Converting AM Car Radio to Shortwave
 

All right, I think I might have found the proper place to ask about
this. Back in the 90's when GEnie was still around, they had plans to
convert old AM car radios to shortwave receivers. My old Franklin ACE
500 computer wasn't capable of interpreting the file at the time, so I
didn't get to download it. I'm hoping someone here might know where I
could get the instructions.

I know, I could just get off my lazy ass, get an ARRL manual and figure
it out for myself, but if there's an easier option, I'd like to go for
it. All I'm looking for is something that will pick up broadcasts
between upper AM and the scanner frequencies.

By the way, my hotmail account isn't working, so emailing me won't do
any good. Please post where I can find what I'm looking for here.
Thanks.


Ralph Glatt

Converting AM Car Radio to Shortwave
 

julian814 wrote:
All right, I think I might have found the proper place to ask about
this. Back in the 90's when GEnie was still around, they had plans to
convert old AM car radios to shortwave receivers. My old Franklin ACE
500 computer wasn't capable of interpreting the file at the time, so I
didn't get to download it. I'm hoping someone here might know where I
could get the instructions.
Ralph Glatt

Andy writes:
In my opinion, the easiest, most non-destructive way to do this
is to add a converter, using the AM radio as a tuneable IF for
AM transmissions.
A two transistor converter, using a xtal oscillator and a mixer,
can easily do this. Just select the xtal frequency to be about
1000 Khz above or below the middle of the shortwave band you
want.
I am assuming you are only interested in AM shortwave
broadcasts. Any of the other modes would require modification to
the inside of the AM radio....

Anyway, the neat thing about this approach is that no modification
needs to be done to the innards of the AM radio......And you can
still listen to Rush Limbaugh by switching off the converter....

If, on the other hand, you want to modify the AM radio to short
wave without adding anything significant, it depends entirely on
the circuit. In general, you will rewind a bunch of coils, which
means you need equipment for testing and measuring. There are
some AM radio designs that are such that success is extremely
unlikely while others are fairly straightforward ---- it's like asking
"how much does a rock weigh?"
I encourage the CONVERTER approach.... Good luck with your
project. These weekenders can be a lot of fun and very
educational...

Andy W4OAH in Eureka, Texas

Converting AM Car Radio to Shortwave
 

AndyS wrote:
In my opinion, the easiest, most non-destructive way to do this
is to add a converter, using the AM radio as a tuneable IF for
AM transmissions.
A two transistor converter, using a xtal oscillator and a mixer,
can easily do this. Just select the xtal frequency to be about
1000 Khz above or below the middle of the shortwave band you
want.
I am assuming you are only interested in AM shortwave
broadcasts. Any of the other modes would require modification to
the inside of the AM radio....

Anyway, the neat thing about this approach is that no modification
needs to be done to the innards of the AM radio......And you can
still listen to Rush Limbaugh by switching off the converter....

If, on the other hand, you want to modify the AM radio to short
wave without adding anything significant, it depends entirely on
the circuit. In general, you will rewind a bunch of coils, which
means you need equipment for testing and measuring. There are
some AM radio designs that are such that success is extremely
unlikely while others are fairly straightforward ---- it's like asking
"how much does a rock weigh?"
I encourage the CONVERTER approach.... Good luck with your
project. These weekenders can be a lot of fun and very
educational...

Andy W4OAH in Eureka, Texas

Thanks, Andy. I think I've managed to find something a little better
than what I had in mind, anyway - Lindsay books sells a series of books
called the Impoverished Radio Experimenter. I've ordered two of them
that seem likely to have the information I need. My only concern now is
being able to run a tube receiver off of battery power, but I'm hoping
I can figure out something on my own.


Ralph Glatt

Converting AM Car Radio to Shortwave
 

"AndyS" wrote in 1165840350.029509.309650@
79g2000cws.googlegroups.com:

In my opinion, the easiest, most non-destructive way to do this
is to add a converter, using the AM radio as a tuneable IF for
AM transmissions.

Agreed.

And you can still listen to Rush Limbaugh by switching off the
converter....

Or when you switch it on...

http://www.techlib.com/files/rushconv.pdf

Pick your 1MHz band, and tune away. You'll need to tweek a bit if
you want to be very far from 15 MHz.

--
David Hatch
KR7DH

Converting AM Car Radio to Shortwave
 

David wrote:
http://www.techlib.com/files/rushconv.pdf

Pick your 1MHz band, and tune away. You'll need to tweek a bit if
you want to be very far from 15 MHz.

