Hi Jim,
If folk want to learn how to work the world on 160m top band DX from a
suburban block and cleverly work-around any perceived antenna height and
size restrictions then I recommend a careful read of Steve's VK5SFA very
informative website:
http://members.iinet.net.au/~sadler@netspace.net.au/
http://members.iinet.net.au/~sadler@netspace.net.au/tmla.html
A detailed eyebrow raising keynote presentation of this remarkable 160m/80m
TMLA was given at a technical symposium held at the annual WIA AGM last
weekend here in Adelaide. The session was augmented the following day with
live field demonstrations of its on-air performance and auto-tune features.
Steve's impressive 160m logbook of DX contacts racked up for the past year
of deploying this novel antenna is the envy of everybody here in VK land
including the sceptical diehard topband aficionados.
This is a prime example of the application of a bit of ingenuity for which
the amateur radio community are renowned for...to the contrary Jim, rather
than being doomed to failure as you incorrectly assert one can instead
experience rewarding nirvana!
The small footprint TMLA works because it's radiating useful power down at a
low angle to enable long-haul DX propagation path circuits. On Rx it also
exhibits an exemplary SNR in an urban/suburban environment in respect to
man-made noise rejection.
73
Leigh
VK5KLT
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Jim Thomson
Sent: Tuesday, 23 May 2017 9:31 PM
To: amps@contesting.com
Subject: [Amps] new amp race / antenna take-off angle
Date: Sun, 21 May 2017 19:14:09 +0930
From: "Leigh Turner" <invertech@frontierisp.net.au>
To: "'AMPS'" <amps@contesting.com>
Subject: Re: [Amps] new amp race / antenna take-off angle
Precisely correct Peter!
If the HF antenna lobe take-off angle is fortuitously optimal for enabling a
given DX hop path then QRP Tx power will wing it!
No amount of Tx power or Rx sensitivity / SNR will compensate if this sweet
spot in the prevailing ephemeral propagation path is missed...
73
Leigh
VK5KLT
## Both VK land + germany have a 10 meter... aka 33 foot height limit.
That now effectively just destroyed amateur radio. I dont know what take
off angle you are blathering on about Leigh.
At just 33 ft with your height restriction.... the only angle you are gonna
have is either straight up...or into the side of you neigbours home. 33 ft
will not clear anything, and is 100% ineffective.
Utility poles around na are typ 40 ft high, with the hv wire another 1.5 ft
above that. The typ home, with its well grounded chicken mesh, just beneath
the stucco. Toss in your 400 watt useless ..legal limit, and you are doomed
to failure.
Jim VE7RF
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Peter Voelpel
Sent: Sunday, 21 May 2017 6:26 PM
To: amps@contesting.com
Subject: Re: [Amps] new amp race
You can't compare antenna gain with transmit power.
Antenna gain is one part but more important is the different elevation
angles a directive antenna or the right antenna can supply.
You can't hear with power anyway.
And that applies to any band.
73
Peter, DJ7WW
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