Thanks gentlemen, swaying towards the IC-R75 at the moment, cannot work out why the transceiver version the IC-718 is cheaper though, around AUD$848.00 compared to AUD$900.00 for receiver.
Also been reading up on the AOR AR8600 Mark-2, lot of for and against.
Perhaps the price difference is because the IC-R75 has been discontinued?
Even when both were still being made, the 718 was about the same price as the R-75, and often a bit less expensive than the RX only radio.
However, the 718 is not a "transceiver version" of the R75, although it is often taken as one. The 718 came out of the same design house, and roughly the same time as the R75, so there are similarities. But the two receivers (ignoring the transmitter section) are different.
Start with the fact the R75 is a triple conversion receiver, while the 718 is a double conversion machine. Without even going to the schematics that should tell you there are some pretty significant architecture differences. And the two radios have different tuning ranges.
If you go to the schematics you will see that some of the individual sub-circuits are similar or identical, not uncommon with engineers being creatures of habit, if something works, and applies, use it again. However, they are laid out differently on the boards, use physically different components, and things like noise and isolation are better controlled with the R75 configuration. The R75 is just better (as a receiver) laid out and assembled.
I never owned the IC-718, however I did borrow a friends radio for a few weeks. I have, and do, own a couple of R75s. I have used the two radios (718 and R75) side-by-side. I never did hard bench testing of performance, but in general I found the R75 noticeably the superior of the two. With the two radios side-by-side I still reached for the R75 before the 718. I found the R75 to be more selective and less noisy. It appeared to have superior dynamic range.
Working from memory, there are a few feature differences. I don't remember them all, but a couple stuck out. For example I don't remembers the 718 having twin PBT (it did have IF shift, but not PBT), while the R75 does. The added optional filter support is different, the 718 will only take a single added filter in the 455 kHz IF, while the R75 will take an added filter in each the 455 kHz and 9 MHz IFs.
Having used both, and considering only the want for a receiver, I would take the R75.
Really, I wish Icom would release an HF only version of the R8600. I absolutely love my R8600, it is an excellent radio. But at the price point I probably will not purchase a second unit. However, if Icom could make it HF only (maybe call it the R-86?) and reduce the price by something on the order of 60% or more I would be really tempted.
T!