[CQ-Contest] TenTec Orion questions regarding SO2R suitability

[Eric Scace K3NA]

   TenTec is promoting the Orion as the best radio for contesting to date, based on the receiver measured performance parameters,
and the flexibility in the "full dual receive" capabilities with the transmitter.  The website states, in part, ""Instant Two Radio
Mode" allows ORION to instantly QSY between two different bands. Two linear amplifiers, two sets of accessory devices via dual band
data outputs and two antennas can optionally be connected to ORION to allow instantaneous QSY (useful for seeking out and working
stations on one band during a contest while CQing on a different band, for example)."

   Sounds great, eh?

   I have my doubts, and would like more information from those who have used the radio.

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POTENTIAL PROBLEM #1:

   After reviewing the website and owners manual, it appears the main receiver's signal processing chain is used while transmitting.
So, one can NOT use the main receiver while transmitting.

   There is nothing that indicates whether the sub-receiver continues to operate while transmitting.  If the sub-receiver is also
disabled during transmission, then the Orion is NOT a "SO2R station in a box"!  One will still need a second radio to implement an
SO2R contesting station, since it is essential to be able to receive (at least on a different band) while transmitting.

   Finally, if one is transmitting on the sub-receiver's frequency, the manual implies that neither the sub-receiver nor the main
receiver can be used during the transmission.  The sub-receiver will have to be muted during the transmission... and the main
receiver's signal processing chain is in use by the transmitter.  So the box is completely mute.

   Can an Orion user clarify if any receiver continues to operate while transmitting?

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POTENTIAL PROBLEM #2:

   The website data lavishes praise on the very promising receiver specifications... but I see in the fine print that the
sub-receiver's performance is FAR below the main receiver.  To wit:

	5 kHz 2-two 3rd order dynamic range / 5 kHz spacing IP3
Orion:	101 dB / +24 dBm
K2:	88 dB/ +1 dBm
FT1000MP Mk V:	73 dB / -5.2 dBm

   Sounds great, eh?  But look a little further...

Orion main receiver:
   IP3: +25 dBm for 20 kHz spacing, 2.4 kHz bandwidth, pre-amp off.
      +24 dBm for 5-kHz spacing, 0.5 kHz bandwidth, pre-amp off.
   IMD3 dynamic range: 101 dB, preamp off, 20- and 5-kHz spacing.

Orion sub-receiver:  far fewer details given, but...
   IP3: +5 dBm typical, 20 kHz spacing.  (no clue about bandwidth used in this measurement)
      ... also no 5 kHz spacing figures at all.
   IMD3 dynamic range: unspecified.

   That 5 kHz spacing IP3 figures will be worse than 20 kHz spacing for the sub-receiver because the sub-receiver doesn't employ the
same crystal roofing filter scheme as the main receiver.  Basically, there isn't any clue as to where the sub-receiver falls in the
spectrum of modern receivers!

   Does anyone have better specs for the sub-receiver?

   So, as a SO2R operator, one gets to use the excellent receiver -- but ONLY when not transmitting!

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   Based on what I've seen so far, it seems like TenTec missed its implied goal: two excellent, independent receivers and one
transmitter in a configuration that can be used as a SO2R station in a single box.

   Am I missing something here?

73,
   -- Eric K3NA