EconOceanic
 

Bar Graph of Continuous Coverage

AM
Broadcast
160
meters
120
meters
80
meters
60
meters
49
meters
40
meters
31
meters
25
meters
21
meters
19
meters
17
meters
 
MhZ: 0.50-1.75 2.00-2.25 2.50-3.50 3.75-4.75 5.00-6.00 6.25-7.25 7.50-9.50 9.75-11.75 12.00-14.00 14.25-15.50 15.75-17.50 17.75-19.75 20
40-460@250uH  
  30-156@250uH  
    21-51@
250uH
 
  40-460 @ 40 uH  
    17-30@250  
    13-19@
250uH
 
  40-460 @ 20 uH  
    40-460 @ 15 uH  
    30-156 @ 40 uH  
    7.5-9.4@
250uH
 
    40-460 @ 10 uH  
    30-156 @ 20 uH  
    30-156 @ 15 uH  
    21-51 @ 40 uH  
    17-30 @ 40 uH  
    30-156 @ 10 uH  
    21-51 @ 20 uH  
    13-19@40uH  
    7.5-9.4
@40uH
 
    21-51 @ 15 uH  
    17-30 @ 20 uH  
    13-19 @ 20 uH  
    17-30 @ 15 uH  
    21-51 @ 10 uH  
    13-19 @ 15 uH  
    7.5-9.4@20uH  
    17-30 @ 10 uH  
    7.5-9.4@15uH  
    13-19 @ 10 uH  
    7.5-9.4 @ 10 uH  

About this Graph

Top row of indices indicates frequency range in meters.

Second row indicates frequencies in MHz. Divisions are calibrated to nearest 0.25 MHz (250 KHz).

Black bars indicate ranges of frequency coverage (without bandspread) for specified combinations of cap settings and tuning coil selections.

Grey regions indicate additional ranges of frequency coverage with max bandspread applied for specified capacitor and tuning coil.

Using this Graph

  1. Locate the frequency for which reception is desired.
  2. Read downward through this column to the intersection of either a black or grey region.
  3. Set radio controls to specified capacitor and tuning coil settings.
  4. Rotate variable capacitor control to locate desired broadcast. If broadcast cannot be heard, select alternate region and repeat procedure from Step 3.
  5. Adjust both antenna coil selector switch and bandspread switch for maximum loudness.
  6. Repeat procedure for additional coverage regions to obtain optimum reception, if desired.

Copyright 1997 Walter Heskes and Philip I. Nelson, all rights reserved. This radio construction project, including all descriptions, diagrams, photos, and the underlying electronic design, is published here for the noncommercial use of radio hobbyists. You may print and reproduce these project instructions for your personal use. Commercial use of this material is strictly forbidden.