<<< responses/questions embedded below >>> --- In [email protected], "nj902" <[EMAIL PROTECTED]> wrote: > > You can use a sweep generator and scope for swept alignment of > filters and duplexers. The manual for your sweeper should show the > setup & procedure. > > If you don't have the manual, try BAMA or other internet sites.
W6NCT: This sounds encouraging; unfortunately I do not have the manuals for the (Wavetek 1080) sweep generator; nor does BAMA as near as I can tell. I have started making enquiries around; but was hoping that someone might be able to tell me how to set it up in the near term. > > You will need an RF detector probe or preferably a detector such as > the HP 423A or 423B crystal detectors. These have a 50 ohm > interface to the device you are tuning and provide a rectified > output to drive the vertical deflection of your scope. W6NCT: My dad's equipment included a simple (full-wave) diode detector (i.e., RF in, DC out); would this be ok? > > The scope horizontal is driven by a ramp voltage from the sweeper. > Using the scope in X-Y display mode thereby provides a display of > device response versus frequency. W6NCT: I also have an oscilloscope. If it is being driven by the sweep generator, do you know how fast a scope it needs to be? The one I have with an X input is an older storage scope (20 MHz?). Might this be ok; or will I need a much faster one? As I recall, my dad used an old (5MHz?) Heathkit back when he used the sweep generator to align the Tx cavities on the UHF-TV transmitters, so I was guessing that a slower one might be ok. I tried connecting my oscilloscope (X and Y) to the sweep generator; but I can't get something to display on the screen that looks anything like a spectral waveform. Do you if or know how I need to connect the other IOs of the 1080 (RF out, demod in, and marker in)? > > Be aware that your display will be linear whereas a spectrum > analyzer + tracking generator display - or a network analyzer > display - will look like the duplexer manufacturer's spec sheet with > a logarithmic vertical axis. W6NCT: understood. > > You can also tune the duplexer using the generator in the IFR along > with a receiver that has a receive signal level indication - even > your repeater's receiver and a test meter showing the limiter. W6NCT: If I use the IFR to generate an FM signal at my Tx and Rx frequencies, and feed it into one side of the cavities; then how do I setup the output? Thank-you.
