On 17 Mar 2005 18:09:44 -0800, wrote:

What does being tube or transistor really have to do with how good the
reception of a receiver will be anyway? Nothing, as far as I know.

Nothing really...There are good and bad of both types...
The real deal in hearing something like that is selectivity.
And unfortunately, that usually means more $$$$ for the radio..
Balderdash!

http://www.broadcasting-history.ca/e...ceiver_lrg.jpg

''Probably the most revered receiver from the 1950s and 60s was, and
still is, the Collins-designed R390A/URR. Made by several
manufacturers under contract to the U.S. military, this radio was once
considered "Top Secret" because of its exceptional performance.

Many serious broadcast DXers managed to get their hands on the famed
R390, and the receiver is revered by many as superior to the
solid-state radios produced today. Hundreds of them have been restored
and maintained, and occupy prominent places in the homes of DXers all
over the world.''

''A personal experience which speaks volumes about the performance of
a properly working R390A happened only a few years back. A group of
some of the "heavy hitters" in the SWBC DX community, myself included
went on a DX'pedition to Cape Hatteras, NC. Known for its incredible
radio conditions as early as 1902, Cape Hatteras was the scene of some
of the early research done by radio pioneer, R.A. Fessenden. Today,
this remote location is a top choice for Medium and Shortwave
Broadcast DX'ers.

Quite an array of receivers had been brought along including a Drake
R8 and R8A. A pair of Watkins-Johnson HF-1000's, an R388, R390A and a
JRC NRD-535. It was a particularly good morning with extraordinarily
quiet conditions and a strong opening into the Pacific and Asia.
Around 1130 UTC I checked 3304.8 for the Radio Republic Indonesia
outlet in Dili, once Portuguese Timor. Although it had not been
reliably logged since the late 70's, it was there that morning weakly,
just a het in the R8A.

Everyone quickly tuned to the frequency determined not to miss the
opportunity to log such a rare station. However, even the $4,000
Watkins-Johnson receivers could not extract more that a few words of
copy. Our R390A was equipped with a Sherwood SE-3 synchronous detector
and I quickly tuned to 3304.8.

The R390A and Sherwood SE-3 extracted recordable audio from that
signal when no other receiver we had could. That put the receiver in a
whole new category not only for me but the others in attendance.

Of the R390A's I own, 3 are capable of sensitivity performances in the
..07-.08uv for 10db S/N + N using the 4 kc filter and standard AM
detection. I know of few receivers available today at any price able
to duplicate of that level of performance''

http://www.r390a.com/html/history.htm

You still haven't explained how the tubes fiqure into this...
Of course it's a good receiver. It was pretty much a lab
instrument. But it's the overall attention to detail, rather
than the use of tubes that makes it good. If the one
picking up the het couldn't get the audio, it's due to
poor filter shaping in that radio..
The sensitivity pretty much means nada for him in Fla.
You'd have to be on a frozen desert Isle to have quiet
enough cdx to take advantage of that sensitivity on MW.
Severe overkill for 99%...I'm sorta dubious of how those
numbers were measured also, but thats another story...
Doesn't really matter as even 1 uv for 10 db s/n+n is overkill
in the MW band..
I don't dispute that it's a good radio. It's one of the best.
But the same could be done solid state, if they still built
radios like collins did 50 years ago...
The sensistivity on my icom on MW-AM is way less than those
numbers, and I still have way more sensitivity than I could
ever use, unless I was waaaaayyyy out in the sticks , in the
dead of winter...And even then, I probably have enough..
In his case in Fla, just having a R-390 alone is not the answer.
His location is not quiet enough to take advantage of any
great sensitivity numbers.
The only thing he needs is good selectivity. Any half decent
radio, tube or s/s, will have enough sensitivity if any kind of
decent antenna is used. The station will either be there, or
it won't, due to cdx. If it isn't, nothing he uses will likely help too
much.
On HF, the 706g does .15 uv for 10db.. .12 on six meters.
..11 on vhf/uhf.. Thats overkill for HF and six...I never use
the preamp...It's *too* much sensitivity, so I actually use less
than those numbers ..Those are with the preamp on.
It's reduced on AM mode, how much depending on the band,
but it's still never lacking for sensitivity. Not even close.
And it's a fairly cheap radio, relatively speaking. Much less
than the R-390 when it was new...About 1/20th the size and
weight...:/
BTW, I do have both tube and solid state radios, so it's not
like I've never used a tube rig before to compare...
Receiving wise, there is nothing done with tubes, that can't be
done with solid state. Now audio....That's open to real debate..
I don't deny many tube radios have great audio to the ears.
But so does my 706 if I'm going into the sound card, and to
my kenwood stereo audio amp, good speakers, etc...
It's my best sounding radio for listening to the "rack" crowd,
that run all the transmit audio gear. Way better than my old
all tube Drake R4, which sounds thin in comparison, due
to it's filtering. Not much low end on that radio...
MK

