I would recommend you contact the station and speak with someone in master control or traffic in regards to which format they can take. If they can only take SD insertions (which is probably the case) Beta SP and Digibeta are THE standards in the industry, but they might be open to taking others (DVD for example). if Beta and DigiBeta is all they take then contact a local post house that has a FCP system and have them dub it to Beta or DigiBeta from your original files. If a local post house doesn’t have FCP, you could try making a DVD with the highest quality settings (use compressor 60 minute high quality widescreen) and they can make a dub from that to Beta or DigiBeta.
If by some miracle, the cable folks can take a HD insertion, and you don’t have a local post house that can do this, try Digital film tree at https://www.digitalfilmtree.com/. They are a FCP shop in LA and can make a pristine dub of your 720p edit (from a Hard Drive or DVD-Rom) to HD or SD format that your station will need.
BTW, in all likelihood when you sent over a DV formated spot, they brought that into their NLE and made a Beta Dub from the NLE. If they are on an Avid (likely) they had a heck of a time converting your DV file to something playable. So the fact that your DV dub looks poor when aired is probably in their attempt to deal with your DV files. DV is not a horrid format. 9 times out of 10 I make a MiniDV copy of a spot and have my post house make Beta dubs from that. As long as you ensure that you are happy with the qualtity of your Beta dub that your giving the stations, you should be fine.
T. Payton
OneCreative, Albuquerque, NM