Mike Andrews wrote:

I throw my lot in with Scott on the R-390/R-390A for stability and
sensitivity. It's all technology that I understand, but it sure is
a lot like magic.

I thought I understood it, then I found a sensitivity problem on the lowest
band... and now I am pretty sure I don't. AAARGH! Time to call Chuck Rippel
again.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Mike Andrews wrote:

I throw my lot in with Scott on the R-390/R-390A for stability and
sensitivity. It's all technology that I understand, but it sure is
a lot like magic.

I thought I understood it, then I found a sensitivity problem on the lowest
band... and now I am pretty sure I don't. AAARGH! Time to call Chuck Rippel
again.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:
wrote:
the SX28 and 28A were designed in the 30s.

I also own both an R390 and an R390A. If you want the ultimate in AM
performance, either of these beauties will do it for you. I perfer
the R390 because it tunes more smoothly and overall has a smoother
feel. On the air performance is similar in both, and of course both
have the famous mechanical dial.

The RF performance on these radios cannot be beat. In my office at work
I have a Watkins-Johnson HF system that cost the government a few tens of
thousands of dollars and directly digitizes the IF for digital filtering
and demodulation. The R-390A is better at pulling weak signals out of
the trash (although the panadaptor display on the Watkins-Johnson is hard to
beat).

The problem with the R390 is that the audio quality just stinks. Great for
DXing, not good for casual shortwave listening. The filters ring like mad
and the distortion on the output stage is way too high for my taste. There
are some aftermarket AF decks for these but they don't solve the real problems.

But, my god, they pull stuff out of nowhere. And once they are warmed up,
they are stable enough to stay tuned on a RTTY station for weeks.

I throw my lot in with Scott on the R-390/R-390A for stability and
sensitivity. It's all technology that I understand, but it sure is
a lot like magic.

I don't have the reservations about fidelity and distortion that
he does: they sound about as good as my Yaesu FRG-100 and my Icom
PCR-1000.

Anyone who wants to give (or lend) me a recent-model WJ receiver is
welcome to do so; I'll happily do A/B comparisons for a year or two.

--
Mike Andrews, once WN5EGO, and hoping to be W5EGO

Tired old sysadmin

In article , (Scott Dorsey)
writes:

The problem with the R390 is that the audio quality just stinks. Great for
DXing, not good for casual shortwave listening. The filters ring like mad
and the distortion on the output stage is way too high for my taste. There
are some aftermarket AF decks for these but they don't solve the real
problems.

Might you have meant the "A" when you said the filters ring? SWLs often prefer
the older non-A since its LC IF selectivity doesn't ring like the mechanical
filters in the "A".

There is the Kleronomous audio module mod for the "A" -- I have it and it
sounds great, though as you said it can't cover up the filter ringing, if that
bothers you.

I don't know of any audio mods for the non-A, but you can always feed the Diode
Load output to the firebottle mono amp (Dyna into Big Advents?) of your choice.
73, Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.

Mike Knudsen wrote:
In article , (Scott Dorsey)
writes:

The problem with the R390 is that the audio quality just stinks. Great for
DXing, not good for casual shortwave listening. The filters ring like mad
and the distortion on the output stage is way too high for my taste. There
are some aftermarket AF decks for these but they don't solve the real
problems.

Might you have meant the "A" when you said the filters ring? SWLs often prefer
the older non-A since its LC IF selectivity doesn't ring like the mechanical
filters in the "A".

Yes, I did. I think the mechanical filters are worth every penny for the
better selectivity. I mean, amazing selectivity. But the ringing gets
to you on long listening sessions.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Mike Knudsen wrote:
In article , (Scott Dorsey)
writes:

The problem with the R390 is that the audio quality just stinks. Great for
DXing, not good for casual shortwave listening. The filters ring like mad
and the distortion on the output stage is way too high for my taste. There
are some aftermarket AF decks for these but they don't solve the real
problems.

Might you have meant the "A" when you said the filters ring? SWLs often prefer
the older non-A since its LC IF selectivity doesn't ring like the mechanical
filters in the "A".

