Springtime + Aluminum (12-m OWA construction)

3/27/2022 – With a box of shiny tubing from DXE, and an OWA design from my friend, I tackled an antenna construction project today.

Shiny tubing for tower bling!

Since selling my Lightning Bolt 2-element 5-band cubical quad a few years ago, I have not had an antenna for 12 meters. My DXCC count is low on that band, so I figured that with the uptick in propagation, now is as good a time as any to tackle this project.

Some time ago I asked around for an OWA design to use a 24-foot boom (salvaged from an old TH6?). Once I had the design in hand, I plugged it into EZNEC 6.0, and agreed with the designer’s conclusions. Download my EZNEC file for this antenna. I made a parts list and placed an order from DXE for the tubing (surely there are others suppliers around, but I can’t find them using Google search) and another from McMaster-Carr for the hardware needed.

With some aluminum flat bar cut to length, a drill press made quick work punching holes in the boom-to-element plates (I used a DXE model as a template).

A pile of shavings!
Stack of six boom-to-element plates

The Sawzall was employed to cut the tubing to the needed lengths, followed by a thorough deburring of all tubing ends. Measured and marked the “exposed” lengths of tubing, inserted to the marks, and drilled three 1/8″ holes for pop rivets. Pulled the tubing out, deburred the drilled holes, then coated the insertable tip with a copper-impregnated anti-seize compound. Aligned the holes and riveted the tubing together. The halves of the driven element are separated by 2-inches, supported by a 0.75″ fiberglass rod inserted into both halves.

With the elements assembled, I moved outdoors to assemble the boom and install the boom-to-element plates. After that, installing the elements was a piece of cake.

This perspective doesn’t present the antenna well

Still sitting on sawhorses, the initial SWR and R,X sweeps are nearly identical to the EZNEC model.

Initial sweep still sitting on sawhorses
EZNEC 6.0 model’s SWR curve

I’ll update this post when the antenna is in service. I think it is going to be a flamethrower!

EZNEC 6.0 modeled pattern

4/15/2022 – Good Friday, and good Friday! I was off work. Woke up at 0400 and was wide-awake. Decided today was a good day to install the antenna. So, working alone with tractor and pallet forks, along with an 8-foot ladder, I was able to remove the KT-34 and install the 12-meter yagi. Initial tests are promising – worked YV4 and VP2V right away, 100 watts CW.

4/15/22 – 12-meter yagi now flying at 50 feet

Boom + Microphone + Mount <$90

A year ago I wrote about my Christmas 2018 “self-gift”, the pair of JBL Control 2P powered monitor speakers that I integrated into my shack with a Mackie 1202-VLZ Pro. This continues to be enjoyed in my shack because I can listen to multiple sources without being tethered by a headset cord.

Similarly, I’ve been tethered by headset cord to all my microphones because they are all headset mikes. For some time, I had desired an articulating boom + microphone setup. However, I did not want to pay for brand new equipment just to try something out, and I wasn’t really sure how or where I would mount it to not be in the way when not using it.

I had read on the Elecraft reflector some interesting commentary about brands of microphones. As the K3 has a built-in transmit equalizer, it seemed the consensus leaned away from the brand that is marketed as the elite microphones for ham radio. I studied some other brands and the frequency response and cardioid patterns of several microphones.

Shure PGA 48 response charts

Soon, I found one that I was willing to buy and try. I found a new condition, open box Shure PGA48 with a 15-ft XLR cable and mic clip on eBay for $33 to my door.

What’s in the box.

At the same time on eBay, I found a used mic boom, Heil PL2 missing the cable covers and any type of mount, for $50 to my door. Tiny zip ties will hold the cable just fine.

The items arrived, and I was left with figuring out a way to mount the boom. An ‘ah-ha’ moment struck, and a simple solution was found. My radio desk has a brace under the tabletop in just the right place. I drilled a 5/8″ hole through the tabletop and into the 2×4 brace for a total depth of 2 inches. After vacuuming the shavings out, I pressed a steel sleeve bushing O.D. 5/8″, I.D. 1/2″, Length 1-1/2″ ($3 at the local hardware store) into the hole, creating a flush-mount for the boom to sit in. It works perfectly!

