[BC] AM Stereo

[Bob Tarsio]

Rich: I have forgotten the year, I believe 1969, I went to the AES Convention at the old Hilton Hotel in downtown LA. In the Sansui demo room they had two of their super tuners one was tuned to KHJ -930 who were also running the Kahn DSB system with a STA from the FCC. In the other bedroom was XETRA 690 from Roserita beach, Mexico with Kahn and the McLendon easy listening format. Both stations had excellent AM stereo with differing formats at the time. On the same trip I was carrying two Sony portable radios that were picked for their AM performance. I was staying with friends in Pasadena and we put the two radios on the coffee table in their living room and tuned to both stations. Good stereo and quality. On XTRA you would ocassionally get some noise on the right channel from KMPC's lower sideband.
Sure wish I had bought one of those tuners. Most of the Kahn stations had one or two of those receiver from Sansui. The sound good on AM mono stations.
Dave Hultsman
Dave:
Rich probably remembers this because we worked for Leonard in the early 80s. Kahn made a really nice demodulator that accepted the 10 MHz IF from a Potomac Instruments AM receiver. When coupled with that front end the Kahn decoder which had a wide band mode that went out to at least 15 KHz also had switchable 10 KHz notch whistle filters. This was before the NRSC curve adoption and when that decoder was used with the whistle filters in really worked great at night. We did a demo in a hospitality suite at at the old NRBA radio show with this setup and I remember a guy comes into the suite and stands in front of the setup and listens for a couple of minutes. He turns to us and says "yeah this a great demo of a local FM station but how about switching it to AM?" To which we said this IS AM! It was that good.
 
Regards,
 
Bob