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On Mon, 08 Mar 2004 18:14:24 GMT, Ken wrote:
I bought one of these last year and it worked OK for RF measurement. I am now for the first time trying to use it to measure the [digital] frequency at a chip pin. I set it for CMOS/TTL range. It reads 4.9 MHz open circuit and shorted out. Sometimes it reads zero. Nothing changes when I test the chip pin. I get the same result using an oscilloscope probe and solid copper leads. There is supposed to be a 5KHz signal at the pin. I can hear a tone roughly of that frequency (very high) when I put that pin on the input of an amplified speaker. Is my meter fried? Or am I doing something wrong? Ken KC2JDY Ken (to reply via email remove "zz" from address) I have an mfj frequency counter -- inexpensive. It works okay on strong signals; about 10 watts & up. Doesn't do worth a darn on QRP signals, 5 watts or less. I'm guessing your chip doesn't put out enough power for the frequency to be detected. You may need a more sensitive lab quality detector. Bob k5qwg |
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