$3 steel sleeve bushing O.D. 5/8″, I.D. 1/2″, Length 1-1/2

Next was to listen to how I sounded with the existing TX EQ settings in the K3. I had a set of “rotating” TX macros set up to allow me to quickly step through five different TX EQ settings.

RAG-1 TE+06+06+00+06+00+04+08+12;MN110;SWT24;SWT21;SWT14;
RAG-2 TE+00+00+10+04+04+06+08+12;MN110;SWT27;SWT21;SWT14;
DX TE+00+00+00-06+00+04+08+12;MN110;SWT29;SWT21;SWT14;
VERY-DX TE-06-06+00-06+00+04+08+12;MN110;SWT33;SWT21;SWT14;
FLAT TE+00+00+00+00+00+00+00+00;MN110;SWT13;SWT21;SWT14;

After transmitting at 0.1 watts on 10m and listening via another K3 on a distant beverage antenna, I have settled on these as my initial settings for the new microphone:

SHURE TE-16-14-04+00+02+04+08+12;MN110;SWT34;SWT21;SWT14;
SHURE-DX TE-16-16-10-06+04+06+08+12;MN110;SWT32;SWT21;SWT14;

Yesterday afternoon, I enjoyed many casual QSOs on 17m and 20m using the completely “untethered” accessories. I even experimented with VOX and improved the settings to work effectively with the Shure mic.

And here it is! Boom + Microphone + Mount <$90

Summary: This is a worthwhile purchase and it will enhance my casual operating enjoyment.

Pondering other 160m transmit antenna

I have a 160m Inv-L, feed against 40 buried radials 125 long. The vertical component is parallel to my existing tower, tapering from a wide (~15 ft) space at ground level to a narrow (~4 ft) space at 77 feet above ground, then heading away from the tower for another 40 feet.

I have a very tall (~100 ft) pine tree at the edge of my property, north by northeast from the tower at a distance of 175 feet. I’m thinking of using the pine tree to support the vertical component, and going to an elevated radial system.

This is an interesting read about elevated radials:

https://rudys.typepad.com/files/elevated-ground-systems-article-final-version.pdf

What are your thoughts?

New Life for old EZ Way Tilt-over Crank-Up Tower

 

Several years ago I acquired an unidentified tilt-over crank-up tower.  Manual winches, it appeared to be about 60 feet tall.  The deal was take it down and it is yours.  So it has sat behind my shop for about 10 years.

Recently, I saw a picture on the internet of an identical tower, and it was identified as an EZ Way, not that it mattered much to me at the time.  However, the motorized trailered tilt-over crank-up tower that our club has used for Field Day for many years isn’t available this year.  Ah-hah!  Now I have a reason to be interested in the EZ Way.  Of course, it was designed to be ground mounted.  But I have a heavy trailer, and began considering the possibility of mounting the tower, temporarily and safely, on the trailer.

Short story is I reinforced the under frame at the four anchor bolt points for the tower base, and  also fabricated a support for the long end of the tower to rest on when in transit. 

All attachments to the trailer are bolted, so the installation is easily reversible to return the trailer to normal utility use.  The project turned out quite nice!

For FD, I don’t expect to need to crank up to more than 45 feet.  Exercising the KISS principle, I’ll install a flat top plate with a 3 ft pipe stubbed up.  Then, I can slide the larger diameter mast over it, and rotate it by a pull rope attached to one end of the boom.  The antenna will be a KT-34.

Many thanks to Jim W5LA, Mark K5MSB and Shawn WA5VQP for the helping hands on the labor to make this all possible. 

Addition of a K3

01/14/11 — A new (to me) transceiver arrived today!  K3 #0251 – I’m looking forwarded to giving it a good workout to evaluate my preference between K3, 756Pro2, and FT1000MP.  

