Re: cripple cap

  • Posts: 651

Thanks ph2t, I hadn’t seen that thread either.

I just had a think about the capacitor and why it’s there. To put attenuation on a rxer isn’t a real clever idea unless you have problems with signal overloading. Even then it makes a lot more sense to attenuate the signal on the transmitter.

The capacitor on antennas is used for two reasons.
One is as a high pass filter to keep low frequencies out like power line noise. The other and more important reason is stray capacitance.

The antenna wire forms a capacitor with anything close to it. It’s not much, but it is more than enough to detune the tank circuit in the radio.
A capacitor in series makes sure than any stray capacitance is kept to a minimum.

So it is more likely that they had problems with de-tuning and added the mod as an improvement (sic). Does anybody know what the value of the capacitor is ?