[ARC5] BC-453 (or R-23) in AM reception

[Leslie Smith]

  Hi Wayne,
  Thank you for offering that info.  I'm going to stick with the
  original plan - rather than "unwind" the coils/ I.F transformers.
  i.e. I'm going to build a 3 transistor converter to go in front of the
  nav. set.
  Here, in Australia, the "beacons" still transmit weather reports, and
  it's useful to keep that capability in a set.

  My converter consists of one JFET (the mixer), and two other devices
  (PNP + JFET) as the local oscillator.  I think I can make the LO
  sufficiently stable that it won't drift more than 
  a few cycles (and so stay within the narrow band-width of the BC-453
  I.F. strip.  
  I built a home-brew 80m receiver using this basic design and it would
  stay zero-beat on the local slow morse station forever.
 

  The front-end converter is a good way to keep a '-453 running.
  I find an old/broken  transistor radio and "snaffle" the output
  transformer.  
  The 500-8 impedance match is close to ideal for matching the "command"
  phone output to a speaker.
  This gives modest but useful volume for a loud-speaker (provided I get
  a set with the lower "Z" output impedance).
  This is when I run the set from a 60v B+ supply.  
  I imagine a set running from 150v or 250v would have a good output.


  73 de Les Smith
  vk2bcu at operamail.com


On Mon, Jan 13, 2014, at 6:18, Robert  Eleazer wrote:
> Les:
> 
> I have some conversion instructions for modifying a BC-453 to get the AM
> broadcast band.  It involves removing turns from some coils.
> 
> Wayne    
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