When adjusting the output power for the IF and rf signals of the signal generator?
typically not necessary. Alignment is generally done using the lowest signal level that gives a usable output. In effect, the receiver is the power meter.
One benefit might be comparing different sets for sensitivity.
_________________ -Mark "Voltage is fun to watch, but it's the CURRENT that does the work."
Joined: Jun Fri 19, 2009 6:34 pm Posts: 10257 Location: Long Island NY
Figure anywhere from $75 to $100 for a cable that isn't beat and intermittent, and anywhere from $200 to $600 for a sensor that still works. Don't even consider a sensor that hasn't been tested by somebody who knows what they are doing, or doesn't come with a right-of-return. RF power meter sensors are easily damaged by feeding too much power into them and once that happens, repairs are not cost effective. You don't want to end up with somebody else's mistake! Damaged sensors may still appear to work when connected to a meter, but sensitivity and accuracy won't be where they should be.
As for use in FM receiver alignments, it seems rather pointless. A power meter has to operate on a known impedance (e.g. 50 ohms) to give useful readings; this impedance seldom occurs in FM radios of the entertainment variety. Also, there is usually a certain minimum level such as -50 dBm below which the sensor simply doesn't read, and that level may still be too high for direct connection to an RF or IF stage in a receiver. One can always measure a higher level and then pad it down, but it's not clear what is being accomplished.
_________________ "Hell, there are no rules here--we're trying to accomplish something!"
