Interesting use of CMOS IC 4066 in RF transceiver

Hi, I have never seen before any CMOS IC used in a core part of RF circuit like this: https://www.qsl.net/p/py2ohh/trx/goitacas/goitacas.htm This 7MHz transceiver uses 74HC4066 IC as a receiver, buffer driver etc. I can easily find the transient frequency of a transistor in datasheet but I have no idea about maximum working frequency of such CMOS IC with the help of datasheet. The chip 4066 has lots of variations, I know some cannot work in 7MHz. I think newer version of 4066 are MC14066BCP, than 74HC4066. Help me to find out the maximum working frequency of MC14066BCP, for example in the basis of such transceiver (link above). Or does the MC14066BCP has capability of working in the transceiver? I guess the MC14066BCP is the product of Motorola (?). The logo "M" looking like so. Picture uploaded.

An MC14066 is an ordinary old CD4066. A 74HC4066 is much faster (higher RF frequencies), has a much lower on-resistance and has a supply voltage limit much lower.
The absolute maximum supply for a 74HC4066 is 6V but the circuit you found wrongly powers it from almost 8V.

Apart from the strange use of a '4066, there are several weird things about that circuit.

I ask myself, "is there anything in that circuit that I would copy?"
The only answer I could come up with is "The voltage regulator".

JimB