Building….

12/04/10 — Constructed an Inverted-L for 160 meters.  Vertical component is 75 ft and horizontal is 100 ft.  It is attached to Tower #1 at the 75 ft standoff, and the horizontal runs due north toward a tall pine tree.  It is grounded to the same radial field used for the 80m shunt fed tower.

Here is the file for EZNEC model of the Inverted-L

12/02/10 — Built a simple contesting accessory – a footrest with footswitch.  Thanks WX9T for the idea!

Coax Stub Filters

11/04/10 —  Installed the final 2 coax filter stubs:  a CS-1 on 80m and a CS-9 for 160m.  Here’s what the installation looks like in the antenna switching shed.

Coax Stub Filters installed at SixPack on antenna ports:

    * 10 meters – CS-6 (1/2 WL-open 10m) & CS-4 (1/2 WL-open 20m)

    * 15 meters – CS-3 (1/4 WL-shorted 40m)

    * 20 meters – CS-4 (1/2 WL-open 20m) & CS-5 (1/4 WL-shorted 20m)

    * 40 meters – CS-3 (1/4 WL-shorted 40m) & CS-7 (1/2 WL-shorted 15m)

    * 80 meters – CS-1 (1/4 WL-shorted 80m)

    * 160 meters – CS-9 (1/4 VL-shorted 160m)  

10/23/10 — More work on stub filters.  Added CS-3 and CS-7 to 40 meters.

Tested to determine cross-band interference.  I used the lower C51XR for all 10, 15, 20 & 40 tests, and used both the 80m shunt tower and the 80m dipole on both transmit & receive.  Transmit mode CW, power out 1.5kW. Receive mode CW, filters 6.0kHz.

Here is the matrix:  

 LEFT RADIO TX BAND     
RIGHT RADIO RX BAND1015204080160
10X<S0<S0, avoid harmonic>S9+50<S0, avoid harmonic>S8nilnil
15nilX<S0, avoid harmonic>S8nil, avoid harmonic>S9nilnil
20nilnilXnil, avoid harmonic>S9nilnil
40nilnilnilXnil, avoid harmonicnil
80nilnilnilnilX<S3, avoid harmonic >S9+20
160nilnilnilnilnilX

These results pleased me for first attempts at coax stub filters.

10/19/10 — Continued working on stub filters.  Added CS-5 to 20 meters, and installed CS-6 & CS-4 to 10 meters.

10/16/10 — Found burnt barrel connector in top 20m antenna feedline (it had to be 120 feet off the ground).  Replaced it and corrected the intermittent high SWR on that antenna.

10/06/10 — Tilted over Tower #3 and realigned the cubical quad to correct its heading.  It slipped on the mast during a storm last year.

09/29/10 — Began building and implementing coax stub filters on the output of SixPack #1 to Tower #1.  I have MUCH to learn in this area.  Using an AIM4170, I cut two pieces of RG-213 to 1/4 WL at 7.150 MHz.  One I made into a CS-3 and installed on the 15 meter port of the SixPack, and the other I made into a CS-4 and installed on the 20 meter port of the SixPack.

For reference, I’m using Managing Interstation Interference 2nd edition by W2VJN as well as K1TTT’s online Technical Reference and his online copy of K2TR Coax Stub filters article.  I used the K2TR drawing, and cross-referenced it to the table on page 46 of Managing Interstation Interference .  Here is the drawing, with the notations from page 46 superimposed.

Now I have to get more RG-213, more UHF ‘tees’, and spend more time learning and tweaking!

Another good source of info is “Some Q&A About Coax and Stubs for Your HF Station
By Jim Brown K9YC

Shunts and Beverage antenna system

09/25/10 — Finished the last of my 4 beverage antenna by installing the wire for Europe.  Worked on a sticky relay in the antenna switch.  Cleaned up the shack a bit, as a first step toward the CQ WW group’s arrival late next month.

