UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Questions on 160/80 metre AM transmitters.

frsimen · 20th Dec 2022, 11:17 pm

The measured value of L3 is 195uH. It looks like the designer was trying to pull off having both a peak response at 80m and a rejection response at in the 160m region. LTSpice shows that the peak response is fairly easily achieved, the rejection frequency is rather high with a 22pF capacitor. The end result depends a lot on the stray capacitance.

Paula

20th Dec 2022, 11:17 pm	#33
frsimen Heptode Join Date: Jan 2011 Location: Croydon, London, UK. Posts: 773	Re: Quick question on the CODAR AT5, if anyone has one to hand. The measured value of L3 is 195uH. It looks like the designer was trying to pull off having both a peak response at 80m and a rejection response at in the 160m region. LTSpice shows that the peak response is fairly easily achieved, the rejection frequency is rather high with a 22pF capacitor. The end result depends a lot on the stray capacitance. Paula