Cramped for space? Need a very portable compact antenna that works DX?
If so, imagine a small beam like antenna with some theoretical gain, about 180 degree directivity, easy to install, direct coax connection, very portable and a price tag at under $50! Sounds too good to be true, right?

While some hams may not agree, I"ll call this design my "one-element horizontal mini V Beam" as that's what they look like! You know, when I get interested in something I just have to see how far I can take it. In this case it's experimenting with MFJ HF vertical antennas as horizontal mini V Beams.

I've had some very good results using CB antennas as V beams on 15 and 20 meters which laid the groundwork for this antenna design (1). Most brands of CB or ham verticals should work on some other ham bands other than the designed band using an appropriately sized whip. You just need to experiment a bit!

This experiment concentrates on the MFJ brand mobile verticals. I used my MFJ 259B antenna analyzer which made testing painless. I highly recommend this economical antenna analyzer for antenna experimenters!

I am very pleased with the performance of the MFJ 40 meter mobile verticals (MFJ 1640T) I used as a horizontal one-element V beam on July 17, 2010 from the Yukon as VY1RST.  The numbers were on previous tests indoors from my apartment: SWR 1.4, R 65 and X 12 and outdoors in the Yukon mounted on a picnic table: SWR 1.1, R 60 and X 0 for a height of about 8 feet! 

Now those are great numbers, but will the antennas perform with those numbers? On 7.205 MHz W6HMB in California and N7EKD in Oregon gave me 57 and 55. They were both 59 with me at 0500Z for a good 10 minutes before the band dropped out. A half hour later I got 5x9 from an AZ station (in my excitement I forgot to log him- he was 5x9+20!) and a 5x5 off-the-side of my V beam from KL2DV in Seward, Alaska!  I was pointed down the Alaska Highway.

Antennas were pruned for 7.220 MHz and worked well above and below that using my LDG Z-100 auto tuner.  The next day I hoisted the V beam up 18 feet high and worked N7EKD again, K6AAX and KL3AB in North Pole, Alaska (he was 55 off- the-back and I was 44!). I was quite surprised on the "off-the-back" and "off-the-side" signal reports received and given! N7EKD said I was louder than last night. The old saying "higher is better" was evident. Wondering if the antenna would also work on 20m, I just had to try. It easily tuned and I worked K6HP with 59 signals both ways. N7EKD and K6AAX were 59+10 and both gave me 55-57 with QSB (I"m running 50 watts). Dialing around I heard the Midwest and South coming in loud, but before I could call, a wind storm had started up so I immediately lowered the unguyed antenna. This was not the first time Mother Nature tried to jinx me in the Yukon, hi hi! All in all, I am very pleased with how easy the MFJ verticals tuned and all the contacts I made in the horizontal position. Here's what I used for my antenna mounts (2).

[40 meter V beam mounted on top of a picnic table using MFJ 40m verticals from Kluane Lake near Destruction Bay, Yukon! Note 20m vertical dipole in lower left of photo using CB verticals and Webster Bandspanner in background.]

[KL7JR's 40 meter V beam at 18 feet high pointed down the Alaska Highway working N7EKD, K6AAX and KL3AB before Mother Nature stepped in!]

Let's try the same idea with a pair of MFJ 20 meter mobile verticals (MFJ 1620T) and see if they are as flexible as the 40m models as used above. I mounted the 20m V beam on a ¾ inch EMT mast about 8 feet long inside the box of my truck. After a few minutes of pruning, test results were: SWR 2.3, frequency 14.200 MHz, "R" 45 and "X" 30. I ended up with a 6 1/2 inch long stinger (that's the entire supplied stinger inserted all the way in to the antenna and 6 ½ inches protruding. I'm sure once I get the antenna higher the SWR and X will come down to the levels I experienced with the 40m verticals but that won't happen from the RV park I'm staying at. I experimented with whip lengths of 6 inches to 8 inches and all had high "X" levels of 30-40. While I had everything set up, I wondered how long the antenna would be when used as a vertical. On 14.270 MHz the SWR was 1.2, with "R" at 50 and "X" at 10 for an overall antenna length of 33 inches making this a very compact antenna for 20 meters.

[20 meter V beam testing from Pasco, Washington.]

From another location the next day, I got the V beam up about 15 feet high in an area free of other objects to see the SWR and X down to lower levels. I fired up my TS-570 only to find S9 QRN and no audible signals. I am confident the 20 meter V beam will work DX as it's 40 meter cousin!

Shown in photo above, here's what I used for my antenna mounts. It doesn't get much easier than that. Hurricane "T" connectors ($4 at Lowes) bent and drilled out to accept 3/8 inch threaded connectors for horizontal or vertical dipole (left) or horizontal V Beam (right) mounting (black coil and wire is for another project). Detailed step-by-step homebrew info is available here for the dipole mount. V Beam mount is the same but one end of "T" bent 90 degrees.

In conclusion, it appears the V beams need to be installed at least 15 feet high above ground, somewhat far enough away from other objects and having a great big body of water nearby doesn't hurt any! The bottom line, MFJ HF Mobile HamTenna Whips, available for 6 through 75 meters, are economically priced ($19.95 each, 2010 price) heavy duty compact mobile antennas that perform well, especially outside their intended design! If you work me in 2011 from the Dominican Republic (HI8/KL7JR), Hawaii (NH7DX) or the US Virgin Islands (WP2JR), I'll be using these antennas!