By Sindre Torp, LA6OP, Norway

model 587 audio band pass filter

The Drake Model 587 is an audio pass band filter. It should be inserted between the microphone (crystal Hi-Z) and the transmitter. Audio in the range 415-3100Hz passes through, but audio with frequencies outside this range is attenuated. The result was better sideband supression on SSB. Price when new in 1955 was $12.95.

Photo: Joe Veras, K9OCO.

Thanks to Joe Veras/ARRL for permission to use the photo. This and more than 800 images is displayed in 50 Years of Amateur Radio Innovation Supplementary CD by Joe Veras, K9OCO, available from www.arrl.org

(c) 1998-2012 SINDRE TORP, LA6OP, Norway. - DRAKE is a registered trade mark of R.L. DRAKE COMPANY
No copy of text or image without a written authorization.  E-mail: sindtorp@online.no
Last updated: April 9, 2012