[ARC5] BC Receiver Front End Converter

[Leslie Smith]

  Hi Phil,
  Thank you for your inquiry.  I built an 80m converter for an ATA
  "range" receiver.  
  I'm pleased with the way it works - I heard ZL (New Zealand) stations
  better than the local club station.
  My aerial was indoors - a wire draped around the picture rail.
.
  The circuit consists of a JFET mixer - very similar to the circuit
  often seen in the ARRL handbook.
  The RF signal goes to the gate, via a simple LC tank circuit.
  The oscillator is injected onto the "top" of the emtiter (oops, the
  source) resistor.
  The oscillator is crystal controlled, and I used a 3200kHz crystal
  followed by a buffer.
  This arrangement allowed me to use a commercial crystal, and moved 80m
  down to 300kHz.

  I extract the oscillator signal from a point of low distortion.
  I see this as important, because the maths infesr that a signal with
  low distortion results in less spurious responses from a mixer.
  I really do believe the maths is important.
  It's good practice to avoid generating spurs rather than filter them
  out.

  At the moment this rather simple circuit is drawn using a DOS program
  - ORCAD.
  ORCAD believes it owns the keyboard, so I've never found a screen
  capture circuit that will "grab" my design.
  It's such a simple circuit that I can easily re-draw it in TinyCAD,
  and I'll do that and send it over.

  I note that Mr. Stinson has already built and "published" a circuit
  based on the versatile NE602 (or maybe 612).
  If you have an interest I can send a copy of Mr. Stinson's circuit.  I
  haven't built that circuit, so I can't say anything about it.

  
  73 de Les Smith
  vk2bcu at operamail.com


On Sun, Apr 13, 2014, at 11:12, Phillip Carpenter wrote:
> Leslie,
> 
> I'm interested in building a converter for my BC-453 receiver. I'd be
> very interested in your circuit diagram for the 160/80/40/20 meter
> converter.
> 
> I also have the broadcast band receiver like you have but am working on
> the BC-453 receiver first.
> 
> I'd be most appreciative of any advice or if you can steer me in the
> direction of any good front end converter design, crystal controlled or
> otherwise.
> 
> Thank you in advance for your reply!
> 
> Respectfully,
> 
> Phillip (W4RTX)
> 
> Sent from my iPhone

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