Hi guys and gals. Pretty new to shortwave and I know its late to be asking
but how many of you use a DX-394 communications receiver and what do you
think about it?
I paid $250 for mine on ebay (prolly too much) with a lot of mods done to it
and got the super Zepp shortwave antwnna. Here are the mods!
1) SWITCHABLE I.F. FILTERS-A switch has been installed to the front panel,
using the Noise blanker switch of the radio that allows listeners to choose
between Wide or Narrow Bandwidths! The two I.F. Filters have been set up on
a switch so that you can listen to the wide AM filter for casual, easy
listening or flip over to a narrow bandwidth for Dxing or for listening to
weak signals on a crowded band! The Bandwidth of the narrow, outboard filter
installed is a tight 3.5-4 KHZ, which is great for SSB and crowded SW band
conditions.

2) The "Chuff Chuff" noise when fine tuning was stopped with a simple mod.

3) Keyboard Beeps mod was done to stop the annoying Beeping.

4) Crosstalk Mod was done by adding components in the ceramic filter
circuit. This greatly reduces the problems from strong adjacent channel
interference or bleed thru from the filters. This narrows the bandwidth by
adding more capacitors to the circuit around Q13 is the second part of this
mod.

5) Weight added to Main tuning dial makes the radio feel like a "Real Radio"
with a heavy flywheel dial. Approximately 4 oz. of lead was added to the
dial and helps the "Feel " of the dial.

6) RF Gain control mod provides better linearity when adjust gain of radio.
This makes it much more flexible when tuning and listening to loud or strong
SW signals. This mod had a big effect on the radio as well!

7) AGC mod done for a slower speed. This makes it easier to listen to on AM
or Sideband. The original manufacturer had a very fast attack AGC speed. Up
and down signals will not pump the audio sound unnatural now. In ham lingo,
the AGC has been modified to compensate for fast QSB.

8) Audio hiss removed from audio circuit by adding more capacitors to filter
out some of the higher audio frequencies. Thus, this gives the audio more
punch and makes it easier to listen to. It also helps make up for the cheap
built in speaker. An external, Good quality speaker is also recommended!

9)Using the frequency counter in my $3000 transceiver the USB and LSB
readouts have been adjusted on the DX-394 to show correct readout with an
internal trimmer capacitor. Typically the frequency readout of the DX-394
shows the center frequency rather than the actual frequency of the SSB
signal.

10)Audio Quality-Additional capacitors have been added to the audio circuit
which give the radio real bass punch and make it sound like a real
communications receiver!

11)Hum Reduction-A 2200 uF capacitor is added to the power supply to reduce
the hum heard with low audio gain commonly used with headphones. With this
mod the hum disappears! Additional voltage regulation has been added to the
power supply circuit to make the entire system more stable!

12) The top and bottom cases of the radio cabinet have been covered on the
inside with conductive, aluminum tape that will reduce interference. RFI
produced from nearby broadcast stations, computers, TV's and computer
monitors is greatly reduced with this new mod. Birdies, spurious signals and
heterodynes caused by these and other electronic devices is shielded out by
this new aluminum tape's shielding.

Please let me know what you THINK!



Thanks for looking

john wrote:

Hi guys and gals. Pretty new to shortwave and I know its late to be asking
but how many of you use a DX-394 communications receiver and what do you
think about it?
I paid $250 for mine on ebay (prolly too much) with a lot of mods done to it
and got the super Zepp shortwave antwnna. Here are the mods!
1) SWITCHABLE I.F. FILTERS-A switch has been installed to the front panel,
using the Noise blanker switch of the radio that allows listeners to choose
between Wide or Narrow Bandwidths! The two I.F. Filters have been set up on
a switch so that you can listen to the wide AM filter for casual, easy
listening or flip over to a narrow bandwidth for Dxing or for listening to
weak signals on a crowded band! The Bandwidth of the narrow, outboard filter
installed is a tight 3.5-4 KHZ, which is great for SSB and crowded SW band
conditions.

2) The "Chuff Chuff" noise when fine tuning was stopped with a simple mod.

3) Keyboard Beeps mod was done to stop the annoying Beeping.

4) Crosstalk Mod was done by adding components in the ceramic filter
circuit. This greatly reduces the problems from strong adjacent channel
interference or bleed thru from the filters. This narrows the bandwidth by
adding more capacitors to the circuit around Q13 is the second part of this
mod.

