"Richard" wrote in message
...
http://www.home.earthlink.net/%7Esrw...rundig-100.htm


Holy Moly!! Two images on a single conversion radio!!!

I'd ask Major Armstrong what's happening here, but he checked out before
I checked in and my old pal, Fred Terman, has been quite silent over the
last couple of decades, or so.

Is there a mathmetical formula for this image frequency stuff?

Please tell me how this happens, oh wise one!


"By now, we had also acquired a Grundig FR-200 "crank" radio, which has
the typical problems of other single-conversion Grundigs we've tested,
such as the Model 350: noticeable and very irritating images on the
broadcast and SW bands, 910 kHz above or below the proper station
frequency. This means, for example, no less than THREE instances of
"WWV, 10 MHz": one below, one on, and one above the correct frequency.
And stations that are very strong cause hetrodynes when their images
land right on top of one you want to tune in."

Frank "Trailer Park" Dresser

This is a common problem with single conversion. If your front end is
too sensitive as on some Grundigs, you can overload the IF and get a
mixing product generated at 2 x IF frequency (455kHz) = 910 kHz. This
gives you the image at 910kHz above and below the actual frequency.
This is why more expensive radios are dual and triple conversion.

Jim

On Wed, 31 Dec 2003 19:38:56 GMT, "Frank Dresser"
wrote:


"Richard" wrote in message
...
http://www.home.earthlink.net/%7Esrw...rundig-100.htm


Holy Moly!! Two images on a single conversion radio!!!

I'd ask Major Armstrong what's happening here, but he checked out before
I checked in and my old pal, Fred Terman, has been quite silent over the
last couple of decades, or so.

Is there a mathmetical formula for this image frequency stuff?

Please tell me how this happens, oh wise one!


"By now, we had also acquired a Grundig FR-200 "crank" radio, which has
the typical problems of other single-conversion Grundigs we've tested,
such as the Model 350: noticeable and very irritating images on the
broadcast and SW bands, 910 kHz above or below the proper station
frequency. This means, for example, no less than THREE instances of
"WWV, 10 MHz": one below, one on, and one above the correct frequency.
And stations that are very strong cause hetrodynes when their images
land right on top of one you want to tune in."

Frank "Trailer Park" Dresser

"R.F. Collins" wrote in message
...
This is a common problem with single conversion. If your front end is
too sensitive as on some Grundigs, you can overload the IF and get a
mixing product generated at 2 x IF frequency (455kHz) = 910 kHz. This
gives you the image at 910kHz above and below the actual frequency.
This is why more expensive radios are dual and triple conversion.

Jim



Images have nothing to do with overloading.

I read the linked web page and it says:

"Earlier in the year 2003, we made the mistake of taking seriously some
very enthusiastic posts on rec.radio.shortwave -- "the trailer-park
shortwave newsgroup" according to one of our acquaintances -- by
dim-wits who were overjoyed with a ten-dollar multiband radio with the
unexpected brand name "Bell & Howell""

"dim-wits"? "the trailer-park shortwave newsgroup" ?

As far as images go, there's only one. The signal mixes with the local
oscillator. Either the sum or difference signal is the desired signal.
The other signal is the image.

There may be other false signals from oscillator harmonics. But these
will be totally out of band, even VHF signals.

The page's insults and cheap shots on cheap radios continue:

http://www.home.earthlink.net/~srw-s...rundig-100.htm

It's just one crackpot's opinion, but I find insult humor unimaginative.

There's is a another image at the bottom of the page:

"by Steve Waldee, retired broadcast consultant, AM-FM transmitter
engineer, and audio specialist;"

If the original poster is still reading this, I'll suggest the problem
with FM DXing has little to do with PLLs and more to do with stereo. It
takes a lot more signal to get adaquate quieting with FM stereo.

I used to receive a Green Bay public radio station from Chicago with a
DX-440 on a semiregular basis. No more, the local stations around 88 -
89 Mhz are broadcasting almost full time now.

All the radios on the webpage, aside from the old Grundig, were bottom
end in both price and performance. There might be a pattern there.

Frank "trailer park" Dresser

"Frank Dresser" wrote in message

I read the linked web page and it says:

"Earlier in the year 2003, we made the mistake of taking seriously some
very enthusiastic posts on rec.radio.shortwave -- "the trailer-park
shortwave newsgroup" according to one of our acquaintances -- by
dim-wits who were overjoyed with a ten-dollar multiband radio with the
unexpected brand name "Bell & Howell""

"dim-wits"? "the trailer-park shortwave newsgroup" ?

Who is the *real* dimwit here? You would have to be the original
dimwit to really expect a $10 radio to actually be very useful. Good
grief...I've never seen one, even the picture, and I know it sucks
just from the description. They DO NOT build good shortwave radios and
sell them for $10. I have to good sense not to believe
otherwise...Mamma didn't raise no "trailer park" fool.




The page's insults and cheap shots on cheap radios continue:

"clipped from that site"...
If someone posts an enthusiastic comment about one particular brand of
sw radio or scanner, this is immediately "rebutted" (allegedly) by
those who disagree. This is, as I state in my Icom articles, a futile
act. Everyone is entitled to the enjoyment of the hobby and to
appreciate his or her own radio. By telling an enthusiast that his
"radio is bad" or that his or her taste is faulty, nothing positive is
accomplished....

OK, let me get this right...He's complaining because no one would say
the B@H was a piece of dime store junk, but now he's complaining
because some might or did in other cases with other brand
radios...Hell, I think most all portables are basically junk. I've
never seen one that was really worth a hoot for anything serious. I
wouldn't buy any of them. That's my opinion, and I'm sticking to it. I
don't care if I'm chased out of this house, and forced to a trailer
park to live next door to the guy that wrote that web page. Normally,
I never comment on specific radios, unless it's a question on own I
actually own. I realize not all people need radios that cost several
hundred dollars or more to listen to VOA or whatever. I don't normally
comment on other peoples radios, unless they start developing
incorrect delusions regarding some aspect of it's performance, and
even that is rare. I know the B@H would be useless to me, but there is
no point on raining on someone elses parade just to act radio
snobbish. That's why I never add to threads like that. If the poster
likes the thing, more power to him. He's certainly a lot less lighter
in the pocket than I am with my various models. MK