--
David Hatch
KR7DH

Andy comments:

Excellent, David !!! Thanks for the circuit. Note that it can
easily be modified to get WWV also...... I suspect one could
use a CA3028 if one wanted to build it with a single IC, for some
reason...

Yet another simple converter can be made using a NE602.
I don't have a circuit handy, but it can easily be designed from the
data sheet.
Andy W4OAH

PS I'm going to check out 15.42 Mhz --- I hadn't messed with it
before.....

Converting AM Car Radio to Shortwave
 

David ) writes:

Pick your 1MHz band, and tune away. You'll need to tweek a bit if
you want to be very far from 15 MHz.


If you choose the 31 and 25 metre bands you can receive both with one
crystal in the oscillator. Many years ago I built a simple converter
using a 10.7 MHz crystal and a tunable front end so I could tune 31 m band
(osc on the high side) and the 25 m band (osc on the low side). Don't
remember now where I got the circuit but it worked very well with a
standard (in those days!) car radio antenna.

.... Martin VE3OAT

Converting AM Car Radio to Shortwave
 

julian814 wrote:
AndyS wrote:


Andy W4OAH in Eureka, Texas

Thanks, Andy. I think I've managed to find something a little better
than what I had in mind, anyway - Lindsay books sells a series of books
called the Impoverished Radio Experimenter. I've ordered two of them
that seem likely to have the information I need. My only concern now is
being able to run a tube receiver off of battery power, but I'm hoping
I can figure out something on my own.


Ralph Glatt

TUBES!! Tubes? Off of Battery, 6 Volt?, Vibrator? Inverter? 12 Volt B+
tubes ? Not since the 1950s ?
Am I reading too much between the lines ?

Yukio YANO, VE5YS

Except for the audio output stage, we can now run a radio on the power
used to to light the Dial on a Tubes Era Radio !

Converting AM Car Radio to Shortwave
 

Yukio YANO wrote:
TUBES!! Tubes? Off of Battery, 6 Volt?, Vibrator? Inverter? 12 Volt B+
tubes ? Not since the 1950s ?
Am I reading too much between the lines ?

Yukio YANO, VE5YS

Except for the audio output stage, we can now run a radio on the power
used to to light the Dial on a Tubes Era Radio !

Andy writes:
Well, perhaps the OP is a "retro" hobbyist. I have met a few,
especially
youngsters who weren't born till after the ua709 was developed. Sort
of a
historical fascination.... Personally, I have had the hell shocked out
of me
enough to appreciate the privilege of using 14 volts or less (grin)...

Around here, you can usually pick up a transistorized car radio
for
about a dollar at garage sales and resale barns. I have yet to buy one

that didn't work. If you come to Eureka, Texas, I'll give you one for
free......

Andy W4OAH in Eureka, Texas


( If you've ever taken a beer to a job interview, you might live
in Eureka, Texas )

Converting AM Car Radio to Shortwave
 

Yukio YANO wrote:
TUBES!! Tubes? Off of Battery, 6 Volt?, Vibrator? Inverter? 12 Volt B+
tubes ? Not since the 1950s ?
Am I reading too much between the lines ?

Yes, tubes. I have some that were pulled from circa 1960's television
sets, and I thought I'd use them, hoping that they'd be EMP resistant.
Been on kind of a survivalist kick, lately. Doesn't mean I'd be opposed
to using more modern equipment, though. One thing I saw that I liked in
one of the books I purchased was a loop antenna that uses transistors
to amplify the signal. Thought it might be easier than stringing up a
lot of wire. ;-)


Ralph Glatt

Converting AM Car Radio to Shortwave
 

David wrote:
"AndyS" wrote in 1165840350.029509.309650@
79g2000cws.googlegroups.com:

In my opinion, the easiest, most non-destructive way to do this
is to add a converter, using the AM radio as a tuneable IF for
AM transmissions.

Agreed.

And you can still listen to Rush Limbaugh by switching off the
converter....

Or when you switch it on...

http://www.techlib.com/files/rushconv.pdf

Pick your 1MHz band, and tune away. You'll need to tweek a bit if
you want to be very far from 15 MHz.

I'm not that terribly fond of Rush, but I think I might be able to
adapt this to tune in other frequencies, so it should come in handy.
Thanks!


Ralph Glatt