[600MRG] Antenna Food and alternate antenna thoughts...

[Dave Riley]

> When I oversaw the rework of the WBZ transmitter site in 1979 I 
> perceived a LOT of Westinghouse history and spent a year with hands on 
> experience as well as overseeing the building trades for a complete 
> makeover which had been exaserbatedby a recent violent storm that 
> rendered the entire site almost useless, however we stayed on that 
> air... The project included an immediate emergency overhaul of the on 
> site diesel generator, a complete building overhaul, rework and repair 
> of the two 190 degree high towers, new 3" transmission lines, new line 
> terminating units and a clean up of the salt marsh radial field... 
> This was an up close and personal look at watching a lemon becoming 
> lemonade...
> After we ran a full proof of performance on the new array along with a 
> brand new building electrical feed we returned to 'remote control' 
> operation and it has remained that way for 38 years now...
>
> Lesson learned: Taller than one half wave towers work about the best 
> and then on a salt water platform....
>
> This means that a short vertical antenna becomes less that normal 
> efficiency if we try to make say a 1' vertical and then learn the 
> reasons for looses which render the short vertical almost useless...
>
> Here is what I see as an improvement to short vertical antennas as 
> well as for loop antennas at these frequencies:
>
> If we really want to run a 'Tesla' coil as an antenna then we must 
> counterpoise it against a real ground like salt water, a large steel 
> ship, or take the looses that are sure... Then make our 'wet noodle' 
> in the same fashion as Tesla himself did with his coil, take it from 
> there...
>
> If I want to make my vertical loop radiator more efficient then I have 
> to use something like 4" copper strap all around for the entire loop 
> instead of #16 wire then I can expect to run something like 8 watts in 
> for a 5 watt eirp... Right now I'm only getting about 10% efficiency 
> and certainly do notice the poor power factor... It's that simple but 
> I do not have 4 inch copper strap to go around and feel that the pay 
> back would straight line to about 30 years and I'm on my last legs now 
> so why don't I just enjoy a very lossy antenna...
>
> Anyway, its food for thought...  TNX for sharing all this old time ham 
> radio fun...  DaveR AA1A