[Elecraft] dBd vs dBi

[Bob Nielsen]

This is probably getting a bit off-topic, but does anyone have a link
for RS-329?  Google got me to a couple of sites which provide copies of
standards (for $$), but a search for RS-329 yielded nothing.

Bob, N7XY

On Sun, Oct 20, 2002 at 01:53:07PM -0500, George, W5YR wrote:
> While I agree with the first part of Earl's statement quoted below, I
> believe that under certain circumstances, ARRL will in fact publish gain
> figures, etc.
> 
> The following is taken from the ARRL website:
> 
> "Antenna advertisements that specify gain, front-to-back ratio, or
> beamwidth are acceptable if the antenna has been tested in accordance with
> EIA Standard RS-329, Part 1,
> and a statement to this effect appears in the advertisement. Certified test
> results must be submitted with the ad. 
> 
> "In lieu of RS-329-certified results, the advertiser may advertise
> performance figures derived from specific antenna modeling programs. To do
> so, the advertiser should first
> model the antenna, using either YO (Yagi Optimizer, for Yagis only) or the
> latest version of the NEC (Numerical Electromagnetics Code) program. See
> the ARRL Guideline
> for Modeling Antennas for Advertising Acceptance for answers to frequently
> asked questions and for sample graphs. The data files used must be
> submitted to ARRL at the
> time the advertisement is submitted. 
> 
> "All advertising performance claims derived from antenna modeling must
> indicate that they are calculated. As a minimum, we expect to see the peak
> free-space gain (in dBi
> referenced to isotropic) at a manufacturer-specified frequency. ARRL
> encourages advertisers to provide even more information to end-users,
> showing performance
> measurements or computations over a specified frequency range, rather that
> at a single frequency. 
> 
> "In addition to free-space performance figures, advertisers may wish to
> show computed performance over ground. If so, they must use a "typical"
> ground, with a conductivity
> of 5 mS/m and a dielectric constant of 13. They must invoke the
> Sommerfeld/Norton ground model if NEC is used, and the terrain shall be
> flat ground at antenna heights
> specified by advertiser. 
> 
> "Advertisers may elect to show a computed front-to-back ratio at a
> frequency they specify. However, ARRL encourages advertisers to show the
> worst-case front-to-rear ratio,
> over a frequency range of their choice, preferably a complete amateur band. 
> 
> "ARRL also encourages advertisers to grant permission to place modeling
> files on the ARRL BBS for knowledgeable users to try for themselves, to
> foster greater public
> confidence in performance claims. As always, the ARRL Laboratory reserves
> the right to inspect and test an actual antenna to verify modeling claims."
> 
> I am pleased to see ARRL adopt this enlightened policy regarding antenna
> ads rather than avoiding the issue altogether. 
> 
> 73/72, George    
> Amateur Radio W5YR -  the Yellow Rose of Texas
> In the 57th year and it just keeps getting better!
> Fairview, TX 30 mi NE of Dallas in Collin county EM13qe
> K2 #489      Icom IC-765 #2349     Icom IC-756 PRO  #2121
> 
> 
> 
> k6se@juno.com wrote:
> 
> > Be skeptical of any manufacturer's gain claims they give in their specs.
> > Unscrupulous claims of antenna gain is why ARRL will not publish gain
> > figures in QST ads.
> > 
> > Some claims are honest, while many are not.
> _______________________________________________
> Elecraft mailing list: Elecraft@mailman.qth.net
> You must be a list member to post to the list. 
> Postings must be plain text (no HTML or attachments). 
> See: http://mailman.qth.net/mailman/listinfo/elecraft
> Elecraft Web Page: http://www.elecraft.com

-- 
Bob Nielsen, N7XY                          n7xy@n7xy.net
Bainbridge Island, WA  
IOTA NA-065, USI WA-028S