antenna issue

[N2DTS]

I have two antenna's, an 80 and 40 meter fan dipole and the old 40 meter only dipole.
Both are the same 45 feet up and fed with coax.
The 40 meter one has slowly gone up to 3-1 swr for some reason, maybe it streched, the 80-40 meter antenna I just made and it was 1.2 to 1 at 7290 and both antenna's were somewhat broad banded.

When it is very wet or ice/snow covered, the antenna that normally has the 1.2 swr goes to 3-1, and the one that is 3-1 goes to 1.2-1.
This is very handy, but why does it happen?
 

[KA2DZT]

I have two antenna's, an 80 and 40 meter fan dipole and the old 40 meter only dipole.
Both are the same 45 feet up and fed with coax.
The 40 meter one has slowly gone up to 3-1 swr for some reason, maybe it streched, the 80-40 meter antenna I just made and it was 1.2 to 1 at 7290 and both antenna's were somewhat broad banded.

When it is very wet or ice/snow covered, the antenna that normally has the 1.2 swr goes to 3-1, and the one that is 3-1 goes to 1.2-1.
This is very handy, but why does it happen?
 

Is this a trick question?

Both antennas are being affected the same way.  It's just the affect is bringing one antenna back into resonance and the other out of resonance by the same amount.

I would fix the one that is out of resonance on clear days and disregard the affects of the snow.  Or, leave it as is and you'll have one good antenna for snow storms.

Fred

[N2DTS]

I was going to redo the 3-1 one till I found out it works great as a snow/ice/rain antenna.
Is it a ground thing, the wet ground changes the swr?

[KA2DZT]

I was going to redo the 3-1 one till I found out it works great as a snow/ice/rain antenna.
Is it a ground thing, the wet ground changes the swr?

Could be, the same thing happens to my antennas in the rain and/or snow.  I think a heavy layer of snow and ice would make the antenna resonant lower in frequency.  Reason, the antenna element/wire becomes much thicker.  Thicker elements are shorter in length than a thinner element would be for a given frequency.

[W6ZKH]

I just wish I had some rain here to change mine.....
John W6ZKH

[W2VW]

My non-resonant antenna tunes exactly the same no matter what the weather.

Maybe resin ants don't like water.

[N8ETQ]

    Wonder if ICE is a better insulator than water..

/dan

[KB2WIG]

D,


Yeah, ice is a better insulator...  around 0 F its about 86 Meg Ohms per cm and its about 24 Meg Ohms per cm at 70F. Of course, adding a bit of salt changes things........   And then there is the Debye–Falkenhagen effect.


klc

[KL7OF]

D,

    And then there is the Debye–Falkenhagen effect.


klc

I dated her in the 60's

[W3RSW]

Me too.

I heard from some of the boys, mostly from the finest private schools, that she was widely known up and down the east coast.

 

Um, back to antennae, I use a tuner in good wx and bad.