Geoff Burginon wrote:

Which particular one of Collins receivers? What was the actual
specified noise floor in figures? Frankly, I doubt you can get much
lower than the WinRadio G313i -138 dBm.

Read also this:

"If I had to choose between a Collins 95S-1 and the WR-G303i (ignoring
the obvious fact that the 95S-1 tunes to 2 GHz), I would take the
WR-G303i."

John Wilson, ShortWave Magazine
(more details on http://www.winradio.com/pdf/g303i-review-swm.pdf )

And this in fact refers to the *predecessor" of the WR-G313i, which is
a much better radio still - 5 stars by WRTH.

My WR-G313i does indeed have the advertized -138dBm noise floor, and
even the S-meter reliably measures down to that level - with 1dB
accuracy.

Not speaking of the ultra-sharp continuously variable IF filters down
to 1Hz bandwith.

Now *that's* what I'd call winning the contest hands down. ;-)

Geoff

Geoff:


-143 dB was the noise floor of the R-390A, according to web info.
Otherwise, of course, it was an old tube (32 of them!) boatanchor with
mechanical tuning, weighed a ton, and had none of the amenities that modern
digital radios provide. But it WAS quiet!

--
Brian Denley
http://home.comcast.net/~b.denley/index.html

On Wed, 2 Feb 2005 23:46:12 -0500, "Brian Denley"
wrote:


My WR-G313i does indeed have the advertized -138dBm noise floor, and
even the S-meter reliably measures down to that level - with 1dB
accuracy.

Not speaking of the ultra-sharp continuously variable IF filters down
to 1Hz bandwith.

Now *that's* what I'd call winning the contest hands down. ;-)

Geoff

Geoff:


-143 dB was the noise floor of the R-390A, according to web info.
Otherwise, of course, it was an old tube (32 of them!) boatanchor with
mechanical tuning, weighed a ton, and had none of the amenities that modern
digital radios provide. But it WAS quiet!

--
Brian Denley
http://home.comcast.net/~b.denley/index.html


Thanks for the info Brian, sounds indeed awesome, I think I'd love to
own this radio (and I thought I had no space left! :-).

But frankly, I am still a bit confused about the noise floor. Yes I
did see the Web pages which mention -143 dBm and one even says
-147dBm, but some other pages specify less, for example -127 dBm,
which seems to me more realistic, considering the sensitivity specs,
which appear to be poorer than my WR-G313i (I have verified its
sensitivity with a good signal generator, and it is actually about 2-3
dB better than specified):

R-390A specs:
http://members.aol.com/tcsopr/r390a.htm
WR-G313i specs:
http://www.winradio.com/home/g313i-s.htm

How could a receiver with a higher noise floor have a better
sensitivity?

See also the original military specs on:
http://209.35.120.129/mil-r-13947b.pdf

and this table
http://www.sherweng.com/table.html
which shows the noise floor as -137dBm,
i.e. about the same as the WR-G313i.

Confusing, eh?

I also note the dynamic range of the R-390A is rather poor:
according to the specs on
http://members.aol.com/tcsopr/r390a.htm
it is only 52.7 dB (but this can't possibly be correct?),
and on http://www.sherweng.com/table.html
it is more reasonable 79dB (or 81dB wide-spaced), but it is still
nothing compared to the 95 dB of my WR-G313i...

Geoff

Id say the Lowe is quiet, but you forgot to power it up!
B

"Brian Hill" wrote in message
...

"Brian Denley" wrote in message
...
Brian Hill wrote:
"Geoff Burginon" wrote in message
news:41fe2980.12117500@news-server...
On 30 Jan 2005 19:37:29 -0800, wrote:

I started thinking about this tonight. I was tuning around with a
Lowe HF-150, comparing it with some other receivers, and was struck
by how quiet the 150 is--and by what an advantage this is when it
comes to resolving weak AM signals.

So, just out of curiosity, what's the quietest receiver you've used
and/or owned?

The WinRadio G313i by far. Noise floor -138 dBm and the continuously
adjustable IF filter let's you adjust the IF bandwidth to precisely
match the bandwidth of the signal. No other receiver comes close.

Geoff


R-390

B.H.

The Collins should win this contest hands down. Nothing, to my
knowledge,
ever had a lower noise floor. The story is that it was only limited by
the
Galactic background noise level. You can't do any better than that.

--
Brian Denley
http://home.comcast.net/~b.denley/index.html



They're pretty amazing receivers. Now if they only tuned like a SP-600

B.H.