AA8IA Amateur Radio

Archive for the ‘dipole’ tag

Alpha Delta DX-LB Plus – Part 1 : Arrival

2 comments

Some preliminary babble…

I had mentioned elsewhere on the site that I’d like to have a 160m antenna. I had given consideration to an inverted-L or a Marconi T, but I came to the conclusion that not only would I not be able to create a vertical section of reasonable height but I also would have difficulty extending the horizontal portion as far as it needs to be and have a proper anchor point for it. And if I could manage to secure the horizontal end, it would be facing a direction that I don’t particularly care about. [It is my understanding that there is some bit of directivity towards the direction that the horizontal portion runs from the vertical portion]

I’d lie if I said I wasn’t interested in 160m DX or working working all states on 160m, but now is not the time to do that. I do, however, want to be able to make my presence known on 160m during the ARRL 160m contest and some of the QSO parties that have 160m as an operational band.

Since I have experience with the 42′ Alpha Delta DX-EE dipole, and since I think it is well constructed and has performed quite well for me, I figured I’d throw down the nearly $200 for the DX-LB Plus dipole. This is shortened 160m/80m (shortened) that will also handle 40/15m, with additional parallel wires for 20m and 10m operation. My DX-EE tunes 30/17/12 and I’m hoping I’ll be able to get a match on these same bands with the DX-LB Plus without too much loss.

The dipole arrived and is still packed up. When I removed it from the box I was surprised at how heavy it was. It’s well constructed. The wire is heavy and of course the addition of the inductors makes it even heavier. I suspect that if I don’t manage to get the dipole erected in a way that the two ends are 180 degrees from one another, it’ll probably cause the top section of my Max Gain Systems mast to bow.

I really can’t stand wiring up the parallel wires. And I really don’t want to think about tuning and pruning it so that it’s resonant inside of the CW sweet spots of 160m and 80m, especially since the 3:1 bandwidth is very narrow.

I’m still debating whether I should put this up as a flattop oriented E/W (broadside N/S) or as an inverted V. Either way the center will be @40 feet. If it is an almost flattop, the ends will be at about 30′. If it is an inverted V, it’ll really be rough to have the ends very far off the ground — probably no more than 10 feet, although I’ll strive for 13-14 feet.

As constructed and delivered, it is intended to be fed with coax. However, I do have the option of feeding it with 450-ohm ladderline (~45 feet) into a DX Engineering 1:1 current balun, through an 8′ piece of RG-213 into the radio. If I have too much trouble tuning the antenna, I may opt for feeding it with ladderline as it will make it easier to tune. Of course, feeding it with a random length of ladderline into a balun is not quite the same as feeding it with only ladderline and tuning it with a tuner that accepts balance feedline.

Already I’m losing ambition, just like I did with the DX-EE. It took me three weeks before I ended up putting the DX-EE together since I had to string the additional parallel wires through their standoffs and secure htem at appropriate points. In this case it’s going to be even more difficult since I’ll be dealing with trying to get it to be resonant in a specific small portion of 160m and 80m.

I’ll write more as things progress

Written by Mike

October 14th, 2010 at 3:52 pm

Posted in Antennas

Tagged with , , , ,

HF Station back on the air

leave a comment

Although I’m still working on a decision regarding other antennas for HF, I decided last week to string up a dipole with the help of a friend. It is a 40m diapole in a V configuration. However, it’s essentially a horizontal V because that is my only option at present.

I dragged all of my equipment out of the mothballs and managed to get it all hooked up in a very disorganized way. I bought a Signalink USB from DX Engineering to use for digital modes. So I’m currently using a 20-amp PS, a Yaesu FT-100, the aforementioned dipole and Signalink USB, and an LDG AT-100Pro tuner.

This weekend a few QSO parties were going on including the 7th Call Area QSO Party. I made a single CW contact, almost a dozen SSB contacts, and a few PSK31 contacts.

Jay, N8SJS, encouraged me to get into the digital mode action on HF, which is why I ended up getting the Signalink USB. We hunted down signals this weekend and I made a few more PSK31 contacts and a DominoEX contact. With the help of the PSKReporter website I was able to determine that others were hearing me on the various bands on PSK. This is really handy. Jay conned me into downloading and installing Ham Radio Deluxe, which I was familar with using a few years back. This is a great program for operating the digital modes and has just about every feature known to man in it. It’s a large program suite and taxes a computer a bit, but my laptop handles it with no problem.

I ended up hearing John, AC8JB, pick off somebody on PSK right before I was getting ready to. It was cool to hear another local [he’s from Wellsville] working HF.

Although I realize the pattern of this dipole and its efficiency on the various bands is very unpredictable, it tunes up all the bands I wanted to work with no problems using the LDG tuner and I am able to make contacts. This is great, because now I don’t feel so much pressure to make a decision on other more expensive, cumbersome antennas. I can take my time thinking about what to get next.

I need to get some new coax. I’m using garbage RG8X that is at least 10 years old for HF. I have LMR-400 here and i may put that on. I need to put a coax choke in place to try and curb some RF from coming down into the shack. I also need to get everything set up on a desk and get the station grounded as best as possible.

I have a USB-to-Serial converter ordered so that i can use my serial CAT interface on the laptop [which lakes a bonafide serial port as we all know them]. This will make using HRD / DM-780 that much nicer.

Although thunderstorms were predicted all weekend, we had no T-storms and only had rain. This was great. I really enjoyed this weekend on HF and hope that by next weekend I’ll even have more fun.

Some good sites to monitor DX and band conditions:

DX Summit
PSKReporter
vhfdx.info

Written by Mike

May 2nd, 2010 at 8:26 pm

Posted in Antennas

Tagged with , , , , ,