31-12-2021, 06:23 PM
(31-12-2021, 04:58 PM)VK2XAX Wrote: The 2m amp is taking shape, sweeping the filter shows it to have negligible insertion loss, see pic.
The spec analyser screen shows -47dB at 2F but looks to have about 2dB loss at 144 ?
Now the maths is that if 2dB is accurate as insertion loss in the passband means that at a 500W level into the filter, there is an output of power of around 316 watts. That could mean that 180-odd watts is going to be dissipated in the output filter !!!!! On SSB that might be an acceptable heating level but digital mode could mean burn-up.
How accurately have you measured the actual filter loss at 144 ?? What component types did you use ??
Doug
Doug VK4ADC @ QG62LG51
http://www.vk4adc.com
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http://www.vk4adc.com
This Forum is only going to be as interesting as the posts it contains.
If you have a comment or question, post it as it may trigger or answer the query in someone else's mind.