Joe:
With Block LMS selected for both NR and ANF, I cannot confirm anything
like a 6 dB of insertion loss.
I put tones at many different levels into the front end of the radio. I
turned on NR. The output volume for a tone was the same. I turned to
voice, the noise was reduced but there might have been 1 dB of
reduction in the voice, but nothing like 6. I tuned to an SSB signal
that had a tone interfering with it. I turned on the notch. Within a
second, the tone was gone, the voice was there.
I tuned to a broadcaster on 40 meters. I put the radio into DSB. I
put the carrier within -300, 0, 300 Hz of the correct frequency. I
turned the ANF (Block LMS) on. The carrier was notched in each case and
the voice was essentially untouched.
I just cannot confirm using test equipment, or on the air, what you are
seeing.
Bob
Joe - AB1DO wrote:
Bob,
both the block LMS NR and ANF are outstanding. However, back in preview 12
when it was introduced I reported that block LMS ANF reduces the total (SSB)
audio volume significantly (with no carrier present, quick and dirty
observation on my Delta 44 mixer panel shows about 6dB reduction between ANF
on/off ), but I didn't hear whether anyone else heard or saw the same thing.
Although the carrier killing capability of the current block LMS ANF is
truly outstanding, it still reduces the audio volume by about 6dB.
Am I missing something or do I have some setting wrong? I know you mention
below a 6dB reduction of gain, however my guess is we're not talking the
same gain?
On the off-chance that my observation is correct, would it be possible to
compensate for this post ANF?
73 de Joe - AB1DO
B
--
AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats,
NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman
Laziness is the number one inspiration for ingenuity. Guilty as charged!
