[HBR] what is the BEST receiver

[N2EY at aol.com]

In a message dated 7/28/05 4:52:42 PM Eastern Daylight Time, roomberg at ptd.net 
writes:


> What is the best receiver for listening to HF SSB and morse code (CW) ?
> Is direct conversion better than superhet?
> Is tube better than transistor?
> Is discrete component beter than IC packages that have complete mixers 
> and PLL all packed up real neat on a single cheap?
> Is SMD better or worse for building receivers?
> 
> What I really want to know is what is the absolute   best way to build a 
> SWL receiver for 7 mhz to do ham radio morse code at  7.000 to 7.050 mhz .
> 
> A brand new SWL radio can cost over $500 .
> I don't really want DC to daylight.... all modes... I just want to know 
> about morse code reception.
> What is the best way to listen to morsecode on 7.040mhz?
> I have had Kenwoods, Icoms, HEATH, MFJ and  rockmites, knightsmites and 
> small wonder labs DSW40 rigs
> so what I want to know is what is supposed to be the best receiver you 
> can use for 7 mhz and if you build it, what parts...SMD, IC...or 
> tubes... should be best for pulling weak signals out of the air.
> 

A lot of questions - but before they can be answered, you need to
define what is meant by "best".

In the area of performance measures, there's sensitivity, selectivity,
dynamic range, drift, dial accuracy, tuning rate, spurious responses
and AGC characteristics, to name just a few.

Then there's cost, size, power consumption, maintainability, ease of
repair and maintenance, and other characteristics.

Every design and technology is a compromise - a trade-off. Maximizing
some things results in reductions in others. What's "best" depends on
what tradeoffs *you* prefer.

For example, it is possible to build very sensitive receivers - 0.1 microvolt 
or better for 10 dB signal-to-noise ratio. But such sensitivity is usually 
attained at the cost of dynamic range. And on 7 MHz, with most antennas, that 
much sensitivity is wasted
because the background noise picked up by the antenna is much greater than 
0.1
microvolt.  

One way to answer the questions is to look at the receivers you've used, and 
list
what was wrong with them - where they fell short of the ideal.

73 de Jim, N2EY