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PolyMorph SW Receiver
12-18-2018, 06:32 AM
Post: #1
PolyMorph SW Receiver
SW receiver from Hackaday.io
by Morph using poliakov mixer


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12-22-2018, 06:21 AM
Post: #2
RE: PolyMorph SW Receiver
I have somewhere 2N3094 but i cannot found it then i use
9016.
Transistor work properly but i cannot get any oscilation
after diode mixer.
Then i look into another similar design and i found
that VFO must be connected trough coupling capacitor
cca 100 pF which have ~220ohm on 7.1MHz
which should be 1/2 frequency of input /tuned signal
what is how polyakov mixer works.
Also diode ring works like a frequency doubler.
And what give us 14Mhz - 20 M band.
Author says that his antenna coil is 1.5uH what is not
possible if is dia 16mm/5 turns/ 5mm Len -> 520nH
my oscillator coil is 25 turns/16 mm dia / 26 mmm Len
and is 4.7uH.
In final i get some SW stations but are mixed.


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12-25-2018, 04:50 AM
Post: #3
RE: PolyMorph SW Receiver
So far i have this:


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01-04-2019, 04:15 AM
Post: #4
RE: PolyMorph SW Receiver
So far i don't have some results with this receiver
oscillator not work very well on 3V power supply and that is
probably why oscillator refuse to oscillate.
I tried version with tinySDR pnp configuration oscillator
but still i nothing.
If i configure circuit as regenerative receiver i get something
but with very low audio output.
It seems that i need first to test some regenerative receiver for
20 m first with coils i have.
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01-09-2019, 04:13 AM
Post: #5
RE: PolyMorph SW Receiver
I reconnect receiver part into normal regen receiver and seems that
oscillator work but simply cannot work with diode ring.
Probably created RF energy is not enough to mix into incoming signal from
antenna coil.
I will try to wind antenna coil over oscillator coil to see how much
injection i can get.


Another thing:
Amplifier JLH design work very well but because is A Class it
use to much current from fat A battery 2x1.5V
it is cca 95mA which is too much and dry bettery very fast
so is not good then i back to ordinar class AB with one preamp
transistor :
C1815
cR - 2k2
bR - 390k
bV - 0.76V
work excellent
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01-09-2019, 04:35 AM
Post: #6
RE: PolyMorph SW Receiver
Here is schematic:


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