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[VE3WGO]

The DPD (Digital Pre-Distortion) corrections would be applied in the digital domain, that is, before the digital-to-analog converter in the Tx path.

Icom's IC-7610 description says it uses Digital Upconversion which means it creates an true digital representation of the transmit signal at the transmit carrier frequency.  It says: "Breaking with the tradition of mixing a carrier signal with a local oscillator, a Digital-Up-Conversion (DUC) method is used to generate the required signal from the Digital-to-Analog Converter."

So the sampled RF from the PW2 needs to get digitized then processed in the 7610's Tx DSP before it gets converted to an analog signal. They likely do the DPD correction at baseband, before going through the DUC.   That's the absolute best way to clean up the entire Tx chain, from bits to antenna port.

The IC-7851 does not seem to have this feature, so apparently this new DPD capability will position the (upgraded) IC-7610 as Icom's new flagship transmitter!

73, Ed

[W9AC]

"...That's the absolute best way to clean up the entire Tx chain, from bits to antenna port.

The IC-7851 does not seem to have this feature, so apparently this new DPD capability will position the (upgraded) IC-7610 as Icom's new flagship transmitter!

73, Ed

Agreed, Ed.  I think you're correct with the DPD implementation which is a huge advancement for others to follow. 

With the 7610's Rx performance shown nearly equal to QST's recently-published Elecraft's K4D product review, and now DPD with the PW-2 (and possibly an outboard DSP processor offering for other rigs), it's difficult to justify the K4D's 2X price difference when factoring in the optional ATU.  Compare receiver and transmitter ARRL measurements between the two transceivers side-by-side.  So, two 7610's for the price of a single K4D.

FWIW, I own a 7610 but also have a K4D on order.  An ANAN 7000DLE is still the flagship rig on my desktop.

Paul, W9AC

[VR2AX]

[quote author=VE3WGO
The IC-7851 does not seem to have this feature, so apparently this new DPD capability will position the (upgraded) IC-7610 as Icom's new flagship transmitter!

73, Ed
[/quote]

I also had a look at the 7851 manuals and came to the same conclusion. I wonder if the 7851 can be upgraded to accommodate in the same way as the 7610. I find it difficult to believe that Icom intend to subjugate the 7851 to the 7610, and note the marketing video also features the 7851. Maybe I'm just looking for an excuse for a new toy, or two.

[W5OT]

Personally, as a legacy Icom radio user (one that doesn't have a waterfall display or USB ports).......I just want to know when it hits the dealers shelves.  The PW-1 that's designed to work with my radio isn't available, so I'm assuming the PW-2 WILL have the same compatibility and hoping it will be more reliable and not have some of the flaws that plagued the PW-1. (ie, power supply issues.)

[KA4WJA]

Ed,
Thanks for this further info regarding the 7610!

The DPD (Digital Pre-Distortion) corrections would be applied in the digital domain, that is, before the digital-to-analog converter in the Tx path.

Icom's IC-7610 description says it uses Digital Upconversion which means it creates an true digital representation of the transmit signal at the transmit carrier frequency.  It says: "Breaking with the tradition of mixing a carrier signal with a local oscillator, a Digital-Up-Conversion (DUC) method is used to generate the required signal from the Digital-to-Analog Converter."

So the sampled RF from the PW2 needs to get digitized then processed in the 7610's Tx DSP before it gets converted to an analog signal. They likely do the DPD correction at baseband, before going through the DUC.   That's the absolute best way to clean up the entire Tx chain, from bits to antenna port.

The IC-7851 does not seem to have this feature, so apparently this new DPD capability will position the (upgraded) IC-7610 as Icom's new flagship transmitter!

73, Ed

If I'm understanding this correctly, it appears that the '7610 isn't going to take an analog RF sample, but rather a digitized sample (such as one from the PW-2?)?

This would explain why Icom specifically is showing the IC-7610, and specifically the PW-2, working together...and not simply touting the '7610 as having pre-distortion built-in (as, even if it does, it probably wouldn't be able to include a "normal analog amp" in the pre-distortion loop?).

Maybe there is more to this, but that's my understanding so far!


73,
John,  KA4WJA