On 18 Mar 2005 22:48:00 -0800, wrote:

You still haven't explained how the tubes fiqure into this...
Of course it's a good receiver. It was pretty much a lab
instrument. But it's the overall attention to detail, rather
than the use of tubes that makes it good. If the one
picking up the het couldn't get the audio, it's due to
poor filter shaping in that radio..
The sensitivity pretty much means nada for him in Fla.
You'd have to be on a frozen desert Isle to have quiet
enough cdx to take advantage of that sensitivity on MW.
Severe overkill for 99%...I'm sorta dubious of how those
numbers were measured also, but thats another story...
Doesn't really matter as even 1 uv for 10 db s/n+n is overkill
in the MW band..
I don't dispute that it's a good radio. It's one of the best.
But the same could be done solid state, if they still built
radios like collins did 50 years ago...
The sensistivity on my icom on MW-AM is way less than those
numbers, and I still have way more sensitivity than I could
ever use, unless I was waaaaayyyy out in the sticks , in the
dead of winter...And even then, I probably have enough..
In his case in Fla, just having a R-390 alone is not the answer.
His location is not quiet enough to take advantage of any
great sensitivity numbers.
The only thing he needs is good selectivity. Any half decent
radio, tube or s/s, will have enough sensitivity if any kind of
decent antenna is used. The station will either be there, or
it won't, due to cdx. If it isn't, nothing he uses will likely help too
much.
On HF, the 706g does .15 uv for 10db.. .12 on six meters.
.11 on vhf/uhf.. Thats overkill for HF and six...I never use
the preamp...It's *too* much sensitivity, so I actually use less
than those numbers ..Those are with the preamp on.
It's reduced on AM mode, how much depending on the band,
but it's still never lacking for sensitivity. Not even close.
And it's a fairly cheap radio, relatively speaking. Much less
than the R-390 when it was new...About 1/20th the size and
weight...:/
BTW, I do have both tube and solid state radios, so it's not
like I've never used a tube rig before to compare...
Receiving wise, there is nothing done with tubes, that can't be
done with solid state. Now audio....That's open to real debate..
I don't deny many tube radios have great audio to the ears.
But so does my 706 if I'm going into the sound card, and to
my kenwood stereo audio amp, good speakers, etc...
It's my best sounding radio for listening to the "rack" crowd,
that run all the transmit audio gear. Way better than my old
all tube Drake R4, which sounds thin in comparison, due
to it's filtering. Not much low end on that radio...
MK

The front end (tracking preselector, RF amp, Mixer) makes abig
difference. As does the absolute silence of the circuitry.

David wrote:

The front end (tracking preselector, RF amp, Mixer) makes abig
difference. As does the absolute silence of the circuitry.

Still, no one mentions where the tubes come into play...
All the above could apply to my old drake R4...Except I
disagree about the absolute silence of the circuitry...
Nothing is absolutely quiet...
The front end (tracking preselector, RF amp, Mixer) of my
kenwood TS-830 is very good, and it has no tubes...
Are you telling me it would be better if I converted those
circuits to tubes? Sorry, I just don't buy it...
The R-390 is a great receiver because it was a *very* expensive,
carefully designed radio made for commercial/lab and gov use.
Not because it has tubes. I can list a whole slew of other
all tube models that are fairly pathetic in performance
compared to the collins.
Why didn't the use of tubes help those models?
MK

On 19 Mar 2005 14:13:51 -0800, wrote:


David wrote:

The front end (tracking preselector, RF amp, Mixer) makes abig
difference. As does the absolute silence of the circuitry.

Still, no one mentions where the tubes come into play...
All the above could apply to my old drake R4...Except I
disagree about the absolute silence of the circuitry...
Nothing is absolutely quiet...
The front end (tracking preselector, RF amp, Mixer) of my
kenwood TS-830 is very good, and it has no tubes...
Are you telling me it would be better if I converted those
circuits to tubes? Sorry, I just don't buy it...
The R-390 is a great receiver because it was a *very* expensive,
carefully designed radio made for commercial/lab and gov use.
Not because it has tubes. I can list a whole slew of other
all tube models that are fairly pathetic in performance
compared to the collins.
Why didn't the use of tubes help those models?
MK

Dynamic range. Overload immunity.

Why didn't the use of tubes help those models?
MK

Dynamic range. Overload immunity. ...........

