Mt Evans in Colorado while visiting family.  The image is from a cell phone, yes I forgot to take a real camera.  The young person is my grandson.  Next to me is the Elecraft K1 attached to my PAC 12 antenna set for 20Meters.   The view is looking south from the peak at 14,210 ft. Tried working K9JKLR in Hebron, IN  but 5 watts even at 14,000 plus  feet was not enough to make the trip.  Could not raise anyone else either.  The view is just below the peak looking south.
The trip was pretty spontaneous and I did not know about the Summits on the Air program (SOTA) or would have tried activate Mt Evans perhaps stay longer and make some contacts.
     With warmer weather headed up North, it will be time to get out for portable operations.  I will be looking at a new vertical and a couple of wire antennas.
73

KC8ZTJ

Wednesday, August 11, 2010

Pac 12 Production

James Bennett anounced on the Pac 12 Yahoo Group that Pacific Antenna was suspending production for lack of machined parts.  James will not outsource so he has refunded money on current orders.   So It looks like back to the original design and home brewing.  Here we are cutting threads on the !/4 inch aluminum rod.  Will post more as I go along.  You can access the original Pac 12 here.  Directions are pretty complete and it uses very available hardware.  The only issue is with the Collapsible section. I have tried to contact Pacific Antenna but have not had a response yet.   There  a couple leads to follow.  Buddipole offers a 72inch telescopic antenna with a threaded base.  One is on order.

Sunday, August 8, 2010

Several people have asked about the Pac 12 at club meetings and Lost Team outings.  Glad to see that but have also found out that Pacific Antenna has stopped taking orders due to a parts shortage.  I gather that one of there suppliers has closed shop?   So the club build of the Pac 12 is on hold until we can find the necessary parts. There are a couple of promising leads but will wait until we have parts in hand before proceeding. 

Thursday, July 15, 2010

Portable at the Red Cross Chapter House

Took the Pac 12 to the Red Cross Chapter House in support of my presentation on the Soft Rock Lite II SDR radio. Everything worked well.  The Pac 12 is mounted on a spotting scope stand.  The scope stand has worked very well.  However, one has to watch for wind as it can be blown over easily.

Tuesday, June 22, 2010

Operating today from the same public park in Portage, Michigan.  While  it is not very clear, I have added a 40m counterpoise made of TV twin lead. You can barely see in the picture above.   Conditions today were not so good for QRP radio.  Did manage to QSO with K3MZY Leo in South Carolina using the counterpoise.   Still do not have coils wound for 15M or 20M which would help. 
New coils are the next project and working from a different location.

Sunday, June 13, 2010

Hypothesis

I wrote about the twisted feed point wires and how untwisting them seem to correct a problem.  I got to thinking that maybe my contact with Pete in Minnesota was dumb luck or just better band conditions.  I knew that I would have replicate the original conditions and find a way to measure the result. 
     I occurred to me that I could use a field strength meter.  I dug out an cheap Vanco SWR/Field Strength meter.  I also decided to set up a local park to get away from the antennas at home and interference they might provide.  Lakeview Park in Portage, Mi is about a mile from my house and nice place to visit.  Plenty of picnic tables to use as a test bench.  Not exactly the same conditions as the last time but very close.

I chose the 40 meter coil and low and behold I found that I had forgotten my radials at home.  However I did have a TV twin lead counterpoise so that was attached in place of the Pac 12 radials.  Barely visible in the picture is an orange spot back by the tree which is my winder for the lead.

     I also brought some test leads try and replicate the miss wired feed point.  One can sort of see the test leads on the antenna to the right in the picture.  After finding a spot on 40Meters that was clear I called CQ and took the follow reading on the Vanco FSM.
Of course the next step was to remove the test leads and retake the reading.
Viola! it worked.  Test is I believe reasonably accurate.  I stood in the same place both times and used the same power setting on the radio.   I am confident I can replicate the test in the future.    While at the park with all this equipment was able to make another CW contact with Ray KC0URL in Minnesota again. 
     Lesson learned.