Re: #bitx40help BITX40 LSB Winlink #bitx40help
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To get 7MHz USB you need a BFO at (drumroll) 17 MHz. You have to point the ladder at -7Mhz in order to get the mirror image sideband. Am I right?
The magic is in the ladder/BFO combination, which shears off the carrier and unwanted sideband, while passing the wanted sideband. This is not touched in Allard's sketch. So... if you use, say, a 10MHz IF, then 3 MHz BFO will get you 7MHz LSB and a 4 MHz BFO will get you 14MHz USB. Of course you have to filter to make sure you have signal content where you want it to look.
Thanks Joe. Yup, Allard's sketch. That's what I got from Marco and Gordon's posts.Just to recite my new understanding, for those like me whose facility with superhet design strays just into and out of visibility -
On Mon, Mar 26, 2018 at 9:49 PM, Joe Puma <kd2nfc@...> wrote: