Speed correction of old radio shows
Old Time Radio programs come to us from a variety of sources - dubbed directly from original transcriptions or copies of tapes made many years ago.
One of the more frustrating aspects of listening to these shows is that often the speed of the program is incorrect. In some cases, the original transcription disc may have been recorded slightly off-speed, but more often tape copies of these shows done on cassette recorders or cheaper reel to reel decks can vary widely in quality.
Some collectors attempt to speed correct shows and may think that simply stretching out the running time to exactly 15 or 30 minutes will do the job. It's a bit more complicated than that.
Practically all of the AFRS transcriptions in my collection run over their allotted time - if you have a thirty minute show, it generally runs anywhere from 30:10 to 30:40. I think they were covering themselves if some of the local turntables were off-speed or to give a buffer if the local staff mis-timed something on their schedule.
Syndicated shows can be all over the place. In "Nonsense and Melody", those shows run run as long as 14:40, but many come in at just shy of 14 minutes. One early thirties syndicated show I have, "The Two Daffodils", runs anywhere from 10:40 to 11:45.
The series I dubbed called "Your Home Front Reporter" was recorded directly from the CBS line. It's fairly easy to set the correct speed of it since it's mostly music. It usually runs 24:40, but can go up to 24:50. The first program in the series runs 30:23. (So, that recording might be an audition that wasn't actually broadcast or perhaps it did run this long and they just faded the end on the network.)
The only shows that I've run into that have a fairly accurate time are NBC line recordings that include the system cue and the chimes - those should usually run 14:50/29:50 from the cue to the chimes. I've got one soap that has almost 15 seconds of silence from the end of the program until we hear the chimes, so if you don't have the chimes, the show running time can still vary quite a bit.
Your best bet, when you have the original transcription, is to start with the turntable running at proper speed and then to adjust it (if needed) based on the musical content of the show and/or comparing voices to known correct speed recordings of performers. My sense of pitch of pretty good, but I'll still use a guitar tuner to double-check musical content.
The speed of transcriptions in my collection is pretty consistent, but you'll run into one now and again that's a little too fast or too slow - I have a few examples of a government syndicated show called "Let's Go to Town" and one episode was recorded and released running slightly too slow, but others are "spot on". Proper speed is a big problem with OTR since most shows in circulation were dubbed from transcriptions to tape many years ago. Even professional releases come from these tapes that might not have been correctly dubbed - I've got a professionally released audio CD set of Jack Benny shows from one well-known OTR supplier that was digitally remastered, but a couple of the shows are dubbed waaaay too slow - poor Jack, Mary, Don and Dennis all sound like they're imitating Tallulah Bankhead with a bad cold.