Tall Pines Beg for an Antenna

My parent's home in Dothan, Alabama is on Pine Tree Drive . This is where I grew up and started doing ham radio in the late 60s. The tall pine trees are impressive and beg for an antenna. However, the first limbs are 50 feet plus high. It was not possible for me to throw anything that high. This was my motivation to get the Big Shot Slingshot. I was able to get lines over limbs at the 50 plus foot level with the Big Shot. As usual the layout in most lots favors an Off Center Fed and this is my first OCF. The shack is my Dad's workshop near the back of the lot. This weekend was my chance to get the OCF up. I am using a Balun Designs 4 to 1 balun fed with 70 feet of RG-8X. The long end is 90 feet and the the short end is 45 feet long. The long section is East West and is over the roof. The short section does a dog leg to the North East. The antenna is 40 feet above the ground. I am leaving ample slack as the pines can really bend in high winds. So how does it tune? Well 80 meters is 5.5 to 1, 40 meters is 2.7 to 1, 20 meters is 1.7 to 1 and 10 meters is 1.8 to 1.  So no tuner on 20 and I am very happy with that. With the exception of 80 I think this is par for the course. We will see if my internal tuner on the IC 703 will handle the SWR on 80. I think it will.  I always have limited time in Dothan so I am calling this a success! I did work  MO and AZ using QRP on 20 meters while I was there.

Greg

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Enter The Black Widow

I have been reading about the Black Widow vertical and similar antennas using the BNM Black Widow fiberglass pole. I got over to Walmart and they had a 13 foot model for less than $10. I wanted to see if I could extend the military mast I use with the Widow. Indeed it will feed through a 4 foot mast section and wedge nicely out the male end. I used a little tape to stabilize it. So that means I can have a 13 foot extension that is light weight. Therefore the usual 20 foot mast can now be extended to 33 feet. It also dawned on me that a 20 meter ground plane could take advantage of this by taping the 1/4 wave vertical element to the mast starting at the tip of the Black Widow. The three radials meet the vertical element about 16 feet up.

So at last a portable antenna that is not a cloud warmer and is at a good height. I setup up this antenna for testing in the backyard and had a good run of QSOs with the Ten Tec R4020. I worked PA, ME, OH, IL, and MD. The MD contact was W3PO running 1 watt. I think the 20 meter ground plane is going to be a go-to configuration. You might notice I was using an external 10 pack of Eneloop AAs for these QSOs Velcro-ed to the bottom of the lap shack..

 Greg N4KGL

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Extending the BuddiStick for Parking Lot Portable

I have put the Buddistick at the top of my 20 foot mast before. However, just for fun I added a 15 foot wire running down the mast from the driven element. At the five foot level I convert to coax and attached the counterpoise there. It works out that using the two 11 inch arms and the telescoping whip plus the 15 foot wire is just right for 30 meters. For 20 meters remove all of the Buddistick except one 11 inch arm. On 40 add the coil and set the tap at about 50%. The counterpoise is set for about the same length as the vertical part except 40 which was 31 feet. From one perspective it would be more efficient because it uses no coil or less coil than it would without the wire. From another perspective the height of the antenna is less. In any case I'll have to try it out on the air. Note the overcast weather is due to Tropical Storm Lee which has given us light rain so far in Panama City.

"Extending the Buddistick"

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20 Meter Delta Loop Back Yard Portable

I always wanted to try a delta loop and I had my chance early on the 4th of July while visiting my Mother-In-Law in Conyers, GA. I got the idea from this link. I used a LDG 4 to 1 balun at the top and about 70 feet of wire. It tuned to resonance easily. The tip of the delta was about 20 feet and the bottom flat section was about 10 feet high. I setup with the 3 watt SST and worked ID, CT and OH. So I'll add this to the BYP Backyard Yard Portable playbook. Here are some pictures. The actual wires of the loop were pretty much invisible to the camera.

"Delta Loop July 4th"

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Shortened Dipole with Matching Section

I tried a shortened dipole (inverted V) by using the IMAXMIN.EXE program on the W5DXP no tuner page. The minimum dipole length the program will accept is 107.19 feet for 3.5 MHz. So I went with 108 feet. The Imax or good length of open  wire feeder is 29.7 feet for velocity factor of .9. My chosen feed-line is 300 ohm window line from DX engineering. Note I am using a bead type choke balun at the end of the 300 ohm feed-line and converting to coax.

I tried this out with a portable mast consisting of 4 foot military mast sections. The bottom is a tripod using a tripod adapter I found on EBay. There is a six foot section of PVC conduit at the top. This gives the antenna a support at the center of 23 feet. The ends are going to stakes or a low fence. The ends are only about 3 feet off the ground. The SWR was very good at 3.5 MHz. A pleasant surprise is that 7 MHz the SWR is under 3 to 1. A full size 80 meter dipole will have a very high impedance on 40 meters. But this dipole is usable on 40 meters with a the internal tuner of my IC-703. I had done a similar check out for a 7 Mhz dipole at 54 feet of length and it tuned under 3 to 1 on 20 meters with a 14 foot 8 inch feed-line.

Now back to the 108 foot dipole. I got it to work on 20 meters by reducing the feed-line to about 24 feet. To try out different feed-line lengths I have a lot of 300 ohm sections of different lengths. I am using the European terminal strips ( the larger size) to join the sections and this works well. So you might say the the 108 foot dipole is like the G5RV and I would say you are right. I don't have one but it likely works the same. The 54 foot dipole is close to a G5RV Junior.

