Tag Archives: antenna tuner

Launching The Loop Skywire

Back in early October I finally strung an HF antenna here at the Kansas QTH. The antenna was a RadioWavz End Fed Zep. The performance was mixed and I never did get it to load on 75M. I am a believer in the magic of a dipole (132′ fed with ladderline). But the geography of the Kansas QTH would really only support a dipole running east/west and radiating north/south… not what I wanted. The End Fed Zep was a compromise allowing me to make the antenna run north/south and radiating east/west. As I said, the performance was lacking. In comes the Loop Skywire. A past QST article talks about setting up a horizontal loop: The Skywire Loop, November 1985.

The author, Dave Fischer (W7FB) avoids theory and talks about just the specifics of construction and antenna performance. The basic principles of setting up the horizontal loop include its horizontal position over ground and maximizing the enclosed area within the loop. Ideally, the loop is installed as a circle – but reality tends to make it look more like a square… a compromise between number of skyhooks/antenna wire supports and maximum enclosed area. Ideal height above ground is 40 feet, but the higher the better. Like most wire antennas that you try to use beyond their fundamental harmonic, it is recommended you feed the loop with ladderline to minimize feedline loss. To determine the length of wire required for the loop divide 1005 by your fundamental frequency in MHz. If you set up a loop for 80M, it should also provide good performance from 80M up to 10M. The loop should radiate omnidirectionally and greatly minimize local RF noise. It’s low take off angle also supports good DX performance.

At the recent hamfest I went to in Kansas City, I purchased two 150′ rolls of #14 flex-weave copper antenna wire as well as a few 100′ rolls 3/32″ black Dacron rope. From MFJ I had a 6-pack of ceramic insulators. I had about 75′ of 300-omh ladderline as well as a ladderline feedpoint insulator. Along with my CVS19 Pneumatic Antenna Launcher – I was ready to fly this skywire.

Installation took all afternoon, but the weather was great and I took my time. I ended up with 6 antenna supports, trying my best to make it as circular as possible. My CVS19 Launcher continues to perform well. My bicycle pump broke so I switched to the 12v roadside tire pump in the XYL’s emergency auto kit. This made for a quick turn around for prepping the CSV19 for successive antenna wie support lines. Setting up most of the ceramic insulators as “floating” allowed me to apportion the copper wire as needed around the loop. In the end, my loop was a bit less than 300′ and had the shape of a long oval rather than a square (or circle).

After connecting a 4:1 voltage balun to the ladderline and running coax to my LDG AT-200 Pro tuner I was on the air. My first observation was that the antenna was very quiet. Were previously I had S3 to S5 background noise, the noise floor dropped to S1 or in some cases was completely gone. The loop tunes easily from 80M to 10M.

Another indicator of success – a 20M QSO with my dad, KD6EUG, in California. A goal that has been on my list for almost a year. I was also able to work stations in British Columbia, Maine, Michigan, and Oklahoma. There are still a few more adjustments I want to make on the loop, but so far I am pretty happy with it and look forward to seeing what more it can do.

I guess now I need to make a QSL card for the Leavenworth, KS QTH so I can send one to KD6EUG.

On The Road Again!

It was good to get back behind the wheel of my 2005 Toyota Tundra – although can’t say I am excited about paying to fuel it up. I’ve attempted to get a good HF install for mobile operations before experiencing limited success… with perhaps my biggest rookie mistake being an attempt to use the ICOM AT-180 autotuner along with my IC-706MKIIG.

I used Hamsticks and Hustler mono band resonators – it worked pretty well but I got tired of having to exit the vehicle every time I wanted to change bands.

My answer was to install a screwdriver antenna. I’d been planning this mobile install for some time, using lessons from my trials in the Spring of 2007 as well as a significant amount of reading and research (eHam, WorldRadio, CQ Magazine, websites). I decided on basing my mobile install around the Tarheel Model 75 “Stubby” providing continuous coverage from 3.7 to 34 MHz. The folks at Tarheel worked with me to get me going – responsive to my emails and questions.

The radio for this mobile install: my ICOM IC-706MKIIG. I’d originally purchased this radio when I arrived in Hampton back in the early Summer of 2005. The purchase was in part to motivate me to upgrade from Tech to General – which it did. That Summer I passed the written exam (Element 3) at a nearby hamfest for General. But I was not yet ready for the Morse (Element 1). It wasn’t until later that Fall that I was ready for the Morse… and barely passed too. I’ve been very pleased with the IC-706MKIIG; it is a great radio for a beginner, easy to operate, solid performance, flexible to use either in the radio shack, portable, or mobile.

