If you can find them one of the best sources for the 1750m band was Ken Cornell's "The Low & Medium Frequency Radio
Scrapbook". There were 4 editions, that I know of, from 1975 to 1982. They were a collection of circuits from everyone
that was experimenting at the time. Ken has long become a 'silent key' and so there hasn't been a new edition out in a
long time. Check around, you might find some available, they're well worth having.
73
Richard WB8KRN