[VHFcontesting] uWave Contest Rules Question

k9tms at mindspring.com k9tms at mindspring.com
Fri Aug 11 16:13:30 EDT 2006

Good point, but how do you account for the better signal strength you get
from your antenna being 40 to 50 foot in the air as opposed to 1 foot? At
10 Ghz that 1 watt 50 foot up will go much further than 10 watts at say 5
foot. Of course then there is the other possibility that you have remote
mounted your transverter at the antenna and your transverter and antenna
maybe at 150 foot, how do we account for that? 

Bottom line here is just how many contest rules and entry categories do you

Tom - K9TMS

> [Original Message]
> From: <kr7o at vhfdx.com>
> To: <vhfcontesting at contesting.com>
> Date: 8/10/2006 5:09:50 PM
> Subject: Re: [VHFcontesting] uWave Contest Rules Question
> I may regret stepping into this one.  First off, this clearly shows the 
> problem with entry classes based on output power.  ERP is a much more 
> equitable (uh-oh, here it comes) evaluation of station performance than 
> output power.  While 10W may be QRP at VHF/UHF it definitely isn't at
> and most microwave bands.  Likewise, 10W into W5UN's MBA is not QRP 
> either.  Since ERP includes all external system gains/losses it is also a 
> fair indication of RX performance (neglecting the performance advantage
> mast mount preamps).  ERP is not that difficult to calculate and if a 
> operator has done their required RF exposure calculations, one should be 
> capable of performing ERP calculations.
> Now, since most contest sponsors aren't on board with ERP based entry 
> classes, things become interesting.  As Ev states, output power is 
> "Traditionally, ... measured at the final
> output stage of your station."  I haven't reviewed recent interpretations 
> of the FCC rules, but I would expect this is still their standard also
> is my basis for operations).  This is all fine and good at HF and lower 
> VHF, where minimal cable loss is somewhat trivial (except for those with 
> big towers far from the shack).  But consider the following scenarios 
> (approximations):
> Station 1
> Band 10GHz
> Power 10w (in shack)
> 10 db cable loss (~50' 1/2" heliax)
> Power at antenna 1w
> Station 2
> Band 10GHz
> Power 10w (preamp and/or transverter + power amp mounted at antenna)
> negligible cable loss (1' of 1/2" superflex)
> Power at antenna 10w
> ERP differential = 10db.  Power needed (in shack) for Station 1 to have
> same transmit signal as Station 2 = 100w.  So which station will win the 
> contest (all other things being equal)?
> So in the case of Station 2, power output is (effectively) measured at
> antenna.  The station setup for Station 2 is not uncommon and legal
> FCC and all contest rules, so this does indicate a situation where power 
> can be measured at the antenna.  If the desire of contest sponsors were
> make their rules more equitable (here we go again), power should be 
> specified at the antenna.
> If you desire to have a competitive station and remain beyond reproach
> the rules auditors, build to Station 2 standards, barring an explicit 
> clarification from the contest sponsors.
> Contests (expecially VHF+) will never be equitable, so just get on, do
> best, and have fun!
> At 06:53 PM 8/9/2006 -0700, Radiosporting Fan wrote:
> > > If I have a small amplifier  brick in my 902 MHz
> > > transverter putting out 20 watts PEP, and a
> > > measured 4 dB worth of relay, connector, and coax
> > > cable attenuation between it and the antenna, what
> > > class am I in and why.
> >
> >Hi Keith,
> >
> >For the record, my opinion and $0.99 gets you a "Big
> >Gulp" at the corner mini-market.  Here it is...
> >
> >Taking a close look at the ARRL rules for VHF
> >contests, you'll notice that they *never* reference
> >ERP.  On the other hand, they do reference the term
> >"Power Output" twice (Rules 1.15, 2.2.1).
> >Traditionally, this is the power measured at the final
> >output stage of your station.
> >
> >I do not work for the ARRL, adjudicate for the ARRL,
> >check logs for the ARRL.  I am happy, however, to
> >drink a Gig Gulp between contest CQ's. :)
> >
> >Regards,
> >Ev, W2EV
> >
> >
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> 73, Robert KR7O/YB2ARO, DM07ba/OI52ee  (ex.  N7STU)
> kr7o at vhfdx.com
> www.vhfdx.com (KR7O/YB2ARO homepages)
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