I'm extremely happy with my Force 12 6BA. If you drop off the 40 meter
part of it, you still have a crackerjack antenna, I suppose. That would be
the XR 5 (I have no experience on the XR 5 without the 40 meter part, but I
would think it would perform _at least as well_ on its own).
http://www.texasantennas.com/index.php?option=com_content&view=article&id=92&Itemid=105
Owning it at 65 feet has been a night-and-day difference in my DXing.
That said, I'd vote for height first. Amazingly often (these are very good
conditions right now), I work stuff off the side and off the back of the
antenna, easily, even though I should be (and am) far down in strength
compared to aiming right at the station. And, I think from some of the
non-pileups I work, I can hear stuff many others are not. I know that
stations are way down to inaudible on my Windom at 43 feet. Height is
worth _a lot_.
Larry WO7R
On Thu, Oct 24, 2013 at 8:26 AM, Jim Brown <jim@audiosystemsgroup.com>wrote:
> On 10/23/2013 9:10 PM, Avery Davis wrote:
>
>> TH-11DX at 34 feet?
>> HexBeam at 50 feet?
>>
>
> As to gain figures for these antennas -- around 1999-2000, Ward, N0AX, and
> Steve, K7LXC, set up and measured a dozen or so tribanders on a tower under
> carefully controlled conditions. A few years later, Tom, N6BT, did similar
> work. Both found that the CLAIMED gain numbers for all of them (except
> Tom's Force 12 designs) were wildly inflated, often by as much as 6 dB. Two
> antennas that Ward and Steve measured actually had NEGATIVE gain as
> compared to a resonant dipole at the same point. You can buy a report on
> their work from K7LXC's website. It's $20 well spent. Steve also sells
> N6BT's "Array of Light," which includes his measurements and lots of
> excellent discussions of various antenna designs. I think it was $35.
>
> One of the points that Tom made in his book (really a somewhat
> disorganized collection of essays he's published over the years) is that
> the most efficient antennas are simple monoband Yagis, and that when traps
> are added to cover multiple bands, the traps burn some of the transmitter
> power, and the shortened elements reduce radiation resistance (the part of
> the antenna impedance that accounts for radiated power), which also reduces
> gain. Thus, the gain of an ideal 2-element or 3-element Yagi is the BEST
> that can be achieved by an antenna with the same number of elements for
> that band. The advertised gain figures for the antennas that Ward, Steve,
> and Tom measured were 3-6 dB greater than for the ideal Yagis!
>
> I would look at one of lighter-weight antennas that does not use traps. My
> 3-element SteppIR (the original with no trombones) works very well, have
> been essentially trouble-free for the four years it's been up, and is
> lighter in weight than most other antennas you are probably considering,
> which makes it easier to install safely. It has the efficiency of an
> optimized single-band Yagi on all bands, including the WARC bands. With the
> added fixed 6M element, it's also a very good performer on that band. No,
> it's not cheap, but given your constraints, it's a very good choice. Even
> the simple 2-element SteppIR would be a good choice, and can easily be
> handled by one person. I learned that when I helped N6KJ assemble his for
> Field Day several years ago.
>
> I'd also look at the Force 12 antennas, none of which use traps, and which
> provide very good bang for the buck. The two that Ward and Steve measured
> were the best performers in both groups they measured -- small tribanders
> and larger tribanders.
>
> 73, Jim K9YC
> ______________________________**_________________
>
>
>
> ______________________________**_________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/**mailman/listinfo/towertalk<http://lists.contesting.com/mailman/listinfo/towertalk>
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|