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General Category => General Discussion => Topic started by: pippopippoli on Mar 31, 2017, 03:33 pm

Title: What happens if I throw 100w in 75w antenna ?
Post by: pippopippoli on Mar 31, 2017, 03:33 pm
What happens if I throw 80 - 100w in 75w antenna ?
antenna : https://www.amazon.com/Authentic-Genuine-Nagoya-UT-72-Magnetic/dp/B016SIJX28 (https://www.amazon.com/Authentic-Genuine-Nagoya-UT-72-Magnetic/dp/B016SIJX28)
amplifier: https://it.aliexpress.com/item/400MHz-470MHz-80W-90W-UHF-Ham-Radio-Power-Amplifier-For-Interphone-Car-Radio/32418047167.html?spm=2114.010208.0.0.0Jf5OH (https://it.aliexpress.com/item/400MHz-470MHz-80W-90W-UHF-Ham-Radio-Power-Amplifier-For-Interphone-Car-Radio/32418047167.html?spm=2114.010208.0.0.0Jf5OH)
Title: Re: What happens if I throw 100w in 75w antenna ?
Post by: Robin2 on Mar 31, 2017, 04:37 pm
What has that question go to do with an Arduino?

...R
Title: Re: What happens if I throw 100w in 75w antenna ?
Post by: pippopippoli on Mar 31, 2017, 11:17 pm

(https://s29.postimg.org/h27htcjhz/image.png)
Title: Re: What happens if I throw 100w in 75w antenna ?
Post by: Robin2 on Apr 01, 2017, 09:58 am
(https://s29.postimg.org/h27htcjhz/image.png)
Don't you think, with your natural consideration for the people who pay for hosting this site, that you might assume it means "anything and everything related to Arduinos"?


...R
Title: Re: What happens if I throw 100w in 75w antenna ?
Post by: ballscrewbob on Apr 01, 2017, 01:35 pm
You sort of answered your own question.

So lets say you have a device that is RATED for a MAXIMUM of 3 volts and you EXCEED that by a good factor.

Chances are you'll let out the magic smoke and it will not work again.

RATINGS are not a "general guide" they are there for a reason.
If I rate a car for road use only and you go off road hill climbing or drive it off a cliff should I stand by any warranty ? NOPE !

Most bottom loaded antennas have coils inside. similar to (but not the same as) a transformer.
Transformers have ratings eg 120 Volts in and 12 volts out...
Those coils could be made anywhere (probably China) and you cannot usually see the gauge of wire used same as almost all Antennas.

Put 240 volts up its tiny little ass and tell me how long it will work without generating heat and melting off the cheap coating and shorting out to somewhere ?

There are some quite complex calculations for wire gauge and Antennas and the length of an antenna that also take into account the "standing wave ratio" (SWR) I suggest you read up on those sorts of things before attempting anything like what you want to do.

Radio ham forums may be a better place for this question but don't say you were not warned when they laugh.



Title: Re: What happens if I throw 100w in 75w antenna ?
Post by: SurfingDude on Apr 01, 2017, 10:24 pm
From the Wikipedia:
Microwaves are a form of electromagnetic radiation with wavelengths ranging from one meter to one millimeter; with frequencies between 300 MHz (100 cm) and 300 GHz (0.1 cm).

With that amplifier being in the 440 Mhz Ham band, at 100 watts of power, you will have the active element of a microwave oven. You want to check the safety concerns of your Ham License (you are licensed?) to see just how far you will have to be from it to avoid cooking yourself.
Title: Re: What happens if I throw 100w in 75w antenna ?
Post by: ballscrewbob on Apr 01, 2017, 10:29 pm
I don't think the OP is licenced in any form or he would have known a little more than what amounts to "Can I put a burner on my taxi / work radio"

I was a "licenced  ham" and an ex Pirate CB etc etc. in the UK but they don't have full reciprocal licence in Canada.
Title: Re: What happens if I throw 100w in 75w antenna ?
Post by: Robin2 on Apr 02, 2017, 11:00 am
to see just how far you will have to be from it to avoid cooking yourself.
Another candidate for a Darwin Award (http://www.darwinawards.com/)?

...R