5) Weight added to Main tuning dial makes the radio feel like a "Real Radio"
with a heavy flywheel dial. Approximately 4 oz. of lead was added to the
dial and helps the "Feel " of the dial.

6) RF Gain control mod provides better linearity when adjust gain of radio.
This makes it much more flexible when tuning and listening to loud or strong
SW signals. This mod had a big effect on the radio as well!

7) AGC mod done for a slower speed. This makes it easier to listen to on AM
or Sideband. The original manufacturer had a very fast attack AGC speed. Up
and down signals will not pump the audio sound unnatural now. In ham lingo,
the AGC has been modified to compensate for fast QSB.

8) Audio hiss removed from audio circuit by adding more capacitors to filter
out some of the higher audio frequencies. Thus, this gives the audio more
punch and makes it easier to listen to. It also helps make up for the cheap
built in speaker. An external, Good quality speaker is also recommended!

9)Using the frequency counter in my $3000 transceiver the USB and LSB
readouts have been adjusted on the DX-394 to show correct readout with an
internal trimmer capacitor. Typically the frequency readout of the DX-394
shows the center frequency rather than the actual frequency of the SSB
signal.

10)Audio Quality-Additional capacitors have been added to the audio circuit
which give the radio real bass punch and make it sound like a real
communications receiver!

11)Hum Reduction-A 2200 uF capacitor is added to the power supply to reduce
the hum heard with low audio gain commonly used with headphones. With this
mod the hum disappears! Additional voltage regulation has been added to the
power supply circuit to make the entire system more stable!

12) The top and bottom cases of the radio cabinet have been covered on the
inside with conductive, aluminum tape that will reduce interference. RFI
produced from nearby broadcast stations, computers, TV's and computer
monitors is greatly reduced with this new mod. Birdies, spurious signals and
heterodynes caused by these and other electronic devices is shielded out by
this new aluminum tape's shielding.

Please let me know what you THINK!

Thanks for looking

Sounds like you did some nice mod's to your '394'. Are the details for
all of them available on the Net?


-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

I like my DX 394 even without mods, and I have not had any done S. I
suppose modifying is cheaper than spending $1000 or more for a radio S. I
think you will like it. Now, if you have a good antenna and the receiver is
grounded you should be all set to listen. Hopefully the ionosphere will
cooperate for you g.
V
"starman" wrote in message
...
john wrote:

Hi guys and gals. Pretty new to shortwave and I know its late to be
asking
but how many of you use a DX-394 communications receiver and what do you
think about it?
I paid $250 for mine on ebay (prolly too much) with a lot of mods done
to it
and got the super Zepp shortwave antwnna. Here are the mods!
1) SWITCHABLE I.F. FILTERS-A switch has been installed to the front
panel,
using the Noise blanker switch of the radio that allows listeners to
choose
between Wide or Narrow Bandwidths! The two I.F. Filters have been set up
on
a switch so that you can listen to the wide AM filter for casual, easy
listening or flip over to a narrow bandwidth for Dxing or for listening
to
weak signals on a crowded band! The Bandwidth of the narrow, outboard
filter
installed is a tight 3.5-4 KHZ, which is great for SSB and crowded SW
band
conditions.

2) The "Chuff Chuff" noise when fine tuning was stopped with a simple
mod.

3) Keyboard Beeps mod was done to stop the annoying Beeping.

4) Crosstalk Mod was done by adding components in the ceramic filter
circuit. This greatly reduces the problems from strong adjacent channel
interference or bleed thru from the filters. This narrows the bandwidth
by
adding more capacitors to the circuit around Q13 is the second part of
this
mod.

5) Weight added to Main tuning dial makes the radio feel like a "Real
Radio"
with a heavy flywheel dial. Approximately 4 oz. of lead was added to the
dial and helps the "Feel " of the dial.

6) RF Gain control mod provides better linearity when adjust gain of
radio.
This makes it much more flexible when tuning and listening to loud or
strong
SW signals. This mod had a big effect on the radio as well!

7) AGC mod done for a slower speed. This makes it easier to listen to on
AM
or Sideband. The original manufacturer had a very fast attack AGC speed.
Up
and down signals will not pump the audio sound unnatural now. In ham
lingo,
the AGC has been modified to compensate for fast QSB.

