Farmerik,

I've not experienced the hiss you are reporting on my CR-1100, so I can't
comment too much on that.

I have a few comments, however, about the automatic volume control (AVC). The
Si4734, the radio chip used in these receivers, has some setup parameters for
the AVC processing algorithm. I've noticed on the PL-300 and PL-380 units that
I own, Tecsun has greatly increased a key AVC parameter from its default value.
I think this causes the AVC to be very "tight", the volume unvarying over many
conditions. This is probably fine for most users, but maybe not optimal for
DXers. In particular, I find it very hard to tune a Q-stick to resonance by ear
with my PL-380. I've been experimenting with reducing the AVC parameter to its
stock value and it definitely helps in hearing resonance changes. My
experiments are preliminary at this point and I'll try to report more later on.

I suspect that the earlier design of the CR-1100 does not include this AVC tweak
by Tecsun.

This particular effect is unrelated to the soft-mute function.

-Scott-

--- In ultralightdx@yahoogroups.com, "farmerik" <farmerik@...> wrote:
>
> I mentioned my Tecsun CR-1100,which I believe uses the same DSP chip as most
of DSP ULR's awhile back. The audio has some sort of back round hiss or noise
which I find VERY annoying. It is reduced greatly by driving an outboard amp and
speaker, but not eliminated.
> I decided to try the TERK loop, to see if that would clean up the noise.
> [I had noticed the Terk quieting backround noise on weak stations on the
G8.]
> While my G8 seems to have a total control of the audio volume, so both weak
and strong signals are heard at the exact same volume, and it is very hard to
tune the terk to peak the signal, the CR does not do that at all, and it is very
easy to fine tune the Terk for the loudest and cleanest signal.
>
> Is that the infamous muting problem?
>
> The CR can pick up weak stations, they just sound awful to my ear. FM can hear
some very distant stations, but has the hiss or noise too. There could be
something wrong with my radio, and my ears are not so good either. The good news
is that it is easy to use the Terk with the CR, the bad news is you really need
it to hide the hiss.
>
> Anyone who understands the DSP radios may be able to sort this out, and
explain it to me. - FARMERIK
>