Friday, November 23, 2018

If the Antenna Fits Use It: Myantennas.com 80-10 End Fed Half Wave

My backyard in Panama City, FL got cleared of trees and a storage building due to Hurricane Michael. My 80-meter doublet that was supported by a large pine tree is no more. I now have an open slate for antennas. Of course, a tower and a beam are possible.  But short of that what could I do.

I finally decided to try the myantennas.com 80-10 EFHW 1K. I have used it for Field Day with success. EFHW is End Fed Half Wave. For 80 meters an EFHW is roughly 130 feet. Fed from the end it has a high impedance and requires a matching transformer. I am pretty sure the myantennas.com EFHW has a 49 to 1 Unun in the box. On the harmonics, the antenna is a multiple of a half wave and has the same impedance at the end. That covers 80, 40, 20 and 10.  However, the antenna is quite usable on 30, 15, 17 and 12 meters also. I checked the SWR on all bands in the shack. The SWR is under 2 to 1 on the lower half of 80 meters, 40 meters, 20 meters, 30 meters, 15 meters, and 12 meters. 30 meters is under 2.4 to 1. This is the closest to a tuner-less antenna I have used.


myantennas.com 80-10 EFHW 1K



Physically, I took advantage of my patio cover, camo poles and my scraggly popcorn tree that made it through the storm, I had previously wanted to cut that tree. I used a 16-foot camo pole at the feed point, a 20-foot camo-pole, and the tree limb to support 80 feet of the antenna. The last 40 feet of the wire slopes to the back fence at a 90-degree angle to the rest.





This link gives some insight into the radiation pattern. I should do my own EZNEC model for my particular layout. Anyway, we will see how it plays out on the bands. Since I am not a DXer or Contester I think it will do fine.






Tuesday, November 6, 2018

N4KGL RaDAR Challenge Report November 2018.

Our RaDAR team, Dennis WA6QKN, Suzy and I, had ideal weather for the Nov 3rd, 2018 RaDAR Challenge. Our venue was Topsail Hill Preserve State Park near Desitin Florida. The paved trails and the cart we used made our transitions easy.


Our first location at the main parking lot at Topsail Park.
Our first location, EM60UI79AA, was at the main parking lot. I attempted a SO-50 Satellite contact but had no luck squeezing in. FM satellites are very congested, particularly on weekends. Likewise, an attempt to make a RaDAR to RaDAR QSO with Pat N5VMO in Arkansas failed on our end. If you don't have the PSK-31`setup working before the event don't expect it to work in the challenge.

The one-kilometer transition was easy even with the cart loaded with the Icom 7100, 30 AH battery and antennas.
We got our first five contacts on 40 meters CW using a low 40-meter dipole. The rig was an Icom 7100 running about 70 watts. The rig was set up on the dog stroller we use as a cart. I faintly heard the letters "kot". That was VA3KOT John Corby calling from Ontario, but the propagation just was not right for a contact. We did work WW1USA from the World War 1 Museum in Kansas City, MO.

Our second location in the park.
Then, it was off to the second location, EM60UI67PU, one kilometer away via the park trails. Suzy loves the trek. We set up a 20-meter dipole this time. With some effort, we got the five contacts on CW. A surprise was a call from CS7AFI in Portugal. That counts for the intercontinental DX bonus.

Dennis WA6QKN logging contacts.
The third location, EM60UI58TT, was on the trail to Campbell Lake. We used the Chameleon vertical whip antenna for 20-meters supported by the cart and two quarter-wave radials. This time we got a string of five SSB contacts by calling CQ POTA. The contacts included Puerto Rico and Ontario.

Dennis surveys Cambell Lake. It is a coastal dune lake.
We still had time left, however not enough to get to a fourth location. Instead, we treated ourselves to the view at Campbell Lake. It was beautiful. Then we had the return walk to the parking lot. My Fitbit registered 10,000 steps for the day.

Suzy makes her own contact and gets a belly rub.
Dennis and I have done several challenges and have made it to four locations in four hours. Usually, we have a few locals and chasers but not this time. We are frankly hard to follow if we go to search and pounce. Also, propagation would be difficult back to Panama City. This outing we enjoyed the break from the hurricane recovery in Panama City. It will be a long time before the clean-up and repairs are done. Things improve a little bit every day there.

Note A RaDAR email group is picking up interest at https://groups.io/g/RaDAR Please join if you are interested in Rapid Deployment Amateur Radio (RaDAR).


Thursday, November 1, 2018

Top Sail Preserve State Park will be the N4KGL RaDAR Challenge Venue

The next RaDAR Challenge is Saturday, Nov 3rd, 2018. Dennis WA6QKN, Suzy and I will form a RaDAR team using callsign N4KGL. We have chosen Top Sail Preserve State Park for our venue. Top Sail is on the Gulf Coast near Destin, Florida. Top Sail has paved trails through the park. Those will be ideal for on-foot or on-paw RaDAR. Per RaDAR rules, we will make five contacts and then move one kilometer to the next location.



We have chosen to start with a SO-50 Satellite pass at 1545 UTC from the parking area. The park is in grid EM60.  We hope for at least one sat contact for the RaDAR bonus. If we get five on the sat we would be ready to move. Most of our operations will be on 40 and 20 meters HF. Note Top Sail is K-3664 for POTA, Parks On The Air.



We will proceed on the trails toward Campbell Lake, stopping every one kilometer to make our five contacts. We will be using a dog stroller to carry the Icom 7100 100 watt rig and battery, It takes little effort to push the stroller even with heavy gear. The stroller can support a vertical. A dipole also can be used by attaching a PVC conduit mast to the stroller. The dipole ends will be supported by 10-foot poles.

We have four hours to make contacts The radar exchange includes RS(T), name and location. The location is preferably a grid square of six digits or more. We will use these frequencies

7.029.5 CW
7.296 LSB

14.059 CW
14.346 USB

However, if there is no luck on those frequencies, we will hunt and pounce. The pace is so rapid it is difficult to spot ourselves. We will do the best we can. Check DX Summit for N4KGL and K-3664. Ham Alert is a good idea. Set that up ahead of time for N4KGL. RaDAR Ops can use a RaDAR group on WhatsApp. Ask me for the invite link.

In any case, the weather forecast for Saturday is looking ideal here in Northwest Florida. We hope for some RaDAR to RaDAR contacts. Those are always a challenge but very rewarding. If RaDAR interests you please check out the RaDAR group and the  Google+ Community