8) Audio hiss removed from audio circuit by adding more capacitors to
filter
out some of the higher audio frequencies. Thus, this gives the audio
more
punch and makes it easier to listen to. It also helps make up for the
cheap
built in speaker. An external, Good quality speaker is also recommended!

9)Using the frequency counter in my $3000 transceiver the USB and LSB
readouts have been adjusted on the DX-394 to show correct readout with
an
internal trimmer capacitor. Typically the frequency readout of the
DX-394
shows the center frequency rather than the actual frequency of the SSB
signal.

10)Audio Quality-Additional capacitors have been added to the audio
circuit
which give the radio real bass punch and make it sound like a real
communications receiver!

11)Hum Reduction-A 2200 uF capacitor is added to the power supply to
reduce
the hum heard with low audio gain commonly used with headphones. With
this
mod the hum disappears! Additional voltage regulation has been added to
the
power supply circuit to make the entire system more stable!

12) The top and bottom cases of the radio cabinet have been covered on
the
inside with conductive, aluminum tape that will reduce interference. RFI
produced from nearby broadcast stations, computers, TV's and computer
monitors is greatly reduced with this new mod. Birdies, spurious signals
and
heterodynes caused by these and other electronic devices is shielded out
by
this new aluminum tape's shielding.

Please let me know what you THINK!

Thanks for looking

Sounds like you did some nice mod's to your '394'. Are the details for
all of them available on the Net?


-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Most, if not all mods should be available on the net. Try google for "DX-394
Mods". I got my radio from lowbander(seller) on ebay. Look at this!!even
better deal as I didnt get the external speaker!!
http://cgi.ebay.com/ws/eBayISAPI.dll...tegory=15 051


John


"starman" wrote in message
...
john wrote:

Hi guys and gals. Pretty new to shortwave and I know its late to be
asking
but how many of you use a DX-394 communications receiver and what do you
think about it?
I paid $250 for mine on ebay (prolly too much) with a lot of mods done
to it
and got the super Zepp shortwave antwnna. Here are the mods!
1) SWITCHABLE I.F. FILTERS-A switch has been installed to the front
panel,
using the Noise blanker switch of the radio that allows listeners to
choose
between Wide or Narrow Bandwidths! The two I.F. Filters have been set up
on
a switch so that you can listen to the wide AM filter for casual, easy
listening or flip over to a narrow bandwidth for Dxing or for listening
to
weak signals on a crowded band! The Bandwidth of the narrow, outboard
filter
installed is a tight 3.5-4 KHZ, which is great for SSB and crowded SW
band
conditions.

2) The "Chuff Chuff" noise when fine tuning was stopped with a simple
mod.

3) Keyboard Beeps mod was done to stop the annoying Beeping.

4) Crosstalk Mod was done by adding components in the ceramic filter
circuit. This greatly reduces the problems from strong adjacent channel
interference or bleed thru from the filters. This narrows the bandwidth
by
adding more capacitors to the circuit around Q13 is the second part of
this
mod.

5) Weight added to Main tuning dial makes the radio feel like a "Real
Radio"
with a heavy flywheel dial. Approximately 4 oz. of lead was added to the
dial and helps the "Feel " of the dial.

6) RF Gain control mod provides better linearity when adjust gain of
radio.
This makes it much more flexible when tuning and listening to loud or
strong
SW signals. This mod had a big effect on the radio as well!

7) AGC mod done for a slower speed. This makes it easier to listen to on
AM
or Sideband. The original manufacturer had a very fast attack AGC speed.
Up
and down signals will not pump the audio sound unnatural now. In ham
lingo,
the AGC has been modified to compensate for fast QSB.

8) Audio hiss removed from audio circuit by adding more capacitors to
filter
out some of the higher audio frequencies. Thus, this gives the audio
more
punch and makes it easier to listen to. It also helps make up for the
cheap
built in speaker. An external, Good quality speaker is also recommended!

9)Using the frequency counter in my $3000 transceiver the USB and LSB
readouts have been adjusted on the DX-394 to show correct readout with
an
internal trimmer capacitor. Typically the frequency readout of the
DX-394
shows the center frequency rather than the actual frequency of the SSB
signal.