Yes, I did. I think the mechanical filters are worth every penny for the
better selectivity. I mean, amazing selectivity. But the ringing gets
to you on long listening sessions.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

In article , (Scott Dorsey)
writes:

The problem with the R390 is that the audio quality just stinks. Great for
DXing, not good for casual shortwave listening. The filters ring like mad
and the distortion on the output stage is way too high for my taste. There
are some aftermarket AF decks for these but they don't solve the real
problems.

Might you have meant the "A" when you said the filters ring? SWLs often prefer
the older non-A since its LC IF selectivity doesn't ring like the mechanical
filters in the "A".

There is the Kleronomous audio module mod for the "A" -- I have it and it
sounds great, though as you said it can't cover up the filter ringing, if that
bothers you.

I don't know of any audio mods for the non-A, but you can always feed the Diode
Load output to the firebottle mono amp (Dyna into Big Advents?) of your choice.
73, Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.

wrote:
the SX28 and 28A were designed in the 30s.

I also own both an R390 and an R390A. If you want the ultimate in AM
performance, either of these beauties will do it for you. I perfer
the R390 because it tunes more smoothly and overall has a smoother
feel. On the air performance is similar in both, and of course both
have the famous mechanical dial.

The RF performance on these radios cannot be beat. In my office at work
I have a Watkins-Johnson HF system that cost the government a few tens of
thousands of dollars and directly digitizes the IF for digital filtering
and demodulation. The R-390A is better at pulling weak signals out of
the trash (although the panadaptor display on the Watkins-Johnson is hard to
beat).

The problem with the R390 is that the audio quality just stinks. Great for
DXing, not good for casual shortwave listening. The filters ring like mad
and the distortion on the output stage is way too high for my taste. There
are some aftermarket AF decks for these but they don't solve the real problems.

But, my god, they pull stuff out of nowhere. And once they are warmed up,
they are stable enough to stay tuned on a RTTY station for weeks.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Hi,

I own a SX-28A, which is similar to the 28. A fine looking old radio,
somewhat difficult to work on. Stable, but lacking in sens and
selectivity when compared to the other radios you mentioned. Remember
the SX28 and 28A were designed in the 30s.

I also own both an R390 and an R390A. If you want the ultimate in AM
performance, either of these beauties will do it for you. I perfer
the R390 because it tunes more smoothly and overall has a smoother
feel. On the air performance is similar in both, and of course both
have the famous mechanical dial.

I also own a SP-600 JX-17. Very fun radio, smooth tuning, but crowded
dial and not easy to interpolate the received frequency. Fine for
tuning the SW broadcast bands, not so fine for Ham bands.

Regards,

Bob

On 25 Oct 2003 06:33:19 -0700, (David Toepfer)
wrote:

In the future I would like to set up an AM station for the low bands
(just 160m, 80m, and 40m) and am doing some research as to what
equipment I should be looking for. I am looking to choose a good
quality Receiver and Transmitter to start with and stay with. I don't
have the space for a BoatAnchor collention right now, but would like
to set myself up with a station with nice hi-quality audio for AM
work. I am not looking to DX with them or contest with them. Just
looking to do some high quality domestic AM work.

To start I am looking for a good receiver, preferably with really good
fidelity for AM. From what I have been reading everywhere it seems
that the

Hallicrafters SX-28

is the receiver to have if you are looking for good sound. People say
it has good frequency stability. I was wondering how you would
compare it on these points as well as selectivity and sensitivity with
these other receivers which seem to be quite fine as well:

Collins R-390
Collins 51J-4
Collins 75A-4

Hammarlund SP-600

Or does anyone have any others to suggest as well?

Also, I am completely in the dark as far as transmitters go for the
same kind of work. I am likewise looking for good high fidelity witr
good frequency stability AM. But I don't know where to go (or is
building your own rack the best way to go for this kind of work?)

The transmitter I have come across for hi-fidelity AM work seems to be
the

Johnson Ranger and
Johnson Ranger II (not sure what is the difference between them)

Or is the Valiant or Viking better?
But I am sure there are others out there as well.

Any help with suggesting a good kW linear that would preserve a
hi-fidelity signal would be appreciated as well.

Are there any other things I should be considering as well that I have
missed asking because of my relative newness to this area?

This is a long term project and I am just in the information gathering
phases right now.

Any help would be appreciated.

73

dt
.