To mount the antenna to my Toyota Tundra, I really did not want to permanently mar the exterior of the truck. I’d admired K4GUN’s install and thought his implementation of using the Geotool stake pocket on the bed of the truck was brilliant. I wrote Steve, K4GUN, concerning his install and he provided some great additional information concerning the challenges of the stake pocket mount. After working with Rick, WA6JKH, to ensure I was ordering the proper mount, I placed my order and Rick gave me a nice active duty military discount.

I decided to get N2VZ’s Turbo Tuner for ease of operation. Operating HF while driving is already complicated enough and I wanted to make tuning the antenna as easy as possible. Bill was very responsive and also provided a military discount.

I had ordered all the equipment while in Iraq, so everything was waiting for me when I arrived home.

The install took two days. Perhaps the hardest part was mounting the IC-706MKIIG under the passenger’s seat. Already installed under the seat was my ICOM IC-208H – my trusty VHF/UHF rig. I’d originally installed this rig during my circumnavigation of the continental US back in 2005. During that install, I only partially removed the passenger’s seat. This time I pulled the seat completely out of the truck which greatly helped me successfully position both the IC-208H and the IC-706MKIIG in the limited space.

Routing the feedline from the rig to the stake pocket mount was fairly easy, making use of the rubber grommet directly under the passenger’s seat and zip ties along the feedline’s path to the rear of the truck. Soldering the connections to the stake pocket mount was straight forward but it was a bit tricky feeding the line up through the bottom of the stake pocket.

Setup of the Turbo Tuner was a snap; I followed the provided instructions step-by-step, making sure I had the DIP switches positioned properly.

Mounting the antenna onto the Geotool stake pocket mount was made easier by using the HI-Q’s Giant Quick Disconnect. Payment was via PayPal and Charlie, W6HIQ, had it on my doorstep within the week. Thanks Charlie!

How does it work? So far, so good. More reports from the road are coming… and maybe a picture or two.

gerryk – Bringing tech to the West

http://blog.gerryk.com/

Nice new blog… and I really enjoyed this post:

First proper HF QSO
July 21st, 2007

Now I have a proper dipole up, albeit not all that high, at about 15ft, signals are coming in very strong on all HF bands. Now that could mean a great antenna and matcher on my part, or, is more likely, a mediocre antenna system but huge signals from stations with massive beams and amps in the 100w plus range.

Going on what I was hearing today, though, it seems to be a combination of the two. I heard plenty of 100 watt, G5RV at 60ft people, as you might expect, but also a few putting small powers out, like one gent putting 30w into a random wire who was chatting to another putting 5w into a resonant dipole. Both were 5/6 to 5/8 which boosted my confidence no end, given that my max output with the FT817 is 5w. I listened around the 40m band and, ok, it wasn’t completely crowded, but there was plenty going on all the same. I listened into a few chats and whenever I heard one wrapping up, got ready to pick up the open station after the other went QRT.

Time after time, I waited for a QRZ or CQ and went straight back with my call, but when I unkeyed, generally heard a booming 5/9+ signal, or, more commonly, a few, coming back to the calling station, drowning my little signal completely. Frustrating, you might think, but, to be honest, I enjoyed tuning up and down the band, listening not just to people ragchewing or notching up QSOs, but the atmosphere too. The weather has been almost tropical of late, by which I mean tropical rain rather than tropical sun, and that sort of weather means thunder. Not thunder I could hear with my ears, unless you consider the added hearing aid of about 66ft of wire hanging about 15ft in the air. With that to pick up the discharges, the thunder sounded like feet crunching in gravel, in amongst the ever present hiss.

