Wednesday, January 1, 2014

Maybe not such a good idea

Since the Club has started enforcing the use of the new membership cards,  many of us, myself included, have begun tucking our cards into our phone cases  so that we always have them handy...


while this is really convenient,  I've come to realize that it might not be such a good idea for phone usage..

Here's the way most of use talk on the phone when we have these kinds of 'phone wallet' cases:


Notice that the case is folded so that the body of the membership card is fully pressed against the back of the phone body.

For some time, I and my wife have been having some puzzling problems getting reception on our phones, despite having lots of bars (strong signal strength) ..Yesterday, we were trying to make some rather critical phone calls before year end , and I was having persistent transmission problems,  where I could hear the other party, but they could not hear me...     my wife was shouting into the phone to try to make herself heard to the technician on the other end, but it simply wasn't working....

Suddenly, I had a brain flash and plucked the card out of her case while she was in mid-call.... and the problem vanished...

There's a very good reason why this may have indeed been the solution...    What sparked my brain flash was that i suddenly remembered that these membership cards are  proximity cards and they actually have a big antenna coil inside them.  Notice that there is no battery anywhere inside this card.
These cards can work without a battery, because the antenna coil is designed to ABSORB power from surrounding radio waves to power the IC chip inside.  Depending on the radio frequencies involved, this coil has the potential to suck some or a lot of the power from our OUTGOING transmissions... thus, its very possible that this is why the folks on the other end of my calls could not hear me.

Whether its actually the coil sucking all the life out of your call or not...holding a big loop of copper wire against your cell phone is definitely not helping its radio transmitter's signal.