Re: A little question...


Michael <michael.setaazul@...>
 

Standard-issue mortals just go into a store making huge profits and buy something
with a fancy label and glitzy front panel rom a suave salesperson. Been there, done it
- not infrequently with later regret. We few with Planet-Zog DNA like things to be
more challenging, unpredictable and failure-prone. Errare humanum est ...

TA7642, ZN414, MK484 or similar lend themselves to low-component constructs
which can deliver impressive results with a good ferrite or longwire aerial. The audio
quality of AM can be a revelation! These circuits are great fun to experiment with,
but have evident limitations.

Cheats - like me - cannibalise a cheapo superhet and add a FET frontend
with tuned RF amp and possibly with regeneration (aka Q-multiplier). The
cheapo can suddenly outclass itself. Selectivity will remain muddy, but audio
quality can outclass such piffling shortcomings - especially on local stations.
Standard-issue mortals can only live with a single tuning knob or button-press.
Non-standard-issue mortals have a perverse penchant for adjustable-knob multiplicity.

Ergo my interest in a low-noise tuned RF-amp feeding a proven receiver,
such as the SONY SRF-59. If I had a multi-acre aerial array, I just might
settle for that, however... Is Area 51 for sale, perhance?

Michael

----- Original Message ----- From: n3ikq

"Why hasn't anyone done even a breadboard for a simple inductively tuned AM radio?
Not a bit of digital hash, no PLL issues, etc."

There's something about the words "simple","breadboard", "ultralight" and "AM Radio" that are
challenging to put together. The natural evolution of radio has been from simple but low performance
to complicated but high performance. Superhet designs are the cream of the analog crop but are
pretty challenging to breadboard due to their parts count and complexity. Trying to breadboard one
that qualifies as an ultralight? Good luck! Crystal radios, trf radios, regen radios and
superheterodyne circuits are all over the internet. Home built SDRs are coming on strong. I've built
a Softrock Ensemble II SDR the size of a cigarette pack that will put any good receiver to the test
(but is very tied to a PC of some sort). Heat up the old iron and let us know how things are going.
If nothing else you will have a mad appreciation for the brilliant minds that came up with the "clas
sic" designs!

These are interesting links:

http://www.elliottelectronicsupply.com/kits/am-radio-on-a-chip.html

http://theradioboard.com/rb/viewtopic.php?t=3946

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