On Sat, 2006-08-12 at 09:22 -0400, Bwana Bob wrote:
> Traditionally, that is true. Ham-band-only receivers were superior. Tuned
> circuits could be more selective because they tuned over a narrower range.
> VFO's, too, could be made more linear and stable, since usually they tuned
> only over a 0.5 MHz range. Designs are different today. Broadband front ends
> are the rule. There is no "preselector" tuning and VFO's are synthesized.
> There is no longer a big performance difference between general coverage and
> ham band equipment.
Though there might be. The broad front ends can be prone to 2nd order
intermod that the tuned front ends don't show.
>
> Now, do we need general coverage? When I got started in amateur radio in the
> mid-sixties, shortwave listening was a popular hobby among electronics
> enthusiasts, hams and would-be hams. Not so today. Shortwave broadcasting is
> being replaced by satellites and the internet. I can't think of any
> shortwave broadcaster that still maintains a North American service. You can
> still hear them, but they are beaming to other parts of the world, so
> signals are weaker here in the U.S.
Tuning the SW BC bands there are stations elbow to elbow and sometimes
overlapping, some overlap other services at the edges of the bands.
There seems to be a high interest in spreading propaganda to other
countries in all directions. I suspect those selling statistics about
ownership of SW receivers include hams though on 40 meters we'd prefer
there to be no broadcasters.
>
> There is still some interesting utility monitoring out there. I enjoy
> listening to USCG aircraft on HF and I also monitor some of the
> international air traffic control frequencies. That's about it, aside from a
> little SSB marine traffic. The military has been going to satellites and
> encrypted digital modes; likewise commercial operations.
But considering the possibility of hostile action on satellites, some
operations that went satellite have again added some HF backups.
>
> Nevertheless, when I go on vacation, the T-T Scout goes with me, but I also
> bring a portable AM/FM/SW receiver.
My ham rig with general coverage has such better selectivity and
frequency read out that its far better than most portable AM/FM/SW
receivers though its not so great on FM broadcast when close to a
station.
>
>
> 73,
>
> Bob WB2VUF
>
In this opinion, one speaks for oneself, not for all.
--
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer
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