Home |
Search |
Today's Posts |
#2
|
|||
|
|||
You might consider putting varactors or switched capacitors across only
part of the inductor, i.e., a tap. The voltage will be lower and the required capacitance higher. You might also consider ways to change the inductance instead of the capacitance. Q, temperature stability, repeatability, and perhaps other factors will play a big role in determining which way is best, or acceptable. Roy Lewallen, W7EL Joel Kolstad wrote: I'm looking for suggestions on how one might go about changing the effective capacitance of a resonant circuit (it's part of a filter) in order to change the center frequency. The tricky part is that there's ~30dBm (10Vpp) RF running around, so with standard varactor diodes the RF becomes 'the bias' and the tuning is destroyed. I'm told that there are 'high voltage' varactor diodes out there; does anyone have a recommended source? This is at 500MHz and the nominal component values are ~3pF. If I could obtain a 2:1 tuning range, I'd be happy. I need perhaps 30 steps within that range (3-6pF), and (doing the calculations) each step changes the capacitance by little more than about 100fF to start with -- so I'm thinking that switching physical capacitors into and out of the circuit is out of the question here. Thoughts? Thanks in advance, ---Joel Kolstad |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
FA: MORE MULTIPLE LOTS of Various Electronic Components | Homebrew | |||
FA: MORE MULTIPLE LOTS of Various Electronic Components | Homebrew | |||
FA: MULTIPLE LOTS of Various Electronic Components | Homebrew | |||
FA: MULTIPLE LOTS of Various Electronic Components | Homebrew | |||
A Subtle Detail of Reflection Coefficients (but important to know) | Antenna |