Little and Large!

Continuing IT upgrades here at Copper Mountain HQ, I was amazed by two parcels that arrived together this morning.

One contained what turned out to be a huge 31-type split ferrite, which I ordered from Hamgoodies.  This was something I wanted to stick on the end of the heavy duty earth safety cable that is bonded to an RF earth stake outside the shack, and goes all the way back to the domestic AC input to the house.  This was prompted by a letter in a recent Practical Wireless, and this potential for noise hadn't (but should have) occurred to me before then.

A tiny 500GB SSD drive next to a huge type-31 ferrite!

Because our earth system is a Protective Multiple Earth (PME) type, then this safety earth connection can pick up mains noise, although I certainly haven't seen any sign of this causing problems with my endless overnight WSPR monitoring.

Needless to say, you should think about, understand and implement your RF and AC earth systems very well before sticking copper rods in the ground.  If you get it wrong, or do yourself something that you should by law get a professional to do, then if your house catches fire, your insurance may well not pay out.  This is very serious, and has been wrongly explained in both RadCom and Practical Wireless recently!  The following image depicts PME, and none of this article is advice or guidance:

PME mains connections.  Each RF ground rod you install must have a separate heavy duty AC earth back to the chocolate block (or equivalent connection) depicted above.  Seek professional guidance!

The other package was the complete opposite: it felt like an empty Amazon cardboard packet, but was supposed to contain a 500GB SDD drive.  Remarkably, there really was a drive in there!  I guess the age of the magnetic disk drive is largely over now, even though you could hardly say they were unreliable.