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Old 8th Oct 2017, 1:25 pm   #9
Wendymott
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Join Date: Jun 2013
Location: Huddersfield, West Yorkshire, UK.
Posts: 813
Default Re: SSB Signal Generator

Another module completed...The "Up Converter" module requires 60m/V rms input to pin 8 to limit carrier "leak through"........ The SSD oscillator module AD9850 outputs a rather large 500 m/V after filtering and a Mar 4 amp.......... and this is not constant.... as the carrier reaches 30 Mhz it starts to drop off due to the low pass filter characteristic. The actual upper frequency required is 39 Mhz..and by then the output has dropped to about 50m/V rms.
As I want a relatively constant level I made a switched PIN attenuator, which is "channelized". The problem is that the impedance changes made it impossible to add the attenuator without an impedance match at the output, thus I used a MAR 6 on the output.
Maybe I am making a rod for my own back using the MC1496... but they are in stock.
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Wendy G8BZY
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