[UK-CONTEST] Antenna height on 70cms

[Peter Bowyer]

1) Not much point trying to move the discussion to your blog when you
disable comments;

2) An improvement of 36dB just by changing 25m of feeder is a result
that most level-headed observers would question;

3) You really are an arrogant tosser, aren't you?

Peter G4MJS

On 01/07/2009, Callum MØMCX <callum at mccormick.uk.com> wrote:
> >> you should easily become a multi millionaire overnight!
>
> Firstly, thanks for the encouragement, I am indeed, not short of a few bob.
> An amazing insight you have.
>
> Secondly, I conducted a "real-world" test - so either I make all this crap
> up or I'm completely mad.
>
> You decide.
>
>
> Callum McCormick
> http://www.m0mcx.co.uk/
> Yahoo Groups:
> - http://groups.yahoo.com/group/rsgb/
> - http://groups.yahoo.com/group/narrowboats/
> - http://groups.yahoo.com/group/nordhavndreamers/
> t: 07976 631881
> 65 Glendon Way, B93 8SY
>
>
> -----Original Message-----
> From: David Barber [mailto:david.barber at dbelectronics.co.uk]
> Sent: 01 July 2009 19:38
> To: 'Callum MØMCX'
> Subject: RE: [UK-CONTEST] Antenna height on 70cms
>
> Hi Callum
>
> That is an astonishing difference!
>
> For the figures quoted @ 432MHZ
>
> 25m WE103 = loss 1.88dB
>
> 30m Eco15 = loss 1.83dB
>
> So a theoretical feeder difference in your setup of 0.05dB.
>
> Now as an owner of a TS2000 I know the S-Meter on FM is a farce but for a
> moment lets take it as being correct and an S point = 6dB increase so your 6
> S point increase would indicate a signal level difference of 36dB at the
> radio.
>
> That really stretches the imagination and if correct you should easily
> become a multi millionaire overnight!
>
> :-)
>
> Regards
>
> David
> G8OQW
>
>
> -----Original Message-----
> From: uk-contest-bounces at contesting.com
> [mailto:uk-contest-bounces at contesting.com] On Behalf Of Callum MØMCX
> Sent: 01 July 2009 19:03
> To: uk-contest at contesting.com
> Subject: Re: [UK-CONTEST] Antenna height on 70cms
>
> Two facts to bear in mind.
>
> 1) Henry quoted me losses for Westflex at 70cms as 7.5db per 100 meters.
> Your losses may be a lot greater than advertised by James. I would be
> tempted to go for a 5m pole with a 10m coax run if I had to. The real world
> difference, assuming good take-off  at a good site between the two is hardly
> measurable.
>
> 2) Last month, I conducted a real-world test comparing of 25 meters of
> Westflex at 70cms -vs- 30 meters of Ecoflex 15. The difference between the
> two was staggering. A local station on the Westflex at S1 became S7 on the
> EcoFlex 15 using a TS2000 on FM. White dusty noise on the Westflex was fully
> quietening on the EcoFlex. My TX signal also shot up.
>
> In contrast, the differences at 144mhz was pretty negligible (an S point or
> so) which led me personally to believe that using Westflex for anything over
> 2m was a waste of time.
>
> EcoFlex 15 is *only* £5.80 per meter (!) currently with matching N-Types at
> £10 a throw. So an expensive hobby for some.
>
>
> Callum McCormick
> http://www.m0mcx.co.uk/
> Yahoo Groups:
> - http://groups.yahoo.com/group/rsgb/
> - http://groups.yahoo.com/group/narrowboats/
> - http://groups.yahoo.com/group/nordhavndreamers/
> t: 07976 631881
> 65 Glendon Way, B93 8SY
>
>
> -----Original Message-----
> From: uk-contest-bounces at contesting.com
> [mailto:uk-contest-bounces at contesting.com] On Behalf Of Ray James
> Sent: 01 July 2009 12:27
> To: UK-Contest; MM0BQI
> Subject: Re: [UK-CONTEST] Antenna height on 70cms
>
>
>
>
> --- On Wed, 1/7/09, MM0BQI <MM0BQI at blueyonder.co.uk> wrote:
>
> > I have two options for mounting my
> > 18ele 70cms antenna this weekend.  Site is on the
> > highest point of a rounded hill with reasonably clear take
> > off.
> > 1.  5m above ground with a 10m run of Wesflex
> > 2.  10m above ground with 20m of Westflex
> > Does the additional height cancel out the feeder losses or
> > is higher always better?
> > Thanks
> > Jim,  MM0BQI
>
> Hi Jim,
> You're only adding an additional approximate .375db of loss at the greater
> height so that's what I would run with to get the antenna that bit clearer
> of the ground. If it's only a "reasonably clear take off" then height will
> be more important for directions that are not optimal.
>
> 73 Ray GM4CXM
>
>
>
>
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-- 
Peter Bowyer
Email: peter at bowyer.org
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