November 11, 2009.
Still only 25 radials down. Need to do some more before winter sets in.
Antenna seems to do OK. On 160 meters I've worked Hawaii, Alaska, TX3A in the Chesterfield Islands, and XR0Y on Easter Island. The TX3A QSO only required 3 hours in pileups -- one two hour stint on the second day that they were on 160 and a one hour stint a week later. First tries resulted in at least one "WA0?" reply. Second got a confirmed QSO. XR0Y only required half an hour or so. So I guess it gets out. The ARRL 160 meter contest the first weekend in December should prove interesting.
The December 2009 QST has an article on a simple matching network for 43-foot verticals on 80 and 160. Since I'm currently only using the antenna on 160 I've ordered the toroid and will try this. I expect that it will radically improve performance. At some point I'd like to put in a remotely-controlled matching unit for all of 160 and 80 meters but that can wait. Would be nice to have this antenna as the 80 meter antenna for the second radio during contests.
June 15, 2009 8:45 a.m.
Put another 4 easy radials in -- one from the first 20 field and 3 from the second twenty. Going to run out of radials before the shipment arrives. Antenna tunes a bit differently but still acceptable on the tuner settings. Haven't really noticed any difference in the ground-wave signals I hear every morning.
June 13, 2009 8:35 a.m.
Decided yesterday to go with 40 radials and ordered another 20 radial kit along with a bunch of tinned braid to upgrade the ground connection to the BigIR
Ran three more radials, for a total of 13 now, this morning. Two were difficult and one easy.
The first difficult required 45 minutes, some forestry, and three bleeding scratches on my arms. But it is in and it was probably the most difficult -- I hope. The next difficult just required moving the remains of the dead tree that was cut down immediately after raising the antenna.
Since I'm doing another twenty radials after this I put in an easy radial in the second set. I think I'll continue this pattern until finished -- two difficult and one easy. Granted it will take a few more weeks to finish but I really don't need everything finished until the snows arrive in November -- although I'd like to be pretty well finished by mid August for the NCJ QSO parties where 160 meter contacts are additional multiples.
Funny thing -- the second set of radials are going to be easier than the first. This was the unfortunate outcome of the antenna positioning required to allow lowering the antenna without encountering any trees and electing to run the radials the same direction as the guy wires. So having decided to do the second set I've a bunch more easy radials for days when I'm particularly lazy.
On a slightly ominous note, just adding three radials has changed the antenna tuner settings so that both capacitors are a maximum when I reach zero reflected power from the tuner. If this gets worse the plan is to modify the MFJ to add a couple of hundred picofarads of capacitance to the transmitter side of the tuner. This will make the antenna and tuner 160 and 80 meters only but that is not a big concern. Hopefully this will not have to be done.
June 7, 2009
First QSO with the antenna. Heard W5KDJ calling CQ on 1.808 mHz RTTY this morning. He was about S6 on the meter. Called barefoot and he came right back with a 569 report. He is near Houston which is a little over 700 miles from here so this isn't a bad outcome at all considering that I've only worked NM, CO, and AZ on 160 meters from Taos in the past.
Did discover a net on 1.912 running AM. Was really tempted to try the rig on AM. Will read up in the manual before doing this. The guys had big signals but after looking them up in qrz.com I discovered that at least a couple of them were running surplus AM broadcasting transmitters. Not sure that my pipsqueak 50 watts of AM would even be heard!
Got energetic later in the morning and installed four more radials. The total is now ten and that means I'm half done with this round. Unfortunately the remaining radials are going to be a lot of work. Going to have to fish wire under trees and shrubbery.
June 6, 2009
First thing in the morning I listen around. I find two or three "nets" on LSB with stations with 250-300 miles from Taos. I just listen as these are "good ole boys" nets and I'm obviously an outsider.
After it warms up a bit I install two more radials. Unfortunately I'm running out of easy radials to install and will need to buckle down and route some wire between trees. That can wait until tomorrow.
Listened in the evening but didn't hear much. I have a feeling that the only time there is lots of activity on 160 is during contests and even then during the winter. Gives me lots of time before I need to be finished installing the radials.
June 5, 2009
We're back in town. I raised the antenna and began compiling a chart of antenna tuner settings. It quickly becomes apparent that the tuner will easily tune the antenna on 160 or 80 meters. I used the suggested high impedance settings from the tuner book. I have noticed that the MFJ SWR indication doesn't necessarily exactly follow the SWR indication in the transceiver.
Don't hear much in the evening. I do a rough comparison receiving 75 meter phone between the DX Engineering antenna and the BigIR. No obvious difference in received signal. I'll wait to try any real transmitting checks until all of the radials are down. With only four radials the DXE has no chance.
May 28, 2009
Still muddy as all get out but not so much so that I can't work. I trek everything -- including a chain saw -- down to the installation still. Almost immediately there is a problem. The two rocks that were used to keep the pipe vertical are attached to the concrete. One is easily removed. The other cannot be kicked away and it is in the way of the radial connection plate. Application of a sledge hammer disintegrates it leaving a small piece in the concrete that is no problem whatsoever.
