Sweeper Source I

updated @12/23 2012

here is the final project , very ugly but very useful.  the project contain a ramp generator and a VCO. the ramp is  Ramp: linearity ramp generator .

sweep1
sweep 1

@update @ 2013/10/13,  new box, remove the ramp generator from the VCO, use ramp output from sweep: sweep signal source

the VCO derived from VCO: Ultra Negtive 100kHz-100Mhz, use the Secondary  ECL  low tank energy VCO, which suitable for  Varactors.

the total circuit is here:

Here is a reference layout for PCB.

 

@update 2013/10/6

 

1 year passed after i made this sweep signal generator, here is the problem:

 1. no suitable case, just everything solder together.

2. VCO cover only 455khz to 12Mhz.

3. ramp generator : X sweep range is from 0 to several voltage, then need  x10 probe to get perfect X sweep, actually the better way is use DC couple, -5V to +5V(-2.5 to 2.5 also good)

4. VCO sweep voltage from 0 to  about 10V, which is not enough, at least need sweep from 0.5V to around 15V.

5. VCO sweep width is not calibration.

6.  output level still not so flat, and output level is too low.   @2014/8/5

7.  no frequency counter interface, which needed to read out frequency.  @2014/8/5