When the front panel reads "Off:H", it means that the DSP NB is "OFF" but
blanker is still active. If you press and hold the NB button for several
seconds, both the OFF and
the H will change to "Off". If you momentarily cycle the NB button, a
number will appear indicating the
level of DSP NB that is active (use MULTI Knob to set level).
Hope this clarifies the NB issue.
Woodland Park, CO.
----- Original Message -----
From: "Leonard J. Umina" <firstname.lastname@example.org>
Sent: Monday, November 03, 2008 9:05 AM
Subject: [TenTec] Orion Noiseblanker - OFF:H is not really OFF
> SUMMARY: DISABLE THE HW NOISEBLANKER ON THE MENU/RX PAGE NOT THE FRONT
> TO AVOID OR CURE RX DISTORTION. IF YOU SEE OFF:H ON
> THE DISPLAY YOU
> IT IS NOT REALLY OUT OF THE CIRCUIT.
> I made a remarkable discovery during SS this last weekend.
> The noiseblanker in my Orion causes tremendous distortion, even when the
> front panel is OFF during times when the band is full of strong signals.
> How strong? Well I live at the repeater site, and my antennas are
> therefore at almost 1200 feet above
> Sacramento Valley. This makes up for my lack of skill as an operator,
> but it also gives me line of site to
> a number of KW stations, especially during SS. Typically I run 12-18 db
> of attenuation on the RX and a
> number of the California contest stations still run 30 over 9 here.
> During the contest the band seems alive with crud. Since I got my Orion
> about 3 years ago, I assumed
> this crud was just bad transmitters being over driven in the excitement
> of the contest etc.
> As it happened I normally use the hardware noiseblanker here because it
> works very well on the nearby
> electric fence, but I leave it off when the fence is not an issue. The
> front panel usually reads off:H
> This is key, because apparently the noiseblanker isn't really biased off
> when this is displayed.
> I've relegated my 756 MK II as a bandscope to visually monitor band
> openings. It works well for this
> and I usually dont ever listen to the radio.
> During SS the distortion was really killing me. Some of the
> transmitters seemed so darn dirty, but it was
> impossible for me to figure out exactly which one was causing the
> problem though at times I could make out
> the SS sent fast by a number of operators.
> At one point I was taking a break and having some dinner, so I shut the
> Orion down to let it cool off (more on my next posting on that subject)
> and I decided to see how the 756 handled all the crud I was hearing on
> the band. I turned up the audio. Suddenly I was shocked. I put the
> foodbag down. There was no crud on the 756!
> I turned the Orion back on and started looking at the RX menu, figuring
> one of my super settings for the AGC must be causing a problem. (The
> noiseblanker on the front panel read off:H). By accident, I disabled the
> hadware noiseblanker on the RX Menu. Suddenly the Orion's audio
> changed. I was a bit surprised by this
> since it was supposedly OFF:H on the front panel. In the next 30
> seconds I realized that the change was
> due to the crud going away!
> Suddenly the band was totally clear, and I mean clean. It was like a
> Suddenly I could run my 250 Hz roofing filter and hear QRP SS Stations
> clearly. WOW is all I can say.
> I don't think there is anything wrong specifically with my Orion. I
> have not looked at the circuit they use for the noiseblanker, but I
> suspect the front panel control signals generated by the CPU do not bias
> the circuit off properly, and if you have a new in band strong signals
> the distortion is incredible. Since the noiseblanker appears to be
> connected before the RF Gain control (just from observation) backing
> down the RF Gain never
> helped during contests, the crud was still there.
> In past contests, by accident, I probably had the HW Noiseblanker off
> sometimes by accident, accounting for
> some of my best Orion experiences. Now it will be off permanently until
> it gets fixed.
> Sorry for the long story, but if you have any RX trouble with your
> Orion, go the to Menus/RX and disable the
> hardware noiseblanker there. Even money the problem goes away - not
> just on CW.
> (Clean Sweep, 89,600 score Nov 2008 ARRL SS)
> [Imagine what a good operator up here could do]
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