[Elecraft] Ice on dipole under snow under ice

Mike Harris mike.harris at horizon.co.fk
Tue Dec 15 15:21:03 EST 2020


Snow and ice is transparent to HF. When I was in Antarctica we had an 
ice depth radar sounding programme. A DH Twin Otter would fly at 50 feet 
above the snow surface as indicated by the radar altimeter and beneath 
the wings were a couple of 70Mhz dipoles, TX and RX. The 70MHz TX pulses 
penetrated to the underlying rock. Take one height from the other, ice 
depth.

Fantastic flying that was.

It is mentioned in the ARRL Antenna Handbook that a closed loop array 
like a Sterba curtain could be could be fed with a low voltage DC or AC 
current to heat the wire to relieve it of accumulated snow and ice.

Regards,

Mike VP8NO

On 15/12/2020 14:45, David Haines wrote:
> Update:
> 
> With one-quarter of one leg of the dipole still under ice, I got a 
> reception report from PSKReporter on FT8 with 2 watts to Italy. That 
> shouldn't work, should it?  Maybe the ice doesn't matter?
> 
> KD5VXH recalled a discussion in QST on this very subject, where 400W AM 
> melted the ice on one leg of the dipole (fed by coax), but not the other.
> '
> You can follow the controversy in May and July 1960 letters in QST!
> 
> david
> KC1DNY


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