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Old March 18th 14, 05:39 PM posted to rec.radio.shortwave
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Default FM radio reception at ~24MHz?

dave wrote:

Now you get to experience the joy of building a crude preselector. A 20
dB pad might work, try that first.


A friend of mine made one with a coax stub, and a T connecter. I'll ask him
the length and type of coax.

Geoff.

--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379


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Old March 18th 14, 06:00 PM posted to rec.radio.shortwave
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Default FM radio reception at ~24MHz?

On Tue, 18 Mar 2014, Geoffrey S. Mendelson wrote:

dave wrote:

Now you get to experience the joy of building a crude preselector. A 20
dB pad might work, try that first.


A friend of mine made one with a coax stub, and a T connecter. I'll ask him
the length and type of coax.

Wouldn't that have been a notch filter, to get rid of a particularly
strong and pesky specific signal?

If it's just one station, then it is a solution, set and forget. But if
there are multiple stations causing problems, then more is needed.

I was going to say in the old days endless preselectors and tuners and
preamps were built (and even sold as commercial products) in an attempt to
boost the performance of a lot of those low end receivers. I remember one
mod for the Hallicrafters S38 that was just one tube, no tuned circuits,
the performance boosted because the tube meant the existing tuned circuit
wasn't loaded down.

There'd be low pass filters to get rid of FM and TV stations, high pass
filters to get rid of AM broadcast stations, and just things to peak up
specific frequencies to get rid of images.

I don't think any of that would have helped my Hallicrafters S-120A (the
transistor model), that thing didn't need an antenna to receive endless
local broadcast stations. It would have needed a lot of work with
shielding to make a filter between the antenna and receiver useful, it wsa
just picking up the signals directly.

Sometimes it is a too strong local signal, sometimes it is a badly
designed receiver that will never be fixable.

Michael


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Old March 18th 14, 11:23 PM posted to rec.radio.shortwave
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Default FM radio reception at ~24MHz?

On Tue, 18 Mar 2014 14:00:53 -0400, Michael Black wrote:


I don't think any of that would have helped my Hallicrafters S-120A (the
transistor model), that thing didn't need an antenna to receive endless
local broadcast stations. It would have needed a lot of work with
shielding to make a filter between the antenna and receiver useful, it
wsa just picking up the signals directly.


That was my first receiver, my Mother got it from Sears for about $70.
That model was terrible, it looked cool, but it was a real dog. I
finally got an older Hallicrafters, SX-40 I think, and it was much better.
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Old March 19th 14, 02:36 AM posted to rec.radio.shortwave
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Default FM radio reception at ~24MHz?

On Tue, 18 Mar 2014, sctvguy1 wrote:

On Tue, 18 Mar 2014 14:00:53 -0400, Michael Black wrote:


I don't think any of that would have helped my Hallicrafters S-120A (the
transistor model), that thing didn't need an antenna to receive endless
local broadcast stations. It would have needed a lot of work with
shielding to make a filter between the antenna and receiver useful, it
wsa just picking up the signals directly.


That was my first receiver, my Mother got it from Sears for about $70.
That model was terrible, it looked cool, but it was a real dog. I
finally got an older Hallicrafters, SX-40 I think, and it was much better.

I emptied out my bank account of accumulated birthday and Christmas money,
and some other money was added. It was more like $90 Canadian, which was
a lot for me at the time, but the cheapest receiver I could get locally,
and probably the cheapest I could get generally.

How many people were suckered in by those low end receivers? We had no
experience, and as you say, it all looked so good. The dial was awful,
but hey, it had all those places around the world stencilled, I could get
Antarctica if I tuned to that spot there. I was still a beginner, so how
would I know about seeking out a local ham club to see if I could at least
find the same level of receiver for less money on the used market? It
didn't even take that many months for me to get up to speed, but I spent
the money then, rather than waiting.

I was lucky, a year later when I got my ham license, someone lent me (for
a decade) a Hammarlund SP-600, which wasn't perfect, but it was almost
infinitely better than that S-120A. I probably could have kept the Super
Pro, but at one point when I wasn't using it much, he asked if he could
take it back to lend to someone else.

A couple of years ago, a 1950s Hallicrafter ad was making the rounds on
the internet, and that reminded me that Hallicrafter did seem to play up
that aspect, the foreign countries, and the exotic world out there.
Hallicrafters sold a record for some time as part of their advertising,
only 25cents. WHen I remembered seeing those records in their ads, I did
a search, and it's online, though I don't have a specific URL. I was 11
years old when I got that S-120A, all that exotic stuff and exotic
countries I could hear with it was part of Hallicrafter's promotion, and
certainly was a lure to me, when the reality was, those low end receivers
werne't likely to get much more than the strongest of foreign
broadcasters.

At the same time, that past is gone. I think I'd rather have the
illusion of it, the hope that it could happen, than being older and the
world a lot smaller, and that exotic world completely gone.

Michael

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Old March 19th 14, 04:57 AM posted to rec.radio.shortwave
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Default FM radio reception at ~24MHz?

On 03/18/2014 05:39 AM, Joe from Kokomo wrote:

A great tutorial / construction article on how to use the dongle as a DC
to daylight software defined radio (SDR):

QST magazine, January 2013, pp 30-35.

If you know a member of the ARRL, they can print a copy of this article.


Interesting article, thanks for posting that, Joe.

Jon



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Old March 19th 14, 12:34 PM posted to rec.radio.shortwave
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Default FM radio reception at ~24MHz?

