"Tony Meloche" wrote in message
...




In many, many applications today where an AM tuner is included (a
low-priced stereo reciever is a good example) the AM circuitry is not
even as good as the better "pocket" transistor radios of the 1960's.
The designer's view is: "Hey, they aren't buying a stereo rceiver to
listen to AM, fercryinoutloud!" - and they save some nickles there. The
difference between a workable AM circuit and a really *good* AM circuit
is the width of the Grand Canyon.

Huh. That's got me wondering if one or more of the suppliers has come up
with a cheap, crummy AM section. Generally, I don't expect most of the
manufacturers to do much design. They like to use as many industry standard
parts as possible. If the crummy AM section becomes the industry standard
part, it will greately drive down the manufacturing volume of the better
part, even if there's only a nickel's difference at the start.

Back in the AA5 days, there was a AA4 which didn't use an IF amplifier tube
or a second IF transformer. They were around, but they were known poor
performers and not very popular.

Another possibility is poor alignment, especially with ceramic filters.
Inexpensive ceramic filters might not fall exactly on their nominal
frequency. I have a Realistic DX-100 like that. I suppose it was factory
aligned at 455 kHz, but the IF had a double peak. I realigned it to the
center frequency of the ceramic filter and the adjacent channel rejection
got much better and the sensitivity went up. Doing a careful alignment
takes a little extra time but the manufacturers hate that sort of thing,
especially on assembly lines.





I noticed Doug Smith's post on the increase in noise and interference.
Those are important points and he's right.


Agreed.




What modern (new or used) AM radio can I buy that can pull in distant
stations?

I have a Realistic DX440, which does a good job. Others have tried and
like
the GE superradio and CC radio. The GE is much less expensive.


SuperRadio III is a very good AMDX machine, but the dial pointer is
certainly not the last word in accuracy. Still, with a good longwire,
or even a select-a-tenna, it gives excellent performance. My AMDX log
from my shack here in SW Michigan is 112 verified stations so far with
the Superadio III, and I'm not done covering the bands from all
directions yet.

Tony

Just have to count those 10kHz steps, especially if you're DXing in the
dark!

Frank Dresser

I have a Realistic DX-100 like that. I suppose it was factory
aligned at 455 kHz, but the IF had a double peak. I realigned it to the
center frequency of the ceramic

************rest snipped****************

You have one of those Frank? You like? LOL. I love mine. I had two and traded
with DXZoner, who used to post in here about a year ago.

It was my first 'I thought' real receiver. I think the definition of your
'first' receiver is the one that peaked your curiousity and then you continued
in the radio hobby.

That's the DX100 for me. Matter of fact, I went in the living room about
fifteen minutes ago and turned it on to let it warm up. It's in mint condition,
got the box and papers for it. Had a tech buddie of mine get in it with his
equipment and he said it was just a tad off. I don't know how much a tad
was/is. But I'll measure it with my DX399 hooked to a yo-yo antenna wire from
Bil'ls company (that antenna has been everywhere and been put through crap) and
match it up to see the exact freq. at it's always dead on.

But it has to be on for about a good 45minutes to be stable. How's the drift on
yours? When does it even out for you on your piece?

~^Monitoring The Spectrum^~
Hammarlund HQ129X /Heathkit Q Multiplier
Hammarlund HQ140X
Multiple GE P-780's(GREAT BCB Radios)
RCA Victor *Strato- World*
RCA Victor RJC77W-K(Walnut Grain)
1942 Zenith Wave Magnet 6G 601M
Cathedral/ Ross#2311/Rhapsody-MultiBand
DX100/394/*SUPER*398/399/402
OMGS Transistor Eight/Realistic 12-1451
Henry Kloss Model One/Bell+Howell
~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
Alpha Delta DX Sloper 57ft.
500ft. 12AWG. (non-terminated)
120ft. 12 AWG Sloper
2 Radio Shack Loop Antennas
Radio Shack Amplified Antenna
30X30 DiamondLoop(six section 830pf Cap)
* Diamond Loop mounted to Lazy Susan TurnTable*
*21/2X2ft.FiveSpoked~Penta-Loop~PancakeLoop*

"GO BEARCATS" wrote in message
...

You have one of those Frank? You like? LOL. I love mine. I had two and
traded
with DXZoner, who used to post in here about a year ago.

I've got mixed feelings about it. The sensitivity and selectitivity are OK.
The radio rejects power line noise well. It doesn't use much power, and it
looks like it would be easy to make an external battery pack for it if I
wanted to go portable with it.


The image rejection is poor, especially on the top two bands. The stability
is OK for AM.. None of the problems are unexpected on an unexpensive radio.

