For Sale: Vintage 12 page manual for making your own Pennywhistle 103 Originate Modem. With PC board templates etc.
Also includes what appears to be a companion device manual "Tone Decoder Phale Locked Loop Linear Integrated Circuits" paperwork as shown.
Additional higher resolutions photos are available.
Send your zip code and city for a shipping quote - should be between $2.99 and $3.99 if you are in the USA (March 2024)