10)Audio Quality-Additional capacitors have been added to the audio
circuit
which give the radio real bass punch and make it sound like a real
communications receiver!

11)Hum Reduction-A 2200 uF capacitor is added to the power supply to
reduce
the hum heard with low audio gain commonly used with headphones. With
this
mod the hum disappears! Additional voltage regulation has been added to
the
power supply circuit to make the entire system more stable!

12) The top and bottom cases of the radio cabinet have been covered on
the
inside with conductive, aluminum tape that will reduce interference. RFI
produced from nearby broadcast stations, computers, TV's and computer
monitors is greatly reduced with this new mod. Birdies, spurious signals
and
heterodynes caused by these and other electronic devices is shielded out
by
this new aluminum tape's shielding.

Please let me know what you THINK!

Thanks for looking

Sounds like you did some nice mod's to your '394'. Are the details for
all of them available on the Net?


-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

"starman" wrote in message
...
john wrote:

Hi guys and gals. Pretty new to shortwave and I know its late to be
asking
but how many of you use a DX-394 communications receiver and what do you
think about it?
I paid $250 for mine on ebay (prolly too much) with a lot of mods done
to it
and got the super Zepp shortwave antwnna. Here are the mods!
1) SWITCHABLE I.F. FILTERS-A switch has been installed to the front
panel,
using the Noise blanker switch of the radio that allows listeners to
choose
between Wide or Narrow Bandwidths! The two I.F. Filters have been set up
on
a switch so that you can listen to the wide AM filter for casual, easy
listening or flip over to a narrow bandwidth for Dxing or for listening
to
weak signals on a crowded band! The Bandwidth of the narrow, outboard
filter
installed is a tight 3.5-4 KHZ, which is great for SSB and crowded SW
band
conditions.

2) The "Chuff Chuff" noise when fine tuning was stopped with a simple
mod.

3) Keyboard Beeps mod was done to stop the annoying Beeping.

4) Crosstalk Mod was done by adding components in the ceramic filter
circuit. This greatly reduces the problems from strong adjacent channel
interference or bleed thru from the filters. This narrows the bandwidth
by
adding more capacitors to the circuit around Q13 is the second part of
this
mod.

5) Weight added to Main tuning dial makes the radio feel like a "Real
Radio"
with a heavy flywheel dial. Approximately 4 oz. of lead was added to the
dial and helps the "Feel " of the dial.

6) RF Gain control mod provides better linearity when adjust gain of
radio.
This makes it much more flexible when tuning and listening to loud or
strong
SW signals. This mod had a big effect on the radio as well!

7) AGC mod done for a slower speed. This makes it easier to listen to on
AM
or Sideband. The original manufacturer had a very fast attack AGC speed.
Up
and down signals will not pump the audio sound unnatural now. In ham
lingo,
the AGC has been modified to compensate for fast QSB.

8) Audio hiss removed from audio circuit by adding more capacitors to
filter
out some of the higher audio frequencies. Thus, this gives the audio
more
punch and makes it easier to listen to. It also helps make up for the
cheap
built in speaker. An external, Good quality speaker is also recommended!

9)Using the frequency counter in my $3000 transceiver the USB and LSB
readouts have been adjusted on the DX-394 to show correct readout with
an
internal trimmer capacitor. Typically the frequency readout of the
DX-394
shows the center frequency rather than the actual frequency of the SSB
signal.

10)Audio Quality-Additional capacitors have been added to the audio
circuit
which give the radio real bass punch and make it sound like a real
communications receiver!

11)Hum Reduction-A 2200 uF capacitor is added to the power supply to
reduce
the hum heard with low audio gain commonly used with headphones. With
this
mod the hum disappears! Additional voltage regulation has been added to
the
power supply circuit to make the entire system more stable!

12) The top and bottom cases of the radio cabinet have been covered on
the
inside with conductive, aluminum tape that will reduce interference. RFI
produced from nearby broadcast stations, computers, TV's and computer
monitors is greatly reduced with this new mod. Birdies, spurious signals
and
heterodynes caused by these and other electronic devices is shielded out
by
this new aluminum tape's shielding.

Please let me know what you THINK!

Thanks for looking

Sounds like you did some nice mod's to your '394'. Are the details for
all of them available on the Net?

