planning tool needed

Can someone recommend a handy frequency planning tool for things such as double-conversion or multiple-conversion radio?

Thanks a lot.

It may sound like an old question. I am still interested in any possible comments or suggestions. Thanks.

that is very complex. You need some tools to calculate the spurs, then select a safe area to operate.

Could you recommend a few please? I am trying to find some online freebies.

Appcad has a spur calculator I believe and is free.

Keith

It is a very nice handy tool. Thank you very much Keith!