I attached the radial plate, using Anti-Seize compound on all of the bolts. I really hate this stuff. It gets everywhere and although it does wash off the hands it takes some work. I do make a small mistake and install the plate a big too low. I'll fix this sometime when the weather is better.
I had already built up the antenna into four sections. The instructions have you build the entire thing from the ground up but that seemed kind of unwieldy. In addition the fit between the second section and the first and third sections is very tight. So I elected to speed things up and several weeks ago I assembled four pieces of four sections each. I also mounted the bottom section to the insulator and mounting plate.
I installed the mounting plate on the pole and then the bottom section to the mounting plate. I then tilted the antenna over onto a sawhorse and attached the other three sections. This went well and I was glad that I had pre-assembled many of the sections.
While the antenna was tilted down I attached the unun to the antenna. At this point I discovered that I had placed the antenna in the insulator ninety degrees wrong with regard to the placement of the feed point connection. Fortunately this was easily resolved and I connected the antenna to the "+" terminal of the unun The ground connection will wait until the antenna is vertical.
After a brief break doing calculations with a spreadsheet, I attached four pieces of Dacron rope 33 feet long at the top of the eight segment -- approximately 21.7 feet up and half the length of the antenna as recommended by DX Engineering. I then raised the antenna, planning on connecting the guys.
It was then I noticed that a nearby dead tree -- we have many dead piñon trees in the area due to bark beetle infestations in the past -- was already rotted at ground level on the stump and ready to fall at anytime. I had anticipated trimming this tree with the chain saw to accommodate the guys. Now I can see that in the near future the tree will fall and probably take down the antenna. So I took a break from installation and cut down the tree.
I have tried to use screw-in anchors in this soil in the past and it is virtually impossible. So I purchased some Duckbill anchors from a forestry supply. This are driven into the soil and can easily support the minor loads needed to keep the antenna from swayed excessively. I position the four guys, pound the anchors in, and guy the antenna. Works like a charm.
I connected the "-" terminal of the unun to the radial plate and connected the coax to the unun. At this point I debate testing the antenna but decide I'd better at least have a few radials. I connect and extend four 65-foot radials. At this point it starts raining so I gather everything up and head for the house. Since I'm traveling for the next week there is definitely not time to put down the other sixteen radials.
The big concern with this antenna (other than coax loss issues) is whether the antenna tuner will actually tune it. With some trepidation I fire up the rig on 1.825 mHz and try to tune it with the MFJ 989D tuner. To my surprise it tunes quite easily. The antenna seems to receive OK -- it really picks up noise anyway -- so I take a break for lunch.
After lunch I decide to do some more tests. But I find an S9 noise level. Turns out it receives just fine -- particularly when there are thunderstorms within thirty or forty miles of the location. Obviously I'm not going to be able to work anyone so I get out in the rain and lower the antenna so I won't have to worry about lightning while I'm out of town.
Remaining tasks when I return are running more radials and doing a bunch of forestry work so that I can lower the antenna without disconnecting three guys. But at least the antenna loads!
May 27, 2009
Today we dig the posthole and install the mounting pipe. The pipe is 4 feet of 1 1/2 inch galvanized water pipe which has an outside diameter of 1.9 inches and is perfect for this application. It will be put down 28 inches into a 8 inch diameter hole and then the hole filled with concrete. After considering digging the hole by hand we have decided to rent a power posthole digger. We decide on the one-man version that digs a hole eight inches in diameter.
My associate, Tim, arrives with his son, a bunch of hose to use in mixing the concrete, a wheelbarrow, miscellaneous shovels, a manual posthole diggers, and the power unit. With the power digger we envisioned a very quick process.
We were wrong.
Turns out the digger probably needs a new bit and the ground is 18 inches of clay that is like plastic. I get the digging bar and we alternate using the digging bar, removing dirt with the clamshell posthole digger, and the power unit. It takes about an hour but we end up with a nice hole 28 inches deep. We put the pipe in, fill the hole with concrete and then use two large rocks to keep the pipe properly vertical while the concrete sets.
Tomorrow I build the antenna which should be a simple task for one person.
