Double Balanced Mixers, SA602A versus MC1495 or MC1496 ?

I'm trying to understand active double balanced mixers better.

1. Which if better for HF frequency transceivers, something like an SA602A or an MC1495 or MC1496? I see some designs that use an MC1496 for the receive side and an SA602A on the transmit side.

2. What dictates when one is better than the other for receive versus transmit and vice-versa?

3. Which has better IP3? I don't see it in the spec.s for the MC1495 or MC1496. Why are some mixers' IP3 values in negative db? I'm used to seeing positive db numbers on amplifiers.

4. Which is most likely to stay in production and/or are there cheap high quality active mixer alternates to either of those? I found something called a Y-mixer with less pins but I can't find it again now.

5. Why are switching double balanced mixers more common than linear double balanced mixers? I mean, if I use a fairly linear device like an AD835 and I have an L.O. input that doesn't overdrive into switching mode, and I have audio to the other input then it seems I'd have less higher frequency harmonics of the L.O. frequency. But if I drive any kind of double balanced mixer to switching mode then it seems like I'll have a lot more harmonics at higher frequencies (since the square wave shape is formed from higher harmonics) and so I'd have to low pass filter the mixer output more. So why don't people usually use a mixer in its linear range rather than in switching mode? Is it just because it is more expensive to make them have high linearity throughout the input voltage swing range?

Thanks if anyone can Elmer me on this,

George

MC1496 is designed for carrier suppression (DSB double side band modulators) but in the same time can be used as product detector, or standard double balanced mixer.
SA602 can be used as DSB modulator, but cannot provide the same carrier rejection as MC1496.

Thanks vfone.

I thought all double balanced mixers had the characteristic of carrier rejection so are you saying that is not true or are you saying it is true but that the MC1496 does a better job of it than the SA602?

Do you or anyone have insight into why it seems more common to be setting the L.O. input level into a mixer for switching mode driving of a double balanced mixer rather than using an analog 4 quadrant multiplier as a mixer with a L.O input within the linear range of the multiplier? It seems to me that the later would generate less higher harmonics.

thanks, George

Never mind maybe. I discovered the H mode mixer last night so now I'm researching that.

I think this "KISS" mixer will work and not cost me too much:

http://www.mikrocontroller.net/attac...er_Musings.pdf