09/20/10 — Built a Magic-T splitter for the beverage antenna system.  Installed an A/B relay to select either the 80m dipole or 80m shunt fed-tower.  Replaced the RF bypass capacitors in a lightning damaged SixPack.

Went through my paper QSL cards to update my DXCC totals, and found several new ones that I will send to ARRL HQ.

09/16/10 — Completed tuning the 80 meter shunt feed.  My goal was to have it resonant at 3.6MHz.  I think I was pretty successful with the tuning.  The shunt wire is spaced 36 inches from the tower, and the shorting bar is about 27 feet up.  

09/11/10 — Installed the permanent shunt feed system on the tower.  Built the necessary standoffs to mount the vacuum variable cap in the tuning box.  Assembled everything with copper strap for low inductance.  Silver soldered 4″ copper strap to the ground ring at the tower base and connected to the base of the tower as well as the coax shield on the shunt feed.  Used an AIM 4170c to get baseline readings.  It looks like I need to raise the shorting bar about 12 to 15 inches up the tower.  It will have to wait until next week.

09/10/10 — Completed the beverage at 270 and 315 degrees.  Installed antenna switch at central beverage switching point.  Installed F connectors, and hooked up a receiver.  Gave it a try.  Heard BU2AQ at 1045 UTC on 80m.  Could not even discern any signal there if listening on the transmit dipole at 75 ft.

09/06/10 — Continued to work on beverage antenna system.  Figured out a way to also have a 480 ft beverage at 90 degrees.  Set more 4×4-12 ft posts.  Built 4 transformers using the W8JI design.  Buried feed line to all 4 beverage feed points.  I sure like the radial burying plow!  It is coming in very handy!

     

09/05/10 — A very pleasant surprise!  KG5VK paid me a visit this afternoon.  As a first-time visitor, I gave him the nickel tour.  Then we talked multi-op strategy.  I’ve got several items to do in and around the station now!

09/04/10 — Began the expansion of my beverage antenna system.  Set several 4×4-12 ft posts.  Strung 800 ft beverage at 270 degrees and 485 ft beverage at 315 degrees.  Cleared underbrush to extend former 285 ft with goal of at least 500 ft at 45 degrees.  Still have to construct the transformers and place the ground rods at both ends of each beverage.  Used my radial plow and buried feedline & control wires from shack to central beverage switching point.

 

With help from K5RUS, we also worked on shunt feed on tower for 80m.  Still in experimental mode – we did locate the approximate feed point and determined approximate capacitor value.  Now I’m ready to build the final tuning assembly and secure the shunt wire more securely to the tower.

Also sanded and applied 2 coats of polyurethane to desktop for multiplier operating position.  Replaced feedline from multi position to antenna switch shed.

08/30/10 — Finally repaired my TopTen Band Decoder/Yaesu with source driver mods.  It was damaged in the May 2009 lightning fiasco.  I just had not made it a priority.  It is now on Radio 1 (left), and automatically switches the ICE 419 bandpass filter between the FT-1000MP and AL-1500, and the SixPack for antenna selection.

08/28/10 — Finished burying radials this morning, with a total of 40 radials, most about 125 feet long. A few had to be shorter. In all, used 5,000 feet of wire.  Silver soldered the radials to the ring of #4 solid copper wire around the base of the tower.  Installed the shunt wire up the tower to 75 ft, and put the shorting bar at 36 ft.  Now I have to build the tuning network and put in a weatherproof box.

08/26/10 —  Buried another 16 radials this afternoon.

08/25/10 — Began burying 1/4 wavelength (~125 ft) radials around my 120 ft tower.  Got 14 done (1,750 ft of wire).  I’m installing 36 radials, 10 degree spacing.  The ends of the wire are 21.6 ft apart.  The goal is to shunt feed the tower on 80m and 160m.  This project began with the purchase of 5,500 ft of 12 gauge solid THHN wire and 2 vacuum variable caps at Dayton in May.

08/23/10 — Modified my middle-buster plow to be a radial/cable burying plow, complete with wire roll holder and dispenser tube.  It only took about 2 hours .