On Fri, 3 Aug 2012, Brenda Ann wrote:

"Michael Black" wrote in message
ample.net...

Do you remember the giant sunspots during the 1960's you could see
with the naked eye? Solar flux over 200. I used to pick up WWV on 25
MHz on my cheap walkie-talkies. New Zealand used to blast in around
midnight local time just below 18 MHz. Good times.

I'm surprised you could hear 25MHz WWV on a cheap walkie talkie. Surely
band conditions opened up that you'd get all the CBers first, so they'd
wipe out WWV. The superregenerative receivers were wide band, but the
CBers were a lot more plentiful.


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In the 60's, there were relatively few CB'ers, and the ones that were around
were legal 3 watt output. The big CB boom didn't happen until around 1971 or
72. WWV would have been what? About 50KW? At any rate, a lot more powerful
than a 3W CB.


I didn't think there was that big a difference between "the sixties" and
1971 in regards to CB. It was a small number of channels, and almost from
the start some were trying to DX. But even without those attempts, people
realized early on that it was the wrong place in the spectrum, because
with the skip in, you did get everyone else. I don't know what it was
like when the boom hit a few years later, but with a crummy Hallicrafters
S-120A receiver that had little selectivity and little sensitivity in
1971, when conditions were good, it wsa a solid whine across the CB band.
I'm pretty sure that would have been the case even a few years earlier.

The issue isn't so much density, but that skip might come in from multiple
places, and each place was using those channels, so added up, it made the
whine.

Remember a superregen has virtually no selectivity, which is why he could
hear WWV at 25MHz when CB started just below 27MHz. But that also meant no
real selectivity, just a multitude of stations coming in when conditions
were good.

Michael