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Old September 22nd 08, 08:13 PM posted to rec.radio.amateur.homebrew
Bob[_18_] Bob[_18_] is offline
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First recorded activity by RadioBanter: Sep 2008
Posts: 40
Default CW is a hobby (off topic BWTH)

AJ Lake wrote:

If you only tested your tube receiver against *some* receivers then
your claim about outperforming *all* SS receivers would be invalid.


I've tried them against the *very* *best* receivers available today, and
they win in /every/ respect. They're actually hybrid receivers - I happily
use semiconductors where they're more appropriate (like in synchronous
demodulators, audio filters, audio amplifiers, local oscillators and so
on), but the really crucial parts - the RF amplifier, first mixer, IF
amplifiers and product detectors all use bottles.

There's one crucial parameter that's carefully omitted by most
manufacturers, which is the behaviour of their receivers in the presence of
strong adjacent frequency interference. The intermodulation, de-sensing
and other disasters inherent with semiconductor designs mean that I'll get
better results /every/ time.

I've designed /commercial/ solid-state receivers, and there's just *no*
*way* to get results as good as can still be obtained from valves in
crucial parts of them!

I haven't seen /any/ digital processor
that assists me in actually picking signals out of QRM.


*You* not having seen any doesn't mean there aren't any.


I've tried most of the stuff on the market, and /none/ of it can really
enhance a truly good receiver. They /might/ compensate for the obvious
shortcomings of some of the more average receivers!

pseudo-selectivity given by digital filters with all their nasty
artifacts)


Selectivity is not usually my problem. With close neighbors and a low
wire antenna, it's man made noise that is my problem. Digital does
well with this.


I'm in the happy situation that I don't suffer from too much of that,
despite living in a city (London). There are some really effective
noise-cancelling methods that have been published over the years - one
approach I used successfully in my old QTH was the counterpoise method that
was published years ago in RADCOM.

I'm happy for you if you're happy with your digital Rice Box


Yes we have hams here that are also 'Rice Box' prejudiced.


I'm not prejudiced at all - as soon as Far East Asia produces something even
half as good as I can build, I'll save time and effort and buy them! In
the interim, I'll continue with what I consider to be the real essence of
our hobby, and build the gear myself!

Prejudice for everything produced in Asia is silly these days.


Not at all - they /still/ can't make a good mobile phone! 8-)

Bob