Tom, Point taken. I just pulled that figure out of the air, for illustration purposes, with no intention of presenting it as an actual measured value. I agree that it was an unrealistic example. Mea Culpa!
Perhaps a better example would have been a typical wirewound power resistor, which might measure exactly 50 ohms for DC resistance, but would be highly inductive and almost useless as an RF dummy load. There are such devices as "non-inductive" power resistors, but that doesn't necessarily mean that they are okay at RF. I have tested a few "no name" dummy loads that were close to 50 ohms DC resistance, but nearly 65 ohms impedance at VHF. The Bird and Microlab dummy loads in my collection are extremely close to 50 ohms impedance. I completely agree that a name-brand load that measures close to 50 ohms DC resistance will likely be close to 50 ohms impedance. 73, Eric Lemmon WB6FLY Tom Manning wrote: > > Eric > I fully agree with your assessment of the impedance problem except the dummy > load statement. I have never seen a good quality dummy load (Bird or other > similar quality) measure anything like 50+-j86 ohms... Generally if a good > Fluke digital meter reads 50 Ohms at DC the frequency response will be very > close to that up to about the upper usable freq level... Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
