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Title: RF through relay or switch? Post by: W7SOE on August 24, 2015, 12:35:04 PM Hi,
I am building the "Junker" amp. The design calls for switching in an extra 100pF at the input to the tank coil on 80m. This would normally be done with a two section band switch. Since my band switch is only single section I was going to have a micro switch on the band switch shaft that turned on a relay to switch in the extra capacitor. What about omitting the relay and just using the micro switch to the capacitor directly? Or perhaps a beefier switch of some type... Thanks Rich Title: Re: RF through relay or switch? Post by: DMOD on August 24, 2015, 12:53:28 PM Would the switch be able to handle high RF voltages and currents?
How much voltage isolation can the switch contacts tolerate? How much capacitance is across the switch contacts? This could de-tune your circuit. Phil - AC0OB Title: Re: RF through relay or switch? Post by: W7SOE on August 24, 2015, 01:25:25 PM Would the switch be able to handle high RF voltages and currents? How much voltage isolation can the switch contacts tolerate? How much capacitance is across the switch contacts? This could de-tune your circuit. Phil - AC0OB All good questions! I am thinking of taking apart a relay and just have a "cam" on the shaft push the contacts together. Rich |