The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

I reprogrammed the pins on the 858 chip to give the 5 kHz channel increments. On frequencies below CB channel 1, 26.965, in the 5 kHz mode, there is a 2500 Hz tone on both TX and RX. The amplitude is less than 1% audio. The other frequencies do not have this. The 5 kHz channels above 40 are fine. Has any one else encountered this?

I would suspect that the VCO may need a slight touch up. It is probably best to simply align the whole PLL while you are at it. I remember doing some exotic mods to the 858, 861 etc. many years ago, and actually hearing notes being played as the channel selector was rotated, each click of the switch sent the frequency of the tone higher.