Tim,
My single crystal was in the 1950's.
A crystal lattice could take in much of the 160 meter band and be pratical.
Thanks for your input.
73
Bruce
On Thu, 22 Dec 2016 15:49:12 -0500, Tim Shoppa wrote:
Bruce - It has long been rumored that the big EU multi-multis
have a crystal filter at their run frequency receivers. e.g. if they
are running on 7003.4, they have a crystal filter in front of their
receiver for 7003.4. have never observed that in my visits but maybe
in decades past, when receivers had less damage range, it would've made
sense. Also a good reason to put up a fight for ownership of YOUR run
frequency HI HI
I believe EMRFD has a schematic for a single-frequency receiver,
maybe not exactly like you described but similar in principle. Let me
see if I can dig it up.
Tim N3QE
On Thu, Dec 22, 2016 at 3:41 PM, K1FZ-Bruce wrote:
We know that limiting the noise pick up from more directions of an
antenna we can usually hear better. We also know if we limit the
noise from a receiver IF we can hear less noise, and better yet, if we
have a roofing filter earlier in the receiver we can eliminate even
more noise in relationship to the wanted signals.
What if we take it a step further, could we limit the band-with of the
antenna signal with a crystal lattice for 160 meters before the
receiver.
Years ago I played around with a single crystal at the input of an
old tube type receiver. It was remarkable what I could hear on 40
meters, on what seemed to be one frequency.
73
Bruce-k1fz
http://www.qsl.net/k1fz/beverage_antenna.html
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