"Dave Hall" wrote in message
...
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!
Hey Dave.
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.....
Thank, Dave. I was never into power increasing or freq. expansion mods,
however, I too am not without sin. More on that later. 0:-)
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.
No, I haven't...which is pretty much why I had SGC perform the installation
and testing. After speaking with the folks at SGC, I knew that they had the
equipment to not only get it done...but "get it done right!"
Is this practical?
Nope, but that was part of the allure.
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".
Exactamundo!
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.
I take a common sense approach. While I'm reasonably certain that the
receiver mods are 100% legal, I do have an on-board speech processor
installed. I use the SP-1a and I'm very pleased with the resulting audio. I
could've gone with Astatic's external model, but since even the addition of
an amplified mic can (and has) be arguably construed as a modification to
the type-accepted transmitter section, and thus technically illegal, I chose
to apply a little common sense here as well, Thus the rig is clean, clear,
and I'm quite comfy operating it at it's whopping 12 Watts P.E.P. (What's
AM?) HOWEVER, a stock Grant LT also sits right next to it. ;-)
You could always use one modded receiver
for receive, and another unmodded radio to transmit, and that would be
legal.
Truth is, I'm one of those folks who listen 99.99% of the time and transmit
the other 0.01%. Except between 7.1 and 7.15 MHz on the Novice/Tech"+"
sub-band. Tryin' to get my "key" on. :-)
Take care and thanks for the comments.
Dave
"Sandbagger"
--
73 de Bert
WA2SI
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