[TenTec] Noise and ORION II

[Adam Wade]

From: dl2rdh at aol.com
Subject: [TenTec] Noise and ORION II
To: TenTec at contesting.com
Message-ID: <8CB95F0BD9837B2-9CC-315B at webmail-dh06.sysops.aol.com>
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> I find the NR of the ORION II poor. To my ear the noise of the Orion II
> in SSB is very aggressiv and the NR ist unusable while not doing
> much to reduce the noise. I am setting AGC and RFGain. I must
> reduce the RF-Gain to "60", while the bands are too noisy. This is
> my subjective opinion.

I have an Orion I, and have tried both the 1.x and 2.x firmware.  I have found a similar issue with the 565, which is not too surprising when you consider that the 565 and 566 are very similar radios, with (according to Ten-Tec) the same RF hardware and (I believe) the same DSP setup.  I have not found the onboard NR to be at all useful in just about any situation or mode, and I'd say it has improved signal quality at best around 5% of the time I have needed NR.

My current workaround is a Timewave 59+ outboard DSP processor, which also solves the low AF output problem into 32 ohm headphones that I had been having.  I am planning on upgrading soon to a Timewave 599zx, which has all the features for use with the Orion that I find lacking in the 59+ (adjustable NR aggressiveness, bi-channel NR for stereo phones, filters specifically for more modern digi-modes).  I still wish that I could have decent NR inside my rig (shoot, my old FT-100D had better NR than my Orion does, and in some ways it was even better than what I get with the Timewave 59+), and further, I wish that modern rigs would have something that's been in commercial studio audio processing gear for decades -- a "side chain".  A side chain is a line-level output between preamp and audio amp (it has other meanings when used with gear like compressors, but I won't get into that here) combined with a line level input, essentially letting you insert a
 line-level audio processing box before the AF gain knob, almifier, and speaker(s).  This would let me have my binaural receive, put a receiver in each ear, have a different output on the speaker than in the phones, and have a line level out on the back panel that had audio processing while simultaneously having that signal available through phones or speaker.  I could just insert an NR box of my choosing into the signal path without disrupting my output flow from the rig.  With the 59+, I have to set the rig's volume knob appropriately to feed the 59+, and then I can choose between monaural phones and an external speaker, and I have to take "line out" from the 59+, which means it is now affected by the AF level setting on the Orion.  The 599zx will take care of the binaural and different rcvr in each ear issue, but not the other two.  And further, I lose the ability to have my audio monitored, because I have a choice between processing the monitor audio
 through the 59+ or not hearing it at all, neither of which is a suitable answer for me.  Because inp[ut volume is often quite a bit higher than output volume with the NR turned on, any simple mods I make to solve that issue would generally result in me getting blasted out of my chair by the high volume level I'd have with bypassed audio coming to my phones.  The 59+ also always has its high pass/low pass filters engaged when in operation, so it rolls off everything below 400 hz, which I really do not like either.
Ultimately, if the 599zx turns out to be the real answer for my NR needs, I may just rewire the Orion such that I send two channels of line level (taken from the Orion before the rear panel outputs) to the 599zx input, and take the line level output from the 599zx and inject it back into the signal path just after where I took the feeds from the Orion in step 1, thus hard-wiring in a side chain.  I don't know how well this will work, considering there will be variable signal levels depending on signal strength of received signals.  But it does sound like the only real answer to integrating good DSP NR into the rig, something that Ten-Tec should have given us built in.  It is IMHO the one most glaring flaw of the Orion line (and in a close second place is the extremely slow speed of the data in/out through the serial port for rig control, and as a corollary, the fact that there are a number of controls on the Orion that cannot be accessed by rig control
 software, like the band stacking registers and the manual notch filter, for instance).
 ! Adam Wade -==- AF6ME -==- Ten-Tec Orion & SteppIR BiggIR Mk III !
! "I write down everything I want to remember. That way, instead  !
! of spending a lot of time trying to remember what it is I wrote !
! down, I spend z time looking for the paper I wrote it down on." !
!       - Beryl Pfizer    -=-    http://www.allthings550.com      !