MC4046 PLL as FM demodulator.

[Geordie McBoyne]

The TI application notes for the 4046 PLL integrated circuit suggest the device can be employed as an FM demodulator. Would this device operate satisfactorily at 10.7Mhz?
Easy enough circuit to try out in a receiver.

Geordie McBoyne.

[ppppenguin]

The standard 4046 won't work at 10MHz. Or at least not very well and only at the higher end of its voltage range. The HC or HCT version will work at 10.7MHz with ease. I've used them at 27MHz, though only the Philips branded ones were reliable at that frequency.

Ought to say that I was only using the VCO part at that speed. The phase comparison was done at a much lower frequency.

If you want some of the Philips HC/HCT parts I'm pretty sure I have them in the stores.

[Mike Watterson]

The 4046 is a vintage solution. Or nearly as it must be nearly 50 years old. It's slow.
There are much newer & better ICs, cheap, and working over 120 MHz.

I'm amazed ones worked at 27 MHz. Less than 4MHz was typical. But that was only the VCO!

[ppppenguin]

Only the HC/HCT parts worked at 27MHz, and then only the Philips ones were reliable. The HC/HCT221 dual monostables also had wide variation between makes. Whereas LS221 was utterly predictable. Of course good design doesn't use monostables but there are some jobs that are a nuisance to do any other way.

[Geordie McBoyne]

The 4046 PLL ICs I have here are RCA CD4046. Date code 849, that could be 1989? Radiomuseum states first use in 1979, surely before that. It's definitely a 70s device.
https://www.radiomuseum.org/tubes/tube_cd4046.html

Geordie McBoyne.

[ppppenguin]

I think 4000 series CMOS was late 70s. Some parts may still be in production.

[jimmc101]

I think 4000 series CMOS was late 70s. Some parts may still be in production.

I feel old, I remember the original ceramic parts.
It was introduced by RCA in 1968. see Wikipedia.

Jim