Sunday, June 22, 2014

Recumbent Ride -- Willard Marsh Loop

Yesterday I spent a few quality hours on my recumbent bike touring the Ohio countryside.  I wanted to ride somewhere new but I didn't feel like loading up my bike on the car rack and driving just to ride.  The only problem with that is I have to ride for about an hour in any given direction just to get to roads I've never ridden.

From my driveway I headed north keeping to rural back roads I like to ride.  I didn't have a route planned I just ambled along choosing my route as I went.  My ride took me roughly twenty miles across my county and to the border of Huron County, about 30 miles south of Lake Erie.  Most of the country is farmland and with all the rain we've had the crops are growing well. 

On longer range rides I've taken to using my smartphone map to aid in navigation and it has made it easier to enjoy the ride more than flying blind trying to avoid the busier state highways.  In the old days I used to make a photo-copy of a section I planned to ride from a page in the Ohio Atlas & Gazetteer.  That analog map worked fine but occasionally I would ride off the paper and be back to guessing.  That's not always the best method when a couple hours from home and under your own power.

I wasn't planning a big ride but the conditions were perfect with just a slight breeze from the northwest and mild temperatures in the upper 70's.  I felt good and the miles kept adding up.  Consulting the map I found a place I never been that would put me about 25 miles north of home.  

Willard Marsh Wildlife Area is a 1,676-acre conservation area located a few miles southwest of Willard, Ohio in southern Huron County.  Access to the area is by gravel roads which line the perimeter of the park.  I try to avoid gravel if I can help it but the HP Velotechnik has no problem gobbling up gravel miles.  These roads were in super shape so going wasn't all that bad at all.  The scenery made it worth it.

From there I started the trip back to home and ended up with a satisfying 50 mile ride and new route entry for the logbook.

Bike:   HP Velotechnik
Ride Time:    3:49
Distance:    51.18 miles
Average Speed:    13.3 mph
Max Speed:    27.7 mph


Tuesday, June 17, 2014

W8MDE 10 Meter Rotatable Dipole

I spent Father's Day finishing up my 10 meter rotatable dipole antenna project for this year's ARRL Field Day which is coming up in a couple weeks.  I wanted to change things up and try working a different band other than 40 meters where I have operated the past few Field Days.  The sun is putting out as many sunspots as it's going to during this solar cycle so it has the 10 meter band coming open usually every day for world wide communication.  So this and the fact that our club's field day location has a lack of trees for antenna supports I decided to focus on the shortest of the high frequency wavelengths.

This is the second homebrew antenna project I've built since becoming a radio amateur in 2008 and I had a great time with it.  A dipole is a most basic type of antenna and is easy to build.  Dipoles are usually made of wire and strung up between two supports but aluminum tubing can be used for the elements which is what I used so the antenna would be self supporting.

Materials I gathered from my spare parts bin and local hardware store.  I also used a new to me vendor; DX Engineering, to supply some high quality saddle clamps for the mast to Lexan plate connection and fiberglass tubing for the mast.  DX Engineering is located here in Ohio so I can consider all my antenna components for this project locally sourced.  The Lexan sheeting was a scrap piece from work and I fabricated a small aluminum angled bracket to mount the coaxial connector.  The antenna elements are made from anodized aluminum tubing I got at the hardware store.  

The jumper wires are #14 braided copper with crimped and soldered connectors.  The white PVC pipe acts as a support sleeve for the aluminum antenna elements.  I drilled a small hole on each side so a stainless steel sheet metal screw can provide secure electrical contact between the jumper wire and the aluminum tubing.  The feed line attaches at the bottom of the bracket.  In the picture the connector is wrapped with self vulcanizing tape and a cable tie to weather proof it.  Shortly after taking the picture I placed a blob of RTV 100% silicon on the top of the coax socket to further protect the exposed solder joint.  The ground side of the dipole attaches via a ring terminal connected to one of the socket mounting screws.

The cool thing about half wavelength dipoles is that the physical length can be approximated by a simple formula:  468(ft) / frequency (MHz).  I wanted my antenna to be resonant on 28.050 MHz so 468 divided by 28.050 equals 16.684 feet. That number should be close to the overall length of the antenna.

I designed the antenna elements using 6 ft sections of tubing with a smaller diameter 3 foot section that telescopes into the bigger piece.  This allows me to adjust the length of the element legs in or out to set the point of resonance of the antenna just where I want it.

With the help of my antenna analyzer I noted the SWR then extended the ends a couple inches at a time and rechecked the antenna with the meter.  After repeating this process a few times I observed the low point of the SWR curve move right into the area of frequency I plan to operate.  I locked the element tips down tight with a small hose clamp.
SWR Curve

27.062     1.5
27.303     1.4
27.573     1.3
27.955     1.2
27.968     1.1
28.197     1.1
28.208     1.2
28.622     1.3
28.902     1.4
29.180     1.5

I'm sure most hams would agree the most exciting part about making your own antennas is hooking up the rig and seeing if one can actually make a contact using the homebrew equipment.  It was late in the afternoon when testing was complete and I headed inside to my operating position to hook up the antenna to my transceiver.

Right away I heard signals coming in so that was a good sign.  I set my dial to 28.076 MHz and sent out some CQ calls using the digital mode JT-65.  After a few tries with no response I looked for a station who was calling.  Up popped a ZL prefix station on the decode screen which I recognized as one from New Zealand. It took two tries and on the second go ZL4AD received my signal and we completed the quick JT-65 contact spanning 8,811 miles between us.  

With that as a first contact I'm going to call this antenna project a success and I think the thing will work fine for making a few local stateside contacts during the Field Day event.

Friday, June 13, 2014

Mail Pouch Tobacco Barn

Morrow County, Ohio

I noticed this old barn earlier in the year and finally got out on the motorbike to snap a picture for my collection here on the blog.  The old structure has seen better days and the paint is weathered but at least it won't degrade any more here in digital form.

It's been a hectic and busy spring here and it's kept me away from blogging.  I've got lots of activities going on which are generating some good content so slow but sure I'll get some more stuff documented here at RCT.