On 03/18/2014 11:00 AM, Michael Black wrote:
On Tue, 18 Mar 2014, Geoffrey S. Mendelson wrote:

dave wrote:

Now you get to experience the joy of building a crude preselector. A 20
dB pad might work, try that first.


A friend of mine made one with a coax stub, and a T connecter. I'll
ask him
the length and type of coax.

Wouldn't that have been a notch filter, to get rid of a particularly
strong and pesky specific signal?

If it's just one station, then it is a solution, set and forget. But if
there are multiple stations causing problems, then more is needed.

I was going to say in the old days endless preselectors and tuners and
preamps were built (and even sold as commercial products) in an attempt
to boost the performance of a lot of those low end receivers. I
remember one mod for the Hallicrafters S38 that was just one tube, no
tuned circuits, the performance boosted because the tube meant the
existing tuned circuit wasn't loaded down.

There'd be low pass filters to get rid of FM and TV stations, high pass
filters to get rid of AM broadcast stations, and just things to peak up
specific frequencies to get rid of images.

I don't think any of that would have helped my Hallicrafters S-120A (the
transistor model), that thing didn't need an antenna to receive endless
local broadcast stations. It would have needed a lot of work with
shielding to make a filter between the antenna and receiver useful, it
wsa just picking up the signals directly.

Sometimes it is a too strong local signal, sometimes it is a badly
designed receiver that will never be fixable.

Michael


The MFJ-956 passive pre-selector is in my tool kit. They also make
several actives. They all cover HF, which includes 24 MHz.


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Old March 19th 14, 02:19 PM posted to rec.radio.shortwave
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Default FM radio reception at ~24MHz?

dave wrote:

The MFJ-956 passive pre-selector is in my tool kit. They also make
several actives. They all cover HF, which includes 24 MHz.


In the opposite direction, you can google or search on eBay for an FM TRAP.

Geoff.


--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379

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Old March 19th 14, 05:57 PM posted to rec.radio.shortwave
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Default FM radio reception at ~24MHz?

On 03/19/2014 07:19 AM, Geoffrey S. Mendelson wrote:
dave wrote:

The MFJ-956 passive pre-selector is in my tool kit. They also make
several actives. They all cover HF, which includes 24 MHz.


In the opposite direction, you can google or search on eBay for an FM TRAP.

Geoff.



I probably have a bunch somewhere from my UHF TV years. I'm on the back
side of Mt. Wilson and RF levels are weak enough that I can get away
with scanner antennas and everything. I'd try the Pads first; get the
dingus into its linear operation range.
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Old March 19th 14, 07:49 PM posted to rec.radio.shortwave
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Default FM radio reception at ~24MHz?

On Tue, 18 Mar 2014 22:36:00 -0400, Michael Black wrote:

snip
At the same time, that past is gone. I think I'd rather have the
illusion of it, the hope that it could happen, than being older and the
world a lot smaller, and that exotic world completely gone.

Michael


You are so right, Michael. The illusion, the sitting up all night on
Friday and Saturday night, with headphones on, being about 12-17 years
old, hoping for that illusive foreign station, the dial light glowing, my
pencil and pad waiting for something to copy and to send off for a QSL!
Now, my wireless radio will pick up all the stations I want, all over the
world, just like a local.
I still have my restored Lafayette SWL receiver, a big brother look a
like of the S-38. I turn it on every once in a while, hook up a wire
antenna, and relive the past. There is not much there anymore, but still
can MW DX a lot! Here in Texas, it will pick up both coasts pretty
well. I had an old ham repairman wire it to accept a Heathkit Q-
Multiplier that I also have. With that, and the bandspread, and the IF/
RF amplifier, it works very well!
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Old March 19th 14, 08:39 PM posted to rec.radio.shortwave
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Default FM radio reception at ~24MHz?

sctvguy1 wrote:
You are so right, Michael. The illusion, the sitting up all night on
Friday and Saturday night, with headphones on, being about 12-17 years
old, hoping for that illusive foreign station, the dial light glowing, my
pencil and pad waiting for something to copy and to send off for a QSL!
Now, my wireless radio will pick up all the stations I want, all over the
world, just like a local.


I remember that well too. When I was a teenager someone had a Normande
(probably spelled wrong) AM/FM/Shortwave radio they dropped and it broke
in half. I was able to get it working, and using various things such as my
bed frame, the telephone line, etc, I was able to receive SW signals in a
"garden" (basement) apartment.

Before that I had something, but I don't remember what, maybe a 5 or 6
tube "all american special" with some SW coverage.

I used that until around the time I turned 18, and was given an S-38B.

Unfortuantely I gave that away in my 30's when I started buying "real"
shortwave radios.

I bought one of the first ICF-2010's in the US, brought in a few months
early from Japan. When I got married in 1989, my wife had one too, and
we kept hers, being a few years newer.

My current shortwave radio is a Drake SPR-4, although I have a TR-7
"in the works".

I still have my restored Lafayette SWL receiver, a big brother look a
like of the S-38. I turn it on every once in a while, hook up a wire
antenna, and relive the past. There is not much there anymore, but still
can MW DX a lot! Here in Texas, it will pick up both coasts pretty
well. I had an old ham repairman wire it to accept a Heathkit Q-
Multiplier that I also have. With that, and the bandspread, and the IF/
RF amplifier, it works very well!


I sure miss mine. MW DXing here is worthless because of the high noise.
Although in a previous apartment I was on the edge of a nature preserve,
and with a sheilded MW loop on the fence and the SPR-4, was able to receive
the BBC station on 648kHz, about 3,000 miles away.

Geoff.



--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379



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