Page 1 of 1

Front end protection during thunderstorm?

Posted: Tue Jul 09, 2019 4:30 pm
by mikebrock
I have an RSP1A that's just came back from repair due to lightning surge front end damage. Can someone recommend a good front end protection device that can be bought easily here in the UK? Cheers...

Re: Front end protection during thunderstorm?

Posted: Tue Jul 09, 2019 6:43 pm
by glovisol
Hi Mike, Did you have an isolation transformer between the 50 Ohm input and the antenna? I doubt it. The best protection against surges and the best safeguard against common mode noise is a small low noise ferrite transformer you can make with a few cents worth of materials and 15 minutes of your time...come back if you need details.

glovisol

Re: Front end protection during thunderstorm?

Posted: Tue Jul 09, 2019 7:47 pm
by mikebrock
Interesting - please describe thank you...

Re: Front end protection during thunderstorm?

Posted: Tue Jul 09, 2019 8:39 pm
by glovisol
Low noise transformer data:
Toroid core: FT-37-43 (material type 43)
Ext. dia.: 0.375"
Internal dia.: 0.187"
Thickness: 0.125"
PRIMARY = SECONDARY: 5 turns enamel copper wire 0.5 mm dia. PRI & SEC MUST NOT OVERLAP

Just have a look at this thread. Read it all as many pictures on construction!!

https://www.sdrplay.com/community/viewt ... f=8&t=4109

You will learn the reasons why if you have the patience to read here, where I discovered the properties of low noise transformers:

https://www.sdrplay.com/community/viewt ... f=5&t=3352

Kind regards,

glovisol

Re: Front end protection during thunderstorm?

Posted: Tue Jul 09, 2019 9:56 pm
by mikebrock
Thank you - very interesting - I may very well experiment with this Low noise transformer to see what effect it has on my setup. I'm running a 135 foot doublet in a inverted V configuration with a balanced Z match. I use an antenna analyser to optimize for the best match on whatever hf frequency I want to listen to. lol

Re: Front end protection during thunderstorm?

Posted: Tue Jul 16, 2019 10:12 pm
by mikebrock
In the end I bought this off eBay 283521154413. Lots of different types to choose from of course if you search front end protection on google. Small price to pay for peace of mind. Never had an sdrplay to go like that before - but with the large wire antenna I'm using it just shows how easily it could happen.

Re: Front end protection during thunderstorm?

Posted: Fri Jul 19, 2019 8:56 pm
by SDRguy22
An isolation transformer will not protect against lightning damage. However it will help drain static voltage that you get during rain or snow conditions.

For nearby lightning protection you need surge protection devices that have a gas discharge tube and the device connected to a solid ground connection. Even with these damage to the radio receiver can still occur if the lightning strike is nearby. In the case of a direct hit nothing will protect an RSP. That is why it is wise to disconnect your radio equipment from any antennas if you suspect a lightning storm in your area.

Here are a couple of popular devices for lightning/surge protection. https://tinyurl.com/lightning-prot

Re: Front end protection during thunderstorm?

Posted: Tue Aug 06, 2019 1:09 am
by mike0agner
Let's be real here - all of these devices will mitigate, but not prevent, damage from a thunderstorm. You really need to shut down, disconnect (and preferably ground, away from the home) your antenna feedline(s), disconnect any power supplies from your PC

There's no way to actually prevent damage from a near strike or direct hit, all you can do is mitigate the effects. Even some commercial sites get seriously damaged when a near strike or direct hit takes place, and their bonding is far superior to what most hobby folks would have.

Mike