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Old October 7th 04, 04:31 PM
Lucky
 
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"Mark S. Holden" wrote in message
...
Michael wrote:

"Lucky" wrote in message
...
Hi gentlemen

It looks like I've narrowed my next radio down to these two. I did bid
on
a Harris RF-550 last week but my $606 bid got taken out.

I'll be using the receiver for AM BC during the day, and local Hams and
DX'ing at night into the wee hours. I know the R8a has selectable
sideband
and AM sync if I'm correct.

But the R75 is supposed to be extremely well built and I can get free
DSP
and a rebate for $50 coming out to a $475 final price. I think I can
pick
up a R8A for about $500 to $600. So the price difference may not be
that
huge at all.

The only thing is that the R75 will be brand new and the R8a used.

So what do you guys think? What bothers me about the R75 is I hear the
AM
audio is just not too great and you need to work around it.
Some people say the AM sound is not that bad at all, but most others
say
it needs help.

I need your experience and opinions please?

Thank you
Lucky


Hiya, Lucky

I think you should go with the shiny new out of the box R-75 instead of
the
used R8a. First off, it is always nice to have a brand new radio vs.
one
that has been used. Along with that, I think you will get more out of
the
R-75. I use an R-75 as my primary radio, and I have also had my friends
R8a here for several weeks, so I know how both radios sound and perform.

When the R-75 is in its stock form with no mods, it has two shortcomings
when compared to the Drake R8a. The first being, that the R-75 does not
have the fantastic audio quality of the Drake R8a. This is true, but the
audio quality of the R-75 is not bad. It is just not as defined and rich
as
the R8a's audio. If you want the audio definition on the R-75 to be
enhanced, you can do so by sending it to Kiwa to have a very simple,
inexpensive and fully reversible mod done on it. They offer a mod for $
35.00 and they will have your radio back to you in less then two weeks.
I
had this mod done to my R-75 and it was back to me in a week.

The second shortcoming of the R-75 is that it has an am sycn detector
that
isn't very effective in its stock form. Once again, you can improve this
quite a bit by sending it off to Kiwa for yet another simple, inexpensive
and reversible mod. The offer the sync detector upgrade for $45.00. I
also
had this done to my R-75 and it improves program listening under
conditions
of fade quite a bit. The sync now holds its lock quite well and it
really
helps keep distortion in check.

See Kiwas R-75 web page: http://kiwa.com/R75.html

I have those upgrades done on my R-75. I also use an external speaker
wich
is a must on both the R8a and the R-75. I can say that my R-75 sounds
VERY
good for program listening. The R8a may still have a bit more rich and
defined audio, but not by much !!!! Also... No am synch detector will
help
you if you are listening to a signal that is extremely weak and messy.
You
can expect a good am synch detector to help you with a signal that is
slightly or moderately messy. The modded R-75 am synch will do exactly
just
that for you. If you really want to dress up your audio, you can run
your
line out audio into your PC sound card and then into a software driven
mixer. I do that from time to time when I have a signal that is really
muffled or has way too much base or is too tinny. Then, I can use the EQ
and really dress it up. You can do that with any radio :-)

So... There you have the shortcomings of the R-75 compared to the R8a,
and
how to fix then for little cost should you decide to. Now... Here is
where
the R-75 really shines :-)

If you like to listen to hams, or utility, the R-75 is the radio to do it
with !!!. I think the R-75 is probably the best ssb rig you can get
without
having to spend about $2,000.00. You've probably heard already about
the
twin PBT :-) No question here... You can tweak and resolve signals with
this in ways that you cant do on the R8a. No mod to the R8a will enable
it
to do what the R-75 can. Also... With the superior ssb
function/capabilities of the R-75, you can also use it to listen to
really
weak and messy sw broadcasts signals using ecss tuning, and then use the
twin pbt to tweak it up and get it to sound good enough for your ear to
make
out what is being said. That is what makes it such a great DX rig. It
is
rock solid stable and it has the tools to really dig out and resolve the
weakest of signals. For anything to do with ssb, or DX'ing, I'd take a
used
R-75 over a brand new R8a... LOL :-) And.. Lets not forget, with a few
mods, you can have quality program listening too.

Hope that helps....

--
Respectfully,

Michael



I'd feel better about the R75 if the factory incorporated the sync mod
into future production.

The standard filter for sideband is narrow for my tastes at 2.1khz. The
Drake is slightly better at 2.3.

Wider filters can give improved fidelity, although if they don't have
steep enough skirts, you won't like them. My Harris RF-550 and AOR 7030+
have 3.2khz filters. They sound beautiful without adjacent channel
problems. Don't know the shape factor on
the Harris filter, but the 7030 one is 1.33. (It's a crystal filter, made
for the Racal 6790/gm)

Icom does sell a 2.8khz filter for $140 and a 3.3khz filter for $160.
It's not practical to change filters on the Drake.

But an R75 with the Kiwa mods and an extra filter will cost more than
Lucky bid on the Harris. The advantage is he could do it in stages.

If I'm dealing with a reputable person, I'm not afraid of used radios.


Hi Mark

Too bad I lost that Harris but $745 total from Esoteria right now is too
much for me. I agree that 2.1 is narrow but I thought there was a 2.4 stock
filter? I got this from the Yahoo R75 newgroup. Is he right or wrong?

"The stock R-75 comes with 15kHz and 2,4kHz in the 9MHz section and
15kHz ,6kHz, 2,4 kHz for the 455kHz. I added a 3,3kHz FL 257.

15/15 is always too wide, 15/6 might be too wide for some stations
with a second station nearby (9kHz spacing and overlapping spectrums),
15/2.4 sounds very dark.
2,4/15 is useless, 2.4/6 too dark, sometimes ok for news....

The list is endless.

The 2,4 setting is quite good for SSB (in order to avoid the almost
non existing feature of the Sync detector you can use this as ECSS),
3,3kHz offers an excellent choice for both sound quality AND selectivity.