I didn’t spend a couple of hours throwing rocks into the branches of trees just to listen to clouds blowing off steam, though, I did it to talk to people far away with a tiny amount of power, and in among the big guns it just wasn’t happening. I tried tuning down to the 80m band, but apart from some very weak signals, it was dead as a morgue. I tried 20m. Not anywhere like 40m, but a few here and there. I tried catching loose stations at the end of a QSO, but again and again was rendered inaudible by what one QRP op called a pocketbook op. Those with deep pockets rarely have problems being heard, but, a well placed whisper can be like a shout, so I stick to my rather small guns on the power output. I tried 15m, and it’s pretty silent too, until, up at 21.190MHz I hear a clear voice calling CQ 15! He repeated his call a number of times while I frantically rematched the dipole with the Emtech ZM-2. Finally got a nice low SWR, switched back to USB and heard him still calling CQ. I keyed up, and as slowly and clearly as possible gave my callsign. “QRZ? QRZ, that station.” he said, and I was in. I repeated my call, almost shouting it into the mike. “Echo India 8 Delta Foxtrot Bravo?” he replied. I reread my call, “Echo India 8 Delta RADIO Bravo, Echo India 8 Delta ROMEO Bravo” and this time he got it. “EI8DRB from Charlie 3 3 Portugal Panama” he returned, mixing up the phonetics as hams often do. He gave his QTH as Andorra and his name as Pedro. Andorra! That’s nearly a thousand miles away! On 2.5w and a dipole 15ft off the ground, surrounded by trees, that’s not a bad achievement.

He gave me a report of 3/5 and I gave his as 5/5, we bade each other good DX and 73 and went about our business. He also said I could QSL via QRZ.com, and within the next few days, Pedro in Andorra will be getting a postcard from Galway confirming our brief QSO. I don’t think he fully realises the significance of this to me. To him, I was just another weak station for him to log, for me, it is the beginning of an adventure.

Cleveland, OH to St. Louis, MO

Another long day and lots of rain. I left the hotel in Cleveland around 8:15am and found a place to park near the Rock & Roll Hall of Fame and put my antennas back on. I put on the 40M Hustler to see if it would make a difference with the problem I was having with the Icom AT-180 tuner. I rolled out and tested the radio with the Hustler antenna but encountered the same problem as before.

I headed over to the AES store in Cleveland. The store was well stocked – equivalent to what I’ve encountered in an HRO store, although I think AES had more magazines and books. I purchased an Icom AH-4 longwire tuner and a LDG 4:1 balun.

Back in the parking lot I disconnected all the cables on the AT-180 and then reconnected them. That seemed to have fixed the problem…. because 40M started working without issue. I had a nice QSO with Stan, W??JMV, who was operating from his attic radio room on the Jersey shore. I then checked into the ECARS net, the NCS had a nice solid signal. I then worked 20M talking to England, Serbia, Czech Republic, and Italy.

When I was about 5 miles east of St Louis a tremendous rain started coming down – I had to pull over on the side of the highway. It was the worst downpour I’ve ever seen. Tomorrow should be an easier drive.

Hampton, VA to Cleveland, OH

I left yesterday at about 10:20am, having done a poor job packing and generally having any semblance of organization. I ended up dumping a lot of extra stuff in a footlocker, piled everything in the backseat of the truck and headed out. Not more than a few feet out of the driveway I answered a CQ from Andy, W2QIQ. Andy has been a ham for 66 years (as opposed to my 6 years). He served in the Army during WWII in Europe, starting in Egland, making his way through France and ending up in Berlin.

My radio started acting up on 40M. I was using my Workman Hamstick tuned for the 40M phone band. The Icom AT-180 gets a good match right away bringing the SWR down to a 1:1. But then after I’m transmitting for about a minute, the Tune light flashes for about 10 or 15 seconds and then the Tune light shuts off and the power drops and SWR goes up. My first guess is that the radio and tuner need to have a better ground. But the matching impedance range for the AT-180 is only between 16 and 150 ohms, so that could be the problem. This is only a problem on 40M.

My TH-D7A APRS kludge seems to be working well when there is a digipeater. When I was on I-77N coming across the West Virginia/Ohio border, I accidentally pulled one of the power leads. I didn’t really notice it because all through the Smoky Mountains the APRS coverage was nonexistent. I got a few hits through Charleston, WV and then it (maybe) tapered off after Charleston or maybe I had pulled the power. When I was approaching Canton, OH, I knew something had to be wrong, because it was such a large area it would have to have a digipeater. That’s when I noticed the power was disconnected. I reattached the power and there was tons of APRS traffic.

Had some nice QSOs along the way: KL7GKY, EB7xx, YU1XA, and KB5YAY.