I dont thing John did the actual mods, they were done by the Ebay seller, I
had this same radio on my watch list. :-) You can find most of these mods
on www.mods.dk

MnMikew wrote:
[snip]
Sounds like you did some nice mod's to your '394'. Are
the details for all of them available on the Net?

I dont thing John did the actual mods, they were done by
the Ebay seller, I had this same radio on my watch list.
:-) You can find most of these mods on www.mods.dk

Better yet is http://groups.yahoo.com/group/RADIOSHACKDX394/ . The mods on
www.mods.dk are a subset of the mods in the group, some of which have been
updated. Plus you can join a 570 member community of users, review an
archive of some 2100 messages, etc.

Tom

john wrote in message
news:0pWMb.44127$5V2.62848@attbi_s53...
Hi guys and gals. Pretty new to shortwave and I know its late to be asking
but how many of you use a DX-394 communications receiver and what do you
think about it?
I paid $250 for mine on ebay (prolly too much) with a lot of mods done to
it
and got the super Zepp shortwave antwnna. Here are the mods!
1) SWITCHABLE I.F. FILTERS-A switch has been installed to the front panel,
using the Noise blanker switch of the radio that allows listeners to
choose
between Wide or Narrow Bandwidths! The two I.F. Filters have been set up
on
a switch so that you can listen to the wide AM filter for casual, easy
listening or flip over to a narrow bandwidth for Dxing or for listening to
weak signals on a crowded band! The Bandwidth of the narrow, outboard
filter
installed is a tight 3.5-4 KHZ, which is great for SSB and crowded SW band
conditions.

2) The "Chuff Chuff" noise when fine tuning was stopped with a simple mod.

Good mod.

3) Keyboard Beeps mod was done to stop the annoying Beeping.

4) Crosstalk Mod was done by adding components in the ceramic filter
circuit. This greatly reduces the problems from strong adjacent channel
interference or bleed thru from the filters. This narrows the bandwidth by
adding more capacitors to the circuit around Q13 is the second part of
this
mod.

The bandwidth is defined by the filter itself.................you can't
narrow the bandwidth. You can only eliminate the feedaround problem.

5) Weight added to Main tuning dial makes the radio feel like a "Real
Radio"
with a heavy flywheel dial. Approximately 4 oz. of lead was added to the
dial and helps the "Feel " of the dial.

6) RF Gain control mod provides better linearity when adjust gain of
radio.
This makes it much more flexible when tuning and listening to loud or
strong
SW signals. This mod had a big effect on the radio as well!

RF gain isn't that necessary a control, unless you are disabling the AGC. It
might be ok, if you want to eliminate the background noise, but then you
lose AGC control. We are dealing with a closed loop system here.

7) AGC mod done for a slower speed. This makes it easier to listen to on
AM
or Sideband. The original manufacturer had a very fast attack AGC speed.
Up
and down signals will not pump the audio sound unnatural now. In ham
lingo,
the AGC has been modified to compensate for fast QSB.

Good mod, if it is switchable.

8) Audio hiss removed from audio circuit by adding more capacitors to
filter
out some of the higher audio frequencies. Thus, this gives the audio more
punch and makes it easier to listen to. It also helps make up for the
cheap
built in speaker. An external, Good quality speaker is also recommended!

Once again, good mod, if it is switchable; otherwise, you lose high
frequency response. I never noticed a problem with any of my units.

9)Using the frequency counter in my $3000 transceiver the USB and LSB
readouts have been adjusted on the DX-394 to show correct readout with an
internal trimmer capacitor. Typically the frequency readout of the DX-394
shows the center frequency rather than the actual frequency of the SSB
signal.


10)Audio Quality-Additional capacitors have been added to the audio
circuit
which give the radio real bass punch and make it sound like a real
communications receiver!

Why would they add additional capacitors............you only need to
INCREASE the size of the coupling capacitors in order to lower the corner
frequency. (1/2PI RC).

11)Hum Reduction-A 2200 uF capacitor is added to the power supply to
reduce
the hum heard with low audio gain commonly used with headphones. With this
mod the hum disappears! Additional voltage regulation has been added to
the
power supply circuit to make the entire system more stable!

This receiver never had any stability problems. If you really did want to
improve the stability, replace the trimmer capacitors with Voltronics
multi-turn piston capacitors.

