Soap Box Oratory
In London’s Hyde Park there is a space called Speakers Corner where you will often find individuals expression their views on anything at all and doing so with or without an audience. Many speakers will deliver their message by standing on a box which gave birth to the term Soap Box Oratory One might fairly claim what I write here is an electronic equivalent.
The topic today is standards Now I am generally very much in favor of standards, as without them anarchy reigns . However some make little sense and one such is the FCC rule that spurious emissions on HF bands should be at least 43 dB below the power at the operating frequency . Recently I placed an order for one of the QRP-Labs Ultimate 3S multimode beacon kits (reviewed in the November issue of QST). It was reported that this FCC standard was not met on some bands. How concerned should I be ?
The low power community believe the challenge and enjoyment of Ham Radio is in inverse proportion to output power. OneWatt is a popular QRP level and figuring out -43 dB is an exercise we can all do in our heads as follows -30 dB is 1000th which gives us 1 milliwatt, another 10 dB down gets us down to 0.1 mW and the 3dB means half of that so we end up with 0.05 mW. Note the same -43 dBc applies to a 1 KW carrier and I would not even be concerned at the 50 mW especially if the spurious signal was out of band.
By now you should be familiar with the graph that shows natural noise levels increase dramatically at low frequencies. We find it tough at 160 meters but pioneering hams are exploring new bands at around 600 and 2000 meters with low power. I heard the first QRP contact between a VE and a VK has been achieved.
I greatly admire the designers of the Ultimate 3s WSPR QRP kit who are taking steps to correct the deficiency which amounted to around 1dB. Packing away my soap box for now, why not try speaking at speakers corner yourself.
73 and QRSS Ron W6WO