Now I am looking to use either the 108 or the 54 foot version at Field Day based on space available. I am not convinced the guys on the mast are needed with the tripod. They may backfire if a car catches one and turns the whole rig over. I have some homemade A-frame masts from a prior Field Day that I could use to get the ends of the dipoles up at 13 feet.

So credit goes to Cecil W5DXP for this no tuner concept and for me it explains what is going on for the G5RV type antennas.

"Shortened Dipole"

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Inverted V Checkout for Parking Lot Portable PLP

It turned out after the morning rain cleared, I setup at George Park in Panama City. One goal was to test various inverted Vs with the 20 foot mast on the back of the truck as the center support. The two legs of the inverted v dipole were the Coleman Laundry line spools with 85 foot of wire in each. So I wanted to get the length for several bands. The lengths worked out to be

40 meters: 30' 9"/31' 9" some how I got the two legs a foot different.
30 Meters 21 9" each leg
20 meters 15' 5" each leg
80 meter 62' 6" each leg

So as I went along I was making contacts including

40 meters with Sierra at 2 watts
     K3AP Bob Ocala, FL
    WR4Z Jimmy Panama City, FL (I had sent Jimmy an email and he found me)
     K3RLL Bob Cassadaga, FL ( He was QRP in a park like me)

30 Meters Sierra at 3 watts
     W5TZC Larry Bismarck AR

20 Meters SST at 3 watts (It was the FISTS Sprint)
     W3OKC Steve PA
     KG2GL Tony NJ
     KA8HFN Larry OH
     W2ED Ed NJ
     AK5D Dave NM
     W7GVE Ed AZ

On 80 meters I just verified the inverted v tuned. I am really pleased with the Coleman laundry spools for wire. It does not cause any problems to have the extra wire spooled. So now I have more configurations for Parking Lot Portable ops where the space is available for the ends of the inverted V.

Greg N4KGL

"PLP Inverted V"

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W3EDP Antenna Checkout for PLP

I tried it and I like it. The W3EDP is a 85 foot long wire and a 17 foot counterpoise. The LDG 817 tuner lets me match it for 40 through 10 meters. I used LDG 1 to 1 balun directly on the tuner output for all but 15 meters and then switched to the LDG 4 to 1 to get 15 meters to tune. So this is just another possible configuration for Parking Lot Portable (PLP) ops.

"W3EDP antenna checkout"

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N4KGL Rocket Beacon Antenna Test

I tested the end fed half wave with the toroid transformer from the driveway today. The high end was 24 feet up. I worked K3Y/2 SKCC special event station using 2.5 watts. I got a 449 report. He was 910 miles away in Tuckerton, NJ.That is about par for QRP. So I am thinking this arrangement is good enough for the beacon rocket. There really is no way to know the impedance while it is airborne I just want to be as good as I can be to the transmitter.

Greg
N4KGL

N4KGL Beacon Rocket Antenna Coupler

I wound the FT-114-43 toroid with 4 turns on transmitter side and 32 on the antenna side. I setup a sloping half wave with the high end 24 feet high. I could not get the SWR down and the noise bridge had the R near zero. So I started taking off turns on the antenna coil and the SWR got better and better until 19 turns it was about 1.5 to 1 then I shortened the antenna a bit and it went to 1 to 1. This might be a mirage but I'll take it. So I might try to make some contacts with this wire and see if it is an antenna or a dummy load. With the 4.75 ratio I ended up with that would say the antenna has an impedance around 1200 ohms. I did all this testing in the driveway and I may have gotten a couple of passer-bys interested in ham radio.

N4KGL Beacon Rocket Alternative Matching Circuit

I found this link that describes an alternative approach for matching the transmitter to an end fed half wave antenna. Since it was used for the IHAB-2 20 meter balloon beacon I think I am on the right track. It uses a transformer wound on a FT-114-43 toroid. This will get rid of the Par matchbox, coax, right angle connector and so forth. That will be lighter and will fit in the body tube. So I'll send off for the toroid. Much better!

Greg

N4KGL

The EFHW - a monoband end-fed half wave for 10m, 20m or any other HF band

I like using coax for the capacitor and I would really like to try one of these. Thanks to G0KYA. He did a nice job on the article.

W5ALT Antenna Notes

Link to Antenna Notes

One of the best write-ups on antennas I have seen. The following statement confirmed what I suspected but it is nice to see it in print

In other words, the common SWR meter measures the ratio of impedance to 50 ohms. It does not measure the transmission line "standing wave ratio."

N4KGL

Portable Antennas based on hitch mount mast

I have a new hitch mount and 4 foot military mast sections.

Mast on ebay $30 shipped. there are 12 X 4 ft poles  Hitch on ebay $92 shipped

More mount and mast photos

I am trying out various antenna options as shown below.

20 meter Hamstick dipole on 20 foot mast. I also have a 40 meter Hamstick dipole

Par Endfed as an inverted V. This config works 20 and 40 meters.

The Buddistick mounted at 16 feet. I used this config on 40 meters. Uses whole coil so easy to tune by counterpoise which slopes to the ground.

A long wire that is done with the Wireman invisible wire so you can't see it. I used the MFJ 971 tuner and made contacts on 40 and 30 meters.