[TenTec] Value of RX Only Antennas

Rick - DJ0IP / NJ0IP Rick at DJ0IP.de
Tue Oct 1 16:29:29 EDT 2013


Barry, could you back that up with some specifics please?
I don't know what they tested in 1999;  maybe trap tribanders?
If so then yes, of course.

One of the dangers when comparing trap beams to monobanders or beams like
the SteppIR or some of the wire/fiberglass beams is, the trap beams only
show maximum gain near the center of the bands.  Performance drops off
rapidly with the trap tribanders near both ends of the bands.  In fact they
often have only the performance of a dipole on band ends.

The monobanders and the multiband beams with several aluminum elements
(i.e., Optibeam, Force12, etc.), as well as some of the wire beams do fair
well against the SteppIR.  Of course the beauty of the Stepper is its
ability to reverse directions almost instantly.  However if we talk about
reliability, the story changes slightly in favor of beams with no moving
parts.

73
Rick, DJ0IP

-----Original Message-----
From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Barry N1EU
Sent: Tuesday, October 01, 2013 10:05 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Value of RX Only Antennas

Did you mean to say Force 12 and not M-squared?

None of the tribanders they tested in 1999 would hold a candle to a
3-element or larger SteppIR yagi today.

73, Barry N1EU

On Tue, Oct 1, 2013 at 6:48 PM, Jim Brown <k9yc at audiosystemsgroup.com>
wrote:
> On 10/1/2013 7:51 AM, Richards wrote:
>>
>> These receive only antennas are nice to have, but I figure it is 
>> better to improve one's transmit antennas if possible - especially if 
>> one can can replace them with antennas with more gain.
>
>
> RX-only antennas are most useful on bands where it is impractical or 
> expensive to get directivity from your TX antenna  -- 160, 80, 60, 40, 
> and 30.
>
> Another VERY important point. Contrary to manufacturers' claims,  it 
> is VERY difficult to get much more than about 5 dB gain over a dipole 
> with a collection of aluminum on a boom. That was the clear result of 
> extensive measurements by N0AX and K7LXC of a dozen or so of a broad 
> selection of tri-banders.  An M-squared C3 was the best of the small 
> ones, with an average gain of 3.4 dB across the three bands. A Mosley 
> TA33 was only 1.6 dB (loss in the traps made the difference).  An 
> M-squared C-31XR (31 ft boom) was the best of the big ones with 5.3 dB 
> over a dipole, a Cushcraft X9 was 5dB, a Bencher Skyhawk was 4.4 dB, 
> the rest were less than 4 dB, and several big Mosley antennas had negative
gain!
>
> 73, Jim K9YC
>
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