An Aerial Problem?

[Shutpa]

Bought a digital radio a month ago and because it worked so well without the aerial extended, I never bothered even touching it. Yesterday, my son decided to pull up the aerial and noticed that when the radio was plugged into the mains, he got a 'tingle' from the aerial that he did not get when used on batteries only. I tried it - and he is right.
Apart from a minute electrical leakage, is there something else that could be the cause of the 'tingle'?

 

[ericmark]

For a radio receiver there should be no power to aerial. For a transmitter then there will be power and RF burns are nasty and take a long time to heal.

Having said that many years ago I bought a TV from Argos and noted I got a slight shock from the aerial and measuring with my Avo Mk8 noted the voltage measured was very different to earth according to scale selected showing it had a very high internal resistance. On contacting manufactures we were told that it was due to the switch mode power supply and the leakage was within acceptable limits and would cause no harm.

I pointed out although the shock may not kill it could be enough to cause anyone working on the aerial to let go and it was the contact with the ground that was likely to cause problems after falling off a ladder and I returned the set.

It is considered that 30ma is not likely to do any permanent damage. However 10ma Earth leakage trips are used and these should trip between 3.3ma and 10ma so the maximum any item could leak without tripping an earth leakage would be 3.3ma. With 1mohm considered as minimum insulation then one should fail any item leaking more than 0.23ma this is a very small amount of current and unlikely one would detect such a small amount of current. With very dry hands and light touch one might just feel it.

So I would play safe and return the item as faulty. The capacitors used to remove the spikes which can cause interference to the radio may just about give enough current to feel but far more likely some thing wrong with radio and so better to play safe.

Unless of course it does transmit? With my transceivers one can at wrong point of aerial get nasty burn which take ages to heal. I have transmitted packet radio and you can get digital transmitters but in the main one needs an amateur licence for this type of radio so one should not need to ask the question.

 

[Shutpa]

Thanks for your reply. I wont pretend that I understand any of the technical stuff but I do understand the advice to return the radio and that is what I will do.