In my opinion, the radio's real drawback is it's tuning. The tuning has too
much drag and backlash. It feels rubbery. The dial graduations are too
coarse. The fine tuning isn't nearly as useful as a real bandspread.

I've only seen pictures of the DX-200. It does have a sort of family
resembelance to the DX-100. The DX-200 looks to have better dial
graduations and a real bandspread. If the 200 is the 100 with better
tuning, it's probably a pretty good radio.

The DX-100 is a decent radio for AM DXing. I can often hear WLW during the
day here in the Chicago area off the internal ferrite antenna. The radio's
weaknesses get more troublesome on the higher bands.



It was my first 'I thought' real receiver. I think the definition of your
'first' receiver is the one that peaked your curiousity and then you
continued
in the radio hobby.

That's the DX100 for me. Matter of fact, I went in the living room about
fifteen minutes ago and turned it on to let it warm up. It's in mint
condition,
got the box and papers for it. Had a tech buddie of mine get in it with
his
equipment and he said it was just a tad off. I don't know how much a tad
was/is. But I'll measure it with my DX399 hooked to a yo-yo antenna wire
from
Bil'ls company (that antenna has been everywhere and been put through
crap) and
match it up to see the exact freq. at it's always dead on.

But it has to be on for about a good 45minutes to be stable. How's the
drift on
yours? When does it even out for you on your piece?


Maybe fifteen minutes to half an hour and there's no noticable drift on AM.
It never stabilizes enough to be "set and forget" on SSB. It will drift
noticably with room temperature changes.

Frank Dresser

My DX-200 is a drifter. Pretty worthless with tinny sound.
It does "look" cool though....



"Frank Dresser" wrote in message
...

"GO BEARCATS" wrote in message
...

You have one of those Frank? You like? LOL. I love mine. I had two and
traded
with DXZoner, who used to post in here about a year ago.

I've got mixed feelings about it. The sensitivity and selectitivity are
OK.
The radio rejects power line noise well. It doesn't use much power, and
it
looks like it would be easy to make an external battery pack for it if I
wanted to go portable with it.


The image rejection is poor, especially on the top two bands. The
stability
is OK for AM.. None of the problems are unexpected on an unexpensive
radio.

In my opinion, the radio's real drawback is it's tuning. The tuning has
too
much drag and backlash. It feels rubbery. The dial graduations are too
coarse. The fine tuning isn't nearly as useful as a real bandspread.

I've only seen pictures of the DX-200. It does have a sort of family
resembelance to the DX-100. The DX-200 looks to have better dial
graduations and a real bandspread. If the 200 is the 100 with better
tuning, it's probably a pretty good radio.

The DX-100 is a decent radio for AM DXing. I can often hear WLW during
the
day here in the Chicago area off the internal ferrite antenna. The
radio's
weaknesses get more troublesome on the higher bands.



It was my first 'I thought' real receiver. I think the definition of
your
'first' receiver is the one that peaked your curiousity and then you
continued
in the radio hobby.

That's the DX100 for me. Matter of fact, I went in the living room about
fifteen minutes ago and turned it on to let it warm up. It's in mint
condition,
got the box and papers for it. Had a tech buddie of mine get in it with
his
equipment and he said it was just a tad off. I don't know how much a tad
was/is. But I'll measure it with my DX399 hooked to a yo-yo antenna wire
from
Bil'ls company (that antenna has been everywhere and been put through
crap) and
match it up to see the exact freq. at it's always dead on.

But it has to be on for about a good 45minutes to be stable. How's the
drift on
yours? When does it even out for you on your piece?


Maybe fifteen minutes to half an hour and there's no noticable drift on
AM.
It never stabilizes enough to be "set and forget" on SSB. It will drift
noticably with room temperature changes.

Frank Dresser

"Jim Hackett" wrote in message
hlink.net...
My DX-200 is a drifter. Pretty worthless with tinny sound.

The appearant drift of my DX-100 was reduced after I aligned it. The
ceramic IF filter didn't peak at exactly 455 kHz. The IF had a dip between
two peaks. I was tuning it in on the bigger of the two peaks, but didn't
take much drift for it to get detuned. I religned the IF cans to the peak
of the ceramic filter, something like 456 kHz. Really very little
difference. But after the relignment, I'm sure the bandpass was more
symmetrical, and a drift of a few hundred Hz didn't produce so much audio
distortion. No doubt the local oscillator was just as drifty as it always
had been, but the tuning was a bit less critical.

If tuning across a strong station seems to give an unsymerical response on
the S-meter, a careful alignment may fix a couple of problems.


It does "look" cool though....




And I'm sure making cool looking radios was a big part of the business plan
of the Hallidrifters Corporation.

Frank Dresser