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8640Jr Bands

 

8640Jr Bands

Filed in homebrew on May.19, 2012

My 8640Jr has 5 total bands, covering 850 Khz – 31 Mhz.

I took some measurements with the Bandspread Control in the Maximum, Minimum and Midpoint of its range.

I started with the VFO output frequencies, as all of the other bands are arrived at by dividing these frequencies down.

With the Bandspread Capacitor set to Maximum, I had a range of 13.6 Mhz to 27.858 Mhz.


Lowest Frequency with Bandspread Cap at Max
 

 
Highest Frequency with Bandspread Cap at Max

 

Next, I set the Bandspread Capacitor at Minimum. It is clear that this affects the high end of the range much more than the low end.

 
Lowest Frequency with Bandspread Cap at Min
 
 
Highest Frequency with Bandspread Cap at Minimum

Finally, I set the Bandspread cap to the approximate center of its range, and made more measurements.

 
Lowest Frequency with Bandspread Cap at Mid

 

 
Highest Frequency with Bandspread Cap at Mid

 

Band 1     850.0000 Khz         1.9604  Mhz
Band 2     1.7008   Mhz         3.9209  Mhz
Band 3     3.4017   Mhz         7.8417  Mhz
Band 4     6.8033   Mhz         15.6835 Mhz
Band 5     13.6066  Mhz         31.3669 Mhz

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