More on the mobile install

I spent some more time on Sunday improving my HF mobile install. After completely removing the rear interior panel of the cab and finding no grommet or any other easy method of passing the feedline into the cab I was able to find a nice sized grommet under the passenger seat. I was able to keep the feedline to a length of 10 feet, ran it through a plastic covering for protection, and then tied it off underneath the truck at multiple points using zip ties. For the antenna mount support, I found an L bracket at Home Depot that I was able to securely bolt to the bed of the truck near the cab. I ran a short length of braided grounding wire from the other side of the bolt (inside the bed frame) down to the frame of the vehicle underneath the cab. For the antenna mount, I’m using a 3/8 inch X 24 Radio Shack base fitting – standard for use with Hamstick, Hamstick knock-offs, and the Hustler varieties. The base fitting fit neatly through a pre-drilled hole through the top of the L bracket.

In the past when I operated portable HF from the truck I used one of the 12v convenience outlets (aka cigarette lighters). I have consistently failed to locate any easy access through the engine firewall for a power cable. Now with finding the grommet under the passenger’s seat, I decided to use that for the entrance for 12v power. I used 10 gauge wire from the truck’s battery terminals (both with in-line fuses), routed the cable around the engine and down the passenger side to the grommet. I terminated the line using Anderson PowerPoles and am using a Saratoga Amateur Power Panel for distribution.

I took advantage of the IC-706MKIIG’s detachable faceplate, using the mounting kit to attach it to a Belkin iPod/PDA holder that secures into a cup holder. This allows me to easily tune around the band with my right hand without any reaching. The handmike attaches to the faceplate.

I haven’t found a great place to actually secure the radio and auto tuner. Right now they’re tucked under the rear of the front passenger’s seat. The seat immediately behind the passenger’s seat folds up towards the front of the truck and provides protection (and shade) for the rig. If I can find a way to mount the radio that still allows me to quickly and easily remove it for portable use, I’ll do it.

For antennas I’m using a two Hamstick knock-offs made by a company called Workman. One is for 20M and the other is for 40M. They easily screw into the 3/8 inch X 24 base fitting. Both work well, the 20M tunes the entire band and the 40M tunes nicely below 7260. I also purchased a cross between a Hustler and a Hamstick antenna (also for 20M and 40M) made by a company called Opek at the Virginia FrostFest last month. The 20M antenna is worthless. It won’t tune anywhere in the 20M phone band. The 40M antenna does a nice job covering the 40M band and tunes up to 7290 without issue. I also have a 75M Hamstick (can’t remember where I bought it) – with a little trimming of the stinger I was able to get the stick to tune the upper portion of the 75M phone band. The tuneable bandwidth for the 75M stick will be narrow, no way around it. But I can cut a few different length stingers to provide coverage down into 80M.

I’ve had successful QSOs using the Workman 20M and 40M antennas as well as the 40M Opek antenna. This evening I had the 20M Workman antenna mounted and first had a QSO with PS7JS in Brazil. There were several stations calling, but PS7JS came back to me after my second call and gave me a 59 report. Ten minutes later I had a QSO with Pedro, XE1REM, operating from Mexico City. Pedro also gave me a FB 59 report. Earlier today I had a QSO with a station in Slovakia, receiving a 57.

A couple of notes on operating mobile:
(1) I need to get something to take notes with. I need to be able to jot down callsigns, freqs, and times.
(2) I have to remember to include “mobile” after my callsign.

Sunday in the shack

I was successful in transferring the WX station duties to the computer out in the garage. I first had to get the Davis Weather Monitor II talking with the computer – which was accomplished after I changed the COM port speed to 2400 baud. I then transfered all the Weather Display files from the computer in the radio room out to the garage. The Weather Display software started up, green lights indicating that it was taking data from the Davis Weather Monitor II. But I didn’t have any sensors plugged in yet, so the only data being displayed was the indoor temp (now the garage temp) and the barometer. The outdoor temp sensor is located near the garage, so I was easily able to reroute the cable into the window of the garage and connected it to the Davis Weather Monitor II box. The outdoor temp came up right away. The next challenge was setting up the FTP for my weather webpage. The Weather Display software has great wizards that walk you through setting up different aspects of the software – the FTP setup had such a wizard. And now the webpage is getting updated every 5 minutes. Great! I still need to (1) reroute the wind direction and speed cable to the garage (requires me to get on the roof), (2) find some place to put the rain gauge (may require me to get on the roof), and (3) get the webcam hooked back up.

Spent some time cleaning up the radio room. I finally unpacked the MFJ-989C tuner that I got to go along with the Heathkit SB-220 amp. Neither are setup – that’s a project for another day.

I was also able to make contact with MI3JQD, operating from Northern Ireland… and a CW contact on 30M with John, K9??? in Indiana.