May 23, 2009
Since everything arrived it is time to get started on the installation. The weather has been very wet with daily rains which has delayed beginning the installation. First task is to fish the coax for the new antenna into the shack. Unrolled two hundred feet of Buryflex (a high performance RG-8/U with weather and UV proof jacket – a little stiff due to solid center conductor), and threaded it through the trees to the conduit going into the shack. This is a one or one and one half inch plastic electrical conduit that travels underground about 5 feet and then turns ninety degrees and runs inside the wall up to the second story – maybe ten or eleven feet up. The conduit already had one RG-8/U, one Buryflex, and the two control wires (4 wires each) for the BigIR vertical. My eyeball analysis had said that there was room for the additional cable but of course all of it would have to be pulled at once. So I tied a Dacron rope onto the control wires and pulled the whole mess from the shack outside. That wasn't too tough. I then tied and taped the various cable together with the relative lengths that I wanted them to have in the shack and started pulling. When the electrician installed the conduit I had him put an access point/junction at the top of the run with a straight horizontal into the shack. So I’m standing seven feet up on a nine foot ladder pulling straight vertical – and scrambling up and down the ladder to force-feed the cables from the beginning of the conduit. Got about half done and it started to rain. I was so hot and sweaty by then that I was ready to take a break so I went in and cooked some lunch. By the time I was finished the sprinkles had stopped so I pulled the rest of the cable up and then threaded it the short distance into the shack.
The remainder of the installation awaits digging the hole.
May 3, 2009.
I have wanted an antenna for 160 meters for several years. In fact, at one point, I had the 160-meter coil attachment for the Hy-Gain DX-88 that melted down on 80-meter RTTY one contest morning. The DX-88 installation with a gigantic base loading coil and only 16 fifteen-foot radials was pretty disappointing. I've also used a 135 foot dipole fed with open-wire line. That was reasonably effective with the center at 35 feet above the ground -- at least for contacts within a thousand miles or so. But the location in New Mexico doesn't have any convenient tall trees and I don't want to spoil the view with a big tower so that option is not attractive. In addition, in order to get low angles of radiation with practical heights verticals are pretty much a fact of life on 80 and 160 meters.
Antenna "experts" tend to be down on vertical antennas in general and shortened verticals in particular. Being purists what they fail to understand is that virtually all antenna installations involve compromise, be it with regard to price, size, aesthetics, performance or some combination of all of these factors.
I considered an inverted-L type antenna but again, I have no way to get the vertical portion high enough to be effective nor do I want to have another, equally tall, vertical support a hundred feet away. Aesthetics discourage a large capacity hat on the shortened vertical. The one piece of good news is that there is lots of room for radials although running them through scrub oak and piñon forest isn't the most pleasant task in the world. I finally decided to install a DX Engineering MBVE-1 "All band" vertical. In my limited experience a lot of vertical installations are disappointing simply due to lack of sufficient and long enough radials. I consider 15 1/8-wave radials an absolute minimum.
The MBVE-1 is a tapered 43-foot aluminum tubing vertical. I put the notation regarding all-bands in quotes because there is nothing whatsoever in this antenna making it operate on any particular band. In fact, the length is chosen to not be resonant. Rather it includes a 4:1 unun transformer and any matching is done with an antenna tuner at the shack.
The "experts" are all over the map in criticizing this antenna. They criticize ground loss -- a factor in any vertical and more serious in this one simply because the ground resistance is a larger component of the oeverall equation. They insist that the inherently high SWR in the coax will produce major losses but ignore the fact that any shortened vertical that has loading, whether at the base, center, or top will also have losses. They point to the losses in the antenna tuner but any antenna on 160-meter (except possibly a full quarter wave vertical) will have to have some kind of tuner in the shack (or at the base of the antenna) because of the narrow bandwidth of the antenna.
I have worked DXCC on 80 meters using a Butternut HF9V with 16 15-foot radials. I currently use a BigIR on 80 meters which is a 33-foot, base-loaded vertical with a broadband internal matching transformer. I use 30 fifty-foot radials with this antenna and I get lots of "big signal" reports -- even from DX stations. My gut analysis says that a 43-foot vertical with 16 60-foot radials should be at least as effective on 160 meters as the HF9V was on 80 -- and possible somewhat better as the radial system is a huge component of performance and the radials would be twice as long (for the wavelength) as the HF9V radials were. If the coax losses using only the unun at the antenna prove to be devastating, then I will put a base loading coil at the antenna, switch to a 1:4 or higher ratio unun, and have a base-loaded vertical.
Installation Plans
I have purchased the antenna, 4 Duckbill tree anchors, a couple hundred feet of dacron rope, and 20 pre-prepared 60-foot radials. I need to find a 4 foot length of 2 inch OD thick wall galvanized pipe. Hopefully Lowe's will be able to supply this.
I will dig a 2-foot posthole in our rocky soil through the use of a manual posthole digger, a "digging bar", and copious amounts of water. This will probably be the most strenuous task in the entire installation.
It will be necessary to use a chainsaw to "modify" some of the piñon and scrub oak in order to attach four guys to the antenna. These are necessary to prolong its life in our frequent gusty winds. Although those winds are not high enough to destroy the antenna they produce long-term fatigue effects that have pretty much destroyed two previous verticals.
Because of the rocky soil interspersed with heavy clay, conventional twist-in anchors cannot be set. For the BigIR I tried Duckbill tree anchors. These are easily pounded into the ground and seem to work great to hold the BigIR guys. One of the guys will need to have a quick-release capability to allow lowering of the antenna on its tilt base. This should be simple to implement.