12) The top and bottom cases of the radio cabinet have been covered on the
inside with conductive, aluminum tape that will reduce interference. RFI
produced from nearby broadcast stations, computers, TV's and computer
monitors is greatly reduced with this new mod. Birdies, spurious signals
and
heterodynes caused by these and other electronic devices is shielded out
by
this new aluminum tape's shielding.

This was ok from a shielding standpoint, but now the internal loopstick has
been rendered useless. It is now enclosed in a shield!

Please let me know what you THINK!


Not a bad deal for 150 dollars..................you overpaid, but still it
isn't too bad of a radio. Probably, one of the biggest flaws of the design
are the front end filters. Instead of using even a 3 branch type of filter,
the designer decided to use a simple tunable LC filter. This would be ok in
a 50 dollar portable, but is not the way to go in a receiver that originally
was attempted to sell for 400 dollars. The glass epoxy boards are a good
idea. In the Chicago area hamfests, this receiver typically goes for 100 to
150 dollars.

Pete

I hope I didn't sound too negative in my last reply.............actually the
394 isn't a bad receiver. For those who might be interested, I can redesign
the input filters, using a 3 branch chebychev topology. Just shoot me the
filter limits that are given in the service manual, and I can do that. It
will turn a fair receiver into a very good receiver. I won't charge for this
service........there are enough of you out there that can benefit from it!

Pete

Maximus wrote in message
nk.net...
I like my DX 394 even without mods, and I have not had any done S. I
suppose modifying is cheaper than spending $1000 or more for a radio S.
I
think you will like it. Now, if you have a good antenna and the receiver
is
grounded you should be all set to listen. Hopefully the ionosphere will
cooperate for you g.
V
"starman" wrote in message
...
john wrote:

Hi guys and gals. Pretty new to shortwave and I know its late to be
asking
but how many of you use a DX-394 communications receiver and what do
you
think about it?
I paid $250 for mine on ebay (prolly too much) with a lot of mods done
to it
and got the super Zepp shortwave antwnna. Here are the mods!
1) SWITCHABLE I.F. FILTERS-A switch has been installed to the front
panel,
using the Noise blanker switch of the radio that allows listeners to
choose
between Wide or Narrow Bandwidths! The two I.F. Filters have been set
up
on
a switch so that you can listen to the wide AM filter for casual, easy
listening or flip over to a narrow bandwidth for Dxing or for
listening
to
weak signals on a crowded band! The Bandwidth of the narrow, outboard
filter
installed is a tight 3.5-4 KHZ, which is great for SSB and crowded SW
band
conditions.

2) The "Chuff Chuff" noise when fine tuning was stopped with a simple
mod.

3) Keyboard Beeps mod was done to stop the annoying Beeping.

4) Crosstalk Mod was done by adding components in the ceramic filter
circuit. This greatly reduces the problems from strong adjacent
channel
interference or bleed thru from the filters. This narrows the
bandwidth
by
adding more capacitors to the circuit around Q13 is the second part of
this
mod.

5) Weight added to Main tuning dial makes the radio feel like a "Real
Radio"
with a heavy flywheel dial. Approximately 4 oz. of lead was added to
the
dial and helps the "Feel " of the dial.

6) RF Gain control mod provides better linearity when adjust gain of
radio.
This makes it much more flexible when tuning and listening to loud or
strong
SW signals. This mod had a big effect on the radio as well!

7) AGC mod done for a slower speed. This makes it easier to listen to
on
AM
or Sideband. The original manufacturer had a very fast attack AGC
speed.
Up
and down signals will not pump the audio sound unnatural now. In ham
lingo,
the AGC has been modified to compensate for fast QSB.

8) Audio hiss removed from audio circuit by adding more capacitors to
filter
out some of the higher audio frequencies. Thus, this gives the audio
more
punch and makes it easier to listen to. It also helps make up for the
cheap
built in speaker. An external, Good quality speaker is also
recommended!

9)Using the frequency counter in my $3000 transceiver the USB and LSB
readouts have been adjusted on the DX-394 to show correct readout with
an
internal trimmer capacitor. Typically the frequency readout of the
DX-394
shows the center frequency rather than the actual frequency of the SSB
signal.

10)Audio Quality-Additional capacitors have been added to the audio
circuit
which give the radio real bass punch and make it sound like a real
communications receiver!

