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Old 8th May 2020, 11:01 pm   #57
trh01uk
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Default Re: Marconi C100 B28 vs. Eddystones

Quote:
Originally Posted by G6Tanuki View Post
Here we go: apologies for the crap phonecam resolution...

Remember that this analysis was done from the perspective of commercial point-to-point HF circuits, not ad-hoc ham-radio operation.

They don't mention the instability and wobbliness in the face of mains-voltage fluctuations, or the LO drift over several hours as the receiver warms-up after a cold-start. I guess 'commercial' applications had stable mains and involved receivers that were not subject to turning-on-and-offable thermal-cycling.
And what they do note is virtually all about the sensitivity of the receiver compared to its thermal noise floor. Which is odd - because virtually everyone knows these days that the noise on HF is such that thermal noise is simply an irrelevance. And with 2uV sensitivity I would have thought it would have been the same in 1936. Unless of course, the HF bands were genuinely much quieter back then?
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