Quote:
Originally Posted by Chris K
OK...not in any particular order...
1. How am I supposed to sweep the signal? The 2 frequencies, 22.05 and 24.75 are the peaks of the sweep in Figure 15 (and Fig 28 photo) and should be set in the marker generator correct?
2. Am I sweeping with a central frequency of 25mc a symmetrical sweep of 10mc? Is that what's required by the instructions "Sweeping 20-30mc" under the Sweep Gen Freq Mc column in the alignment table or am I reading that completely wrong?
3. Set bias -2V. Does that mean adjust the 250k pot for a reading of -2V at the R135-R136 test point as before?
4. Now for the biggie...shunt a 330 ohm resistor across the primaries of T-102, 103, 104 and 106. Does that mean connect 330 ohm resistors between the transformer tabs of the primary coils of all 4 of the transformers? How, solder them in? Please say no!  |
Here are my answers:
1. Yes this is the over coupled transformer link between the tuner and 1st IF stage. They advise you separately check and you are correct the peaks are 22.05MHz and 24.75MHz. Set the sweep generator to roughly 24MHz and set the sweep width to symetrical and widest seting.
2. No. What the instructions is saying is to roughly sweep to cover the bandwidth you are aligning. You want toe see the peaks and the srts of the resonse curve.
3. Yes that is it. Just be aware that you can overload the amplifier. Adjust the input RF sweep signal so that you get about 3 vDC at the detector.
4. I bought a bunch of 330ohm 1/4 w resistors and soldered small croc clips to either end. I then attached the croc clips to the terminals if the IF transformers. The reason for doing this is of course to remove the tuning of each IF stage so you can see the overcoupled transformer link performance.