duncan@zygot.ati.com (James R. Duncan) (01/20/91)
In article <1991Jan19.012221.2484@Solbourne.COM> kucharsk@Solbourne.COM (William Kucharski) writes: >He's recently inherited a Heathkit shortwave radio which works well for him but >it's got the old "slide-rule" type tuning. He wants to know if there's any >way you can build any type of quasi-accurate digital frequency display for >the tuner, based on the frequency being received. > I have an old Hallicrafters S-76 which I converted to 100% solid state (including synchronous detection!). What I did on this fun little toy was add a simple FET buffer stage to the first LO and then plug in a counter. Being more of an RF person than a digital person, I ran out of gas before creating some sort of method to subtract the 1,650 khz IF frequency from the counter reading. Nevertheless, this counter, which I unplug and use for other things when necessary, works fine as a dial frequency indicator (except for the constant +1650 kHz readout!). -- w ["] | WA6MBV |___|_____..duncan@zygot.ati.com | Jim Duncan H | (408)297-5977 \_____I_____/ 37 3 10N/121 59 10W ---------------
dmturne@PacBell.COM (Dave Turner) (01/23/91)
In article <1991Jan19.012221.2484@Solbourne.COM> kucharsk@Solbourne.COM (William Kucharski) writes: >He's recently inherited a Heathkit shortwave radio which works well for him but >it's got the old "slide-rule" type tuning. He wants to know if there's any >way you can build any type of quasi-accurate digital frequency display for >the tuner, based on the frequency being received. A quick scan of some old magazines shows three references to building a digital dial. All are old. The last used the fewest ICs and had an easy way to program the offset between the LO and IF frequencies. It said that it should be used only on single conversion radios but I imagine that you could program it for the combined offset if you knew both IF and LO frequencies. Build Your Own Digital Dial 73 magazine July, 1978 p 66 Digital Frequency Readout for Shortwave Receivers Popular Electronics February, 1977 p 49 Digital Frequency Display Radio-Electronics Special Projects Vol. 1 No. 1 Winter, 1980 p 65 While this last is 10 years old you might try writing to the address given in the article: Technico Services P.O. Box 20HC Orangehurst Station Fullerton, CA 92634 They would provide a set of PC boards and assembly plans if you order the Model 83SW display set for $14.00. -- Dave Turner 415/823-2001 {att,bellcore,sun,ames,decwrl}!pacbell!dmturne