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Old August 19th 03, 12:18 PM
Dave Hall
 
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Bert Craig wrote:

Hi everyone,

I hope you are all well. A while back, I'd mentioned that I'd QSO'd with a
gent who was using a DSP board. Well, I had to try it out for myself and had
SGC install their ADSP2 board into my Uniden Grant XL.

Some may say that it's like installing dual Weber side-draft 2 bbl. carbs on
a Ford Pinto 4 cyl. engine. (Actually that's been done.) Why do it? Because
I can, that's why. ;-)

Actually, the base receiver of the Grant XL is a very good platform to begin
with. It's the same chassis/board as the venerable Cobra 2000 GTL with the
same great receiver. I'd already added CBCI's Channel Guard IF filter with
good results, increased ACR. (Adjacent Channel Rejection) The ADSP2 installs
further down in the receiver chain so one doesn't interfere with the other.
(No pun intended) :-)

Well, upon powering up the radio and cycling the two microswitchs through
their positions, one thing became immediately clear...I was going to be one
VERY happy camper. There are three filter settings; voice, CW1, and CW2 as
well as two levels of DSP, hence the two microswitches. Of course, each can
be turned off completely. I find that the first DSP level is quite
sufficient and the voice filter is rarely even needed. However, when the
signal-to-noise ratio becomes unbearable, (As it has recently in this locale
on both 10m and 11m.) it's nice to be able to "kick" the filtering level up
a notch (Again, no pun intended.) or two.

Is it kinda pricey? Yeah, but it's no more than what many seem willing to
shell out for an amplifier and its 100% legal. Here's the website. Hope this
helps some of you, take care. :-)


Hi Bert!

Glad to hear that this was a worthwhile experiment. That was always the
best part of CB for me, the experimentation factor. I wish more people
would play with their receivers, rather than the transmitters. It'd be a
whole lot cleaner out there.....

Have you done any parametric testing, or has all of your testing been
subjective, on-air stuff? I'd love to see some hard data, on the degree
of improvement over stock.

Is this practical? Well, you certainly could get a ham quality receiver,
which would probably do it a bit better, for only an incidental increase
in price. But you wouldn't have the satisfaction of saying "i done it".

The question of legality is also interesting. On the one hand, the FCC
takes a dim view (I.E. it's usually illegal) of ANY mods to a type
accepted radio. In practice though, it's usually the transmitter that
they're most concerned with. You could always use one modded receiver
for receive, and another unmodded radio to transmit, and that would be
legal.

Dave
"Sandbagger"