David Toepfer ) writes:

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

It was before my time, but I don't think anyone used linears much
for AM. Yes, it could be done, but I don't think it was done much.

What they'd do is take the exciter, and put it in CW mode (maybe pulling
the modulator tubes to decrease current drain and strain on the power
supply) and feed it into a high level stage that was plate modulated.
And of course, there was a really hefty plate modulator to go with it.

Michael VE2BVW

In article ,
(David Toepfer) writes:

Hallicrafters SX-28
is the receiver to have if you are looking for good sound.

Lots of good LOUD sound, and plenty of bass, which is great for AM-BC and SWL,
but not for Ham work. Make sure you get a 28 that's been thoroughly rebuilt,
or set aside LOTs of time and eyesight to do the job right.

People say it has good frequency stability.

For 160m thru 40m AM you don't need much stability, and anyway you'll be
constantly tweaking the tuning to dodge the QRM and maximize voice quality --
and besides, you have to have *something* to twiddle while sitting there
listening, right?

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
Hard to beat in any sense. The non-A sounds a bit better, with its L-C IF
filtering rather than the A's mech filters. However, while the non-A's audio
is adequate, there's a clean mod to put push-pull audio in the 390-A. I have
it, and it sounds awesome. Of course, you can feed the non-A's output to an
outboard audio amp.

Collins 51J-4
Or the J-3 (R388). Mine sounds very good on AM, plenty of audio. BW is pretty
wide, good for hi-fi AM; 1st xtal filter position on the J-3 is good with
QRM/N.

Collins 75A-4
I had one, and somehow the audio left me less than impressed. A superb SSB/CW
rx, but even there the audio was not crisp. Yes, I had all three filters.
Some else said the A4 was not a good AM rx, period. I wouldn't go that far --
there are mods for the audio. You might look for an A-3, since you won't need
that great passband tuning for AM, and $$ you save will buy more TX.

This is the only Ham-band-only rx you listed. If I were to own just one BA rx
with good audio, I sure as heck would get a general-coverage set.

Hammarlund SP-600
Another hard-to-beat classic. Good single-ended audio. Freq readout isn't
nearly as good as on the linear-tuning radios -- about like on the SX-28.
Front end can overload and give spurious responses, at least on the BC band.
But with its 8 and 13 KC bandwidth settings, the SP-600 can't be beat for hi-fi
reception of AM from the Hams who are frustrated BC engineers and don't cut off
their mikes at 3 KC. For that bandwidth, you'll want the SP-600 (or 400, what
the heck), or the R390.

Also consider some version of the Racal RA-17 with the 1 Watt audio feature and
8 KC BW setting. Whatever you get, enjoy -- 73, Mike K. AA1UK





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

David Toepfer ) writes:

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

It was before my time, but I don't think anyone used linears much
for AM. Yes, it could be done, but I don't think it was done much.

What they'd do is take the exciter, and put it in CW mode (maybe pulling
the modulator tubes to decrease current drain and strain on the power
supply) and feed it into a high level stage that was plate modulated.
And of course, there was a really hefty plate modulator to go with it.

Michael VE2BVW

I like and use Valiant I's. I have 2 of them and they sounds quite nice,
via the ER audio mods. One can have a Valiant for the same price as asked
for a Ranger. Rangers are horribly overrated! The extra 100 watts out of
the Valiant helps, too!! The DX-100 is a nice classic rig, if found in
suitable condition (read: wiring condition and corrosion). The VF-1
design VFO in the DX-100 may be quite problematic, too. But, they do
sound good, don't they?
Receiver wise? Yes, the SX-28 sounds nice but conditions require better
spectrum control. I use either a 75A4 or a National NC-303. Heck, an
SX-100 is quite fine, too. Or how about an HQ-170AC? Not general
coverage.. but can be had for a song and really work fine! But, like
Ford's and Chevy's, what we have here is what you like, personally..
de K3HVG

On Sun, 26 Oct 2003 06:22:09 -0500, K3HVG sent into
the ether:

I like and use Valiant I's. I have 2 of them and they sounds quite nice,
via the ER audio mods. One can have a Valiant for the same price as asked
for a Ranger. Rangers are horribly overrated! The extra 100 watts out of
the Valiant helps, too!! The DX-100 is a nice classic rig, if found in
suitable condition (read: wiring condition and corrosion). The VF-1
design VFO in the DX-100 may be quite problematic, too. But, they do
sound good, don't they?
Receiver wise? Yes, the SX-28 sounds nice but conditions require better
spectrum control. I use either a 75A4 or a National NC-303. Heck, an
SX-100 is quite fine, too. Or how about an HQ-170AC? Not general
coverage.. but can be had for a song and really work fine! But, like
Ford's and Chevy's, what we have here is what you like, personally..
de K3HVG



I like my B&W 5100-B. Although it doesn't do topband, it sounds
great, without having to mod the audio. My second choice is my Ranger
with a slight mod to match it to my voice range. It's been so long
since I did the mod I would have to dig out the manual and look at it
for the marked changes. Course the Ranger sound is heard better
through the Johnson Desk :}

Dan
www.outdoorfrontiers.com
REMOVE left x for direct e-mail reply

On Sun, 26 Oct 2003 06:22:09 -0500, K3HVG sent into
the ether:

I like and use Valiant I's. I have 2 of them and they sounds quite nice,
via the ER audio mods. One can have a Valiant for the same price as asked
for a Ranger. Rangers are horribly overrated! The extra 100 watts out of
the Valiant helps, too!! The DX-100 is a nice classic rig, if found in
suitable condition (read: wiring condition and corrosion). The VF-1
design VFO in the DX-100 may be quite problematic, too. But, they do
sound good, don't they?
Receiver wise? Yes, the SX-28 sounds nice but conditions require better
spectrum control. I use either a 75A4 or a National NC-303. Heck, an
SX-100 is quite fine, too. Or how about an HQ-170AC? Not general
coverage.. but can be had for a song and really work fine! But, like
Ford's and Chevy's, what we have here is what you like, personally..
de K3HVG



I like my B&W 5100-B. Although it doesn't do topband, it sounds
great, without having to mod the audio. My second choice is my Ranger
with a slight mod to match it to my voice range. It's been so long
since I did the mod I would have to dig out the manual and look at it
for the marked changes. Course the Ranger sound is heard better
through the Johnson Desk :}

Dan
www.outdoorfrontiers.com
REMOVE left x for direct e-mail reply

I like and use Valiant I's. I have 2 of them and they sounds quite nice,
via the ER audio mods. One can have a Valiant for the same price as asked
for a Ranger. Rangers are horribly overrated! The extra 100 watts out of
the Valiant helps, too!! The DX-100 is a nice classic rig, if found in
suitable condition (read: wiring condition and corrosion). The VF-1
design VFO in the DX-100 may be quite problematic, too. But, they do
sound good, don't they?
Receiver wise? Yes, the SX-28 sounds nice but conditions require better
spectrum control. I use either a 75A4 or a National NC-303. Heck, an
SX-100 is quite fine, too. Or how about an HQ-170AC? Not general
coverage.. but can be had for a song and really work fine! But, like
Ford's and Chevy's, what we have here is what you like, personally..
de K3HVG

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
.

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."

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