Geoffrey Mackenzie-Kennedy wrote:
There is no doubt in my mind that the availability of "plug and play"
rigs and the growth of the ham population has increased interference
levels from what they were in 1946.
Hello Geoff!
I don't remember the bands in 1946, but I do remember 1956. The 40 meter
CW band was pretty well-populated in evenings. There were jammers from
Eastern Europe, etc. And the 'phone bands had hetrodynes from the AM
carriers.
Today there is much less activity on the CW bands (except during
contests, when they are packed), but the 'phone bands are usually
well-populated with SSB.
However, the main thing that has changed is that there are so many more
sources of man-made noise. In addition to power poles, motors and
thermostats, etc. -- which we still suffer from -- there are now
countless digital devices that emit RF. Add to this the ubiquitous cheap
switching power supplies on things like desk lamps, and you have a big
increase in noise level.
That's why -- and here I'm getting on topic -- a radio like the K3,
which has (or will have) a hardware blanker for some kinds of impulse
noise, an IF DSP blanker for others, a AGC function to reduce the effect
of pulse-type noises, a DSP noise reduction function, the ability to use
very narrow bandwidths with minimal ringing, etc. is appropriate for
today's conditions.
Really a far cry from the "ANL" switch on the AM/CW receivers of 1957!
--
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco
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