Because of tubes? I dunno...All of my radios have
good enough dynamic range, and none overload...Tube,
or solid state...That doesn't tell me too much...
Only cheaper radios have poor dynamic range, and
overload...:/
But, we ain't talking about R-390's. We are talking
about tubes themselves vs solid state..
I'm still waiting to hear why the use of tubes
didn't help some radios to avoid being pieces of junk...
If tubes themselves are so great, *all* tube radios
should be about on the level of a R-390. But they ain't...
Not by a long shot. The old collins/R390's, etc, etc,
and the collins A and S amateur line, and the older 4 line
drakes are about the only tube radios that I still consider
worth using. All the rest are basically junk, for
my needs. I'm sure this will attract flames 0-plenty,
but I'm picky. I demand *very* good stability.
The collins and drakes basically used the same type
of circuitry. A collins or drake is just as stable
at 30 mc as it is at 3 mc. And the readout scale is
the same also..You can't say that for many other
old tube rigs. I can think of a few that are best
used as doorstops...Unstable at higher freq's,
and drifty as a Chicago snowstorm.
Both my kenwood and icoms can be turned on dead cold,
and never need to be retuned to clarify a SSB signal.
Ever. I can sit on freq for weeks at a time,
and never have to touch up my tuning..."Sure, they
may microdrift with temp changes, but it's never enough
to notice by ear" Most tube rigs can't do that.
I know my drakes can't. They can come close, but after
about a day, you will usually need to touch up the
tuning a tad. I don't know how a R-390 fares
in this regard, but if it's *rock* stable, it's the tube
exception to the rule. And if it is, it's probably cuz
it has a xtal oven, etc...Not cuz it uses tubes...
I won't mention that most of my tube gear needed annual
alignment tweaks and tube checks/changes to keep 100%
up to par.
My solid state rigs never change...Don't have to be fussed
with every few months, if you leave them on all the time
like I did/do. I still like tube radios, and still have a few,
but I'm not blind to reality...There are not many tube radios
that are up to R-390 standards. Tubes look warm, and may add
slightly to the BTU rating of the heating system in the
winter, but they ain't the magic answer to SW-MW nirvana...
Heck, I hardly use mine anymore..Overall, I find them inferior
for *everyday* use. IE: readout resolution, stability, tuning
rates, memories, heck , I could go for days...
The R-390 is a great radio, but not all tube radios can
claim to be R-390's.....Quite possibly none can. The collins
and drake ham radios are fairly close though. But neither of
those were cheap radios when they were built either.
MK

On 20 Mar 2005 02:15:39 -0800, wrote:

Why didn't the use of tubes help those models?
MK

Dynamic range. Overload immunity. ...........

Because of tubes? I dunno...All of my radios have
good enough dynamic range, and none overload...Tube,
or solid state...That doesn't tell me too much...
Only cheaper radios have poor dynamic range, and
overload...:/
But, we ain't talking about R-390's. We are talking
about tubes themselves vs solid state..
I'm still waiting to hear why the use of tubes
didn't help some radios to avoid being pieces of junk...
If tubes themselves are so great, *all* tube radios
should be about on the level of a R-390. But they ain't...
Not by a long shot. The old collins/R390's, etc, etc,
and the collins A and S amateur line, and the older 4 line
drakes are about the only tube radios that I still consider
worth using. All the rest are basically junk, for
my needs. I'm sure this will attract flames 0-plenty,
but I'm picky. I demand *very* good stability.
The collins and drakes basically used the same type
of circuitry. A collins or drake is just as stable
at 30 mc as it is at 3 mc. And the readout scale is
the same also..You can't say that for many other
old tube rigs. I can think of a few that are best
used as doorstops...Unstable at higher freq's,
and drifty as a Chicago snowstorm.
Both my kenwood and icoms can be turned on dead cold,
and never need to be retuned to clarify a SSB signal.
Ever. I can sit on freq for weeks at a time,
and never have to touch up my tuning..."Sure, they
may microdrift with temp changes, but it's never enough
to notice by ear" Most tube rigs can't do that.
I know my drakes can't. They can come close, but after
about a day, you will usually need to touch up the
tuning a tad. I don't know how a R-390 fares
in this regard, but if it's *rock* stable, it's the tube
exception to the rule. And if it is, it's probably cuz
it has a xtal oven, etc...Not cuz it uses tubes...
I won't mention that most of my tube gear needed annual
alignment tweaks and tube checks/changes to keep 100%
up to par.
My solid state rigs never change...Don't have to be fussed
with every few months, if you leave them on all the time
like I did/do. I still like tube radios, and still have a few,
but I'm not blind to reality...There are not many tube radios
that are up to R-390 standards. Tubes look warm, and may add
slightly to the BTU rating of the heating system in the
winter, but they ain't the magic answer to SW-MW nirvana...
Heck, I hardly use mine anymore..Overall, I find them inferior
for *everyday* use. IE: readout resolution, stability, tuning
rates, memories, heck , I could go for days...
The R-390 is a great radio, but not all tube radios can
claim to be R-390's.....Quite possibly none can. The collins
and drake ham radios are fairly close though. But neither of
those were cheap radios when they were built either.
MK

I think you answered your own questions, several times over.

FYI, a well maintained aligned R390A in a stable environment can be
tuned within 300 Hz of a target frequency and will drift less than
half that figure over 24 hours.

There ain't a $10 transistor made with the dynamic range of a tube
designed for small signal RF amplification.