[Lowfer] 472-479 kHz

[pbunn]

My point is that power is cheap and efficient antennas are not and that it is cheaper to build a power amp than to greatly improve the antenna efficiency. For equal results - it is cheaper to go with power vs antenna efficiency.  

A ten foot antenna would be a very bad idea.


Pat

-----Original Message-----
From: lowfer-bounces at mailman.qth.net [mailto:lowfer-bounces at mailman.qth.net] On Behalf Of Douglas D. Williams
Sent: Tuesday, September 25, 2012 9:53 AM
To: Discussion of the Lowfer (US, European, &amp, UK) and MedFer bands
Subject: Re: [Lowfer] 472-479 kHz

Hi Pat. I don't believe anyone is suggesting that any amateur would seriously consider trying to erect a physical 1/4 wave vertical at 600 meters. ;-)

What is important, IMO, would be putting up the best antenna you could reasonably afford and have space for, say for instance a 50 to 100 foot high "T" antenna strung between two trees or other support structures, or some sort of base insulated tower or pole as the radiator with a "capacity hat" (two wires would do) extending out in opposite directions. Such an antenna need not be very expensive, and would certainly make more sense to me than trying to put a 600 meter signal on the air with a 10 foot long antenna.

As far as I know, the FCC has not made any rulings yet on the new 600 meter band.

I would think you would be correct as far as the receive antenna. A tuned loop would probably be the best bet for that.

73,
Doug

On Tue, Sep 25, 2012 at 8:47 AM, pbunn <pbunn at matrixei.com> wrote:

> Power at 600 meters is cheap and very easy. Efficient antennas are 
> large and very expensive (very expensive - and a 1/4 wave vertical is 
> nearly 500 feet high. Would cost well over a  million dollars or so 
> counting the radial system. A 1000 watt amp can be built for $500.  
> There is no such thing as an efficient short antenna.
>
> I have not heard the power limit for the US band but WARC allowed 5 
> watts EIRP. Other counties still using the band would be limited to 1 watt.
>
> Has the 1 watt ruling been made by the FCC?
>
> I would not think many would  receive with the transmit antenna 
> although it would probably be more efficient  than a probe. LF is a different game.
> I have an excellent receiving setup with a 6' whip antenna. S/N ratio 
> is the end game.
>
> Pat
> N4LTA
> WG2XCT
>
>
>
> -----Original Message-----
> From: lowfer-bounces at mailman.qth.net [mailto:
> lowfer-bounces at mailman.qth.net] On Behalf Of Douglas D. Williams
> Sent: Tuesday, September 25, 2012 5:44 AM
> To: Discussion of the Lowfer (US, European, &amp, UK) and MedFer bands
> Subject: Re: [Lowfer] 472-479 kHz
>
> On Mon, Sep 24, 2012 at 5:45 PM, craig wasson <craig at wasson.com> wrote:
>
> >
> > I work 60M mobile - and there is some incentive to have a bad 
> > antenna
> > - since power is rated in ERP.  The worse the antenna - the more 
> > power you can run.
>
>
>
> Yes, but the only power that counts is what is being radiated by the 
> antenna as RF. So, what's the point of pumping 100 watts into an 
> inefficient antenna when the same amount of RF could be transmitted by 
> pumping 10 watts into a more efficient antenna? Not to mention the 
> fact that the less efficient antenna is also likely to be much worse 
> at receiving.
>
>
>
> >
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