Trucker wrote: if/when, they add predistortion, in the 7610 firmware, that they would allow it to work with or without the new amplifier
Props to ICOM if they decided to do this - but I can almost guarantee - this will never happen - why?
Because Icom is a very marketing ($$) driven company.
The 7610 had been around for years - it’s not new - but it’s a dam good radio and even TODAY there is a high demand for this "old" radio which is quite unique.
(Just shows you how ahead of its time it was)
Icom has never (to my best knowledge) has done a
major "functionality" update in their radios via firmware only. To date both the 7610 and the 7300 have had limited firmware enhancements.
A DPD enhancement - would be a major feature - worthy of a new model number for a stand alone radio - perhaps a 7620?
If Icom enables DPD on the 7610 standalone - it will be a "different radio" - so they can charge an incremental $ for the new features.
By locking the PDP functionality - to only work with the PW2 amp - they in effect are holding all the cards for much more $$
It’s aimed at SO2R market and that means operators who take this hobby seriously and have some big $$ to throw towards the appropriate station hardware.
It’s very clear from the Icom marketing to date, that they have chosen the 7610 to be "THE" radio for use with the PW2 and making the point that the DPD function will be via a 7610 firmware update to work with the PW2 only. This means if you want the PW2 to have DPD output - you MUST use the 7610 with it.
Hope you can see the logic behind this.
It is why they are unlikely to make the 7610 as a standalone DPD radio.
As a side, the output on the 7610 is squeaky clean - even without a dedicated DPD functionality - its already doing some good processing.
The real benefit of having the DPD on the 7610 (or any other radio driving an amplifier) is not to enhance the output of a already "clean" radio - but to make sure any external high power amplifier is as squeaky clean as the radio itself.
What better way to promote a "new" amplifier - the PW2, than introduce DPD to make sure its super-efficient and super clean!
The easiest way for Icom to do this is via the 7610 and locking this to thew PW2 for a great SO2R system.
Here is some speculation on how they are likely to do the "locking" of the 7610 to the PW2 ....
I think this will be done digitally.
The interface to the PW2 from the 7610 is via a multi pin control cable. This is most likely to be via one of the digital I/O sockets on the 7610.
Thinking conventional - we would expect some sort of RF sampling (-50db) from the PW2 to the 7610 - for the DPD system corrections which need to be created by the "exciter" - the 7610 in this instance. So how do they get the RF back to the 7610?
Perhaps they don't have a direct RF feedback.
They could sample the RF in the PW2 internal circuitry and quantize the output - this is relatively simple - because there is no processing - just quantizing and the digital "stream" can be fed back to the 7610 via the digital I/O for the 7610 to use in the firmware to realize full DPD functionality.
If this type of interface is adopted, Icom solves 2 problems - in effect rendering the 7610 useless on its own as a DPD system and at the same time "locks" the radio to work only with the PW2 as a DPD system.
All this is guesswork.
But if faced with the above task - get the DPD working with the 7610 locked to the PW2 - that's probably the best way to implement it!