During the recent webinar including a presentation by Walt Cooney about cv's, there was some discussion about what sorts of spectra might be worth having before/during/after T CrB erupts. Paula Szkody noted in the chat that papers by Bob Williams were a place to start. I recalled those papers from the 1990s when Williams was at CTIO and led a group getting spectra of numerous events. Looking at some of them again, a few struck me as perhaps useful for folks with spectrographs wanting to have some idea of what to expect without getting too much into the modelling. These are really nice since in many cases the example spectra include both the violet and the far-red. Looks as though there is plenty of action in the middle range between 4000A and H-alpha, however.
Start with:
https://ui.adsabs.harvard.edu/abs/1992AJ....104..725W/abstract
The Formation of Novae Spectra
Two substantial papers from the Tololo nova survey are here:
https://ui.adsabs.harvard.edu/abs/1991ApJ...376..721W/abstract
The Evolution and Classification of Postoutburst Novae Spectra
https://articles.adsabs.harvard.edu/abs/1994ApJS...90..297W/abstract
The Tololo Nova Survey: Spectra of Recent Novae
In the second paper, note especially the example spectra with M-giant secondary stars, i.e. presumably like T CrB. Much variation in the spectra, so (as Paula also noted) crazy stuff happens in the spectra once the initial fireball becomes transparent.
In the mid-20th Century, Dean McLaughlin was the pre-eminent observer of novae and their spectra (also a first-rank visual variable-star observer). Bear in mind that at the time he did not have the theoretical tools we have now, and the notion that _all_ cv's are binaries was still in the future. Nevertheless the descriptions of the spectrum details are accurate. One of his more brief papers describes the T CrB outburst spectrum from the two events available to him:
https://ui.adsabs.harvard.edu/abs/1946PASP...58..159M/abstract
The Spectrum of T Coronae Borealis in 1946 and 1866
\Brian