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Interesting - Snow on roof

MadVeteran

Active Member
Sep 8, 2021
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OK, the snow is not the interesting thing but,
I put an inverted V dipole in my attic last summer expecting it to be fine in summer but, I wondered how it would be when the roof tiles were covered in Snow.
We now have on and off (still melting or blowing off for now) about a half inch to an inch of snow on the roofs.
I checked the SWR when there was definitely snow across the roof (1 inch or less) but had no increase in SWR at all.
- Is that normal?
- will SWR be affected once there is more snow/ice (will confirm soon BTW) ?

Cheers
 

sp5it

Master of puppets
Jul 9, 2009
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I have GP 1/4 for 40m with radials on the wooden roof. SWR is changing when wet or snow. From 1:1 even to 1:1.9
Mike
 

freecell

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Apr 6, 2005
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MadVeteran, sp5it:

the swr on the line is determined only by the matching conditions at the load.
when conditions at the load change, the standing wave ratio will change.

i doubt that anyone you work over the air has noticed any reduction in signal.
 
Last edited:

Captain Kilowatt

Professional Amateur
Staff member
Apr 6, 2005
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In Mike's ase, SP5IT, the snow is making direct contact with the antenna thus changing the stray capacitance which affects tuning. In the OP's case the snow is isolated from the antenna thus minimizing the acfect just as a radome does to an antenna.
 

MadVeteran

Active Member
Sep 8, 2021
101
193
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Thanks for all the input. I will let you know what the SWR is when there is four feet of snow up there.... Wont be long unfortunately.
 

MadVeteran

Active Member
Sep 8, 2021
101
193
43
A foot of wet snow on roof and, no change in SWR.
OK, this will cause replies,, I bought one of those ATS-100 Chinese auto antenna tuners (just because ok). After some confusion, I tuned every 11 meter channel and, they are all below 1.2 to 1. Not bad and looks cool with all the other black boxes.
My antenna wasnt bad, I just wanted the tuner. Some channels have been improved by the tuner.
Now,, I have antenna,,, tuner,,, 11 meter radios (and 10 meter radio), do you think its time i get my ham licence ?
 

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  • @ ButtFuzz:
    on the connector with the green wire, if you short that to a nearby black wire, the power supply will turn on. (for use as a bench supply or whatever)
  • @ ButtFuzz:
    And IIRC, the purple wire is -12VDC, but that is from memory and it does not serve.
  • @ ButtFuzz:
    So if you need, say, 7v, connect + to the Yellow wire and - to the Red wire.
  • @ ButtFuzz:
    or or you need 9v connect + to the yellow wire and - to the orange wire. note: not all PSU's have the orange wire nowadays, as many manufactures had the voltage regulation on the motherboard, and all the power supply gives is 12 vdc
  • @ BJ radionut:
    Thanks ROB will check it out!~!! got to clean the work bench a little make room for that big case :)