11)Hum Reduction-A 2200 uF capacitor is added to the power supply to
reduce
the hum heard with low audio gain commonly used with headphones. With
this
mod the hum disappears! Additional voltage regulation has been added
to
the
power supply circuit to make the entire system more stable!

12) The top and bottom cases of the radio cabinet have been covered on
the
inside with conductive, aluminum tape that will reduce interference.
RFI
produced from nearby broadcast stations, computers, TV's and computer
monitors is greatly reduced with this new mod. Birdies, spurious
signals
and
heterodynes caused by these and other electronic devices is shielded
out
by
this new aluminum tape's shielding.

Please let me know what you THINK!

Thanks for looking

Sounds like you did some nice mod's to your '394'. Are the details for
all of them available on the Net?


-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

if anyone is interested in getting a 394, I have one that is modded
with only what is necessary, has a great SWL IF filter and configured
for great sound. it is only $199 with a nice speaker and antenna. no
need to pay $250 ! I make the BEST sounding 394's and this is not BS
!!!!! I use a high end SWL filter and upgrade the speaker and DO NOT
do the hiss mod which screws up the sound !!!





"john" wrote in message news:0pWMb.44127$5V2.62848@attbi_s53...
Hi guys and gals. Pretty new to shortwave and I know its late to be asking
but how many of you use a DX-394 communications receiver and what do you
think about it?
I paid $250 for mine on ebay (prolly too much) with a lot of mods done to it
and got the super Zepp shortwave antwnna. Here are the mods!
1) SWITCHABLE I.F. FILTERS-A switch has been installed to the front panel,
using the Noise blanker switch of the radio that allows listeners to choose
between Wide or Narrow Bandwidths! The two I.F. Filters have been set up on
a switch so that you can listen to the wide AM filter for casual, easy
listening or flip over to a narrow bandwidth for Dxing or for listening to
weak signals on a crowded band! The Bandwidth of the narrow, outboard filter
installed is a tight 3.5-4 KHZ, which is great for SSB and crowded SW band
conditions.

2) The "Chuff Chuff" noise when fine tuning was stopped with a simple mod.

3) Keyboard Beeps mod was done to stop the annoying Beeping.

4) Crosstalk Mod was done by adding components in the ceramic filter
circuit. This greatly reduces the problems from strong adjacent channel
interference or bleed thru from the filters. This narrows the bandwidth by
adding more capacitors to the circuit around Q13 is the second part of this
mod.

5) Weight added to Main tuning dial makes the radio feel like a "Real Radio"
with a heavy flywheel dial. Approximately 4 oz. of lead was added to the
dial and helps the "Feel " of the dial.

6) RF Gain control mod provides better linearity when adjust gain of radio.
This makes it much more flexible when tuning and listening to loud or strong
SW signals. This mod had a big effect on the radio as well!

7) AGC mod done for a slower speed. This makes it easier to listen to on AM
or Sideband. The original manufacturer had a very fast attack AGC speed. Up
and down signals will not pump the audio sound unnatural now. In ham lingo,
the AGC has been modified to compensate for fast QSB.

8) Audio hiss removed from audio circuit by adding more capacitors to filter
out some of the higher audio frequencies. Thus, this gives the audio more
punch and makes it easier to listen to. It also helps make up for the cheap
built in speaker. An external, Good quality speaker is also recommended!

9)Using the frequency counter in my $3000 transceiver the USB and LSB
readouts have been adjusted on the DX-394 to show correct readout with an
internal trimmer capacitor. Typically the frequency readout of the DX-394
shows the center frequency rather than the actual frequency of the SSB
signal.

10)Audio Quality-Additional capacitors have been added to the audio circuit
which give the radio real bass punch and make it sound like a real
communications receiver!

11)Hum Reduction-A 2200 uF capacitor is added to the power supply to reduce
the hum heard with low audio gain commonly used with headphones. With this
mod the hum disappears! Additional voltage regulation has been added to the
power supply circuit to make the entire system more stable!

12) The top and bottom cases of the radio cabinet have been covered on the
inside with conductive, aluminum tape that will reduce interference. RFI
produced from nearby broadcast stations, computers, TV's and computer
monitors is greatly reduced with this new mod. Birdies, spurious signals and
heterodynes caused by these and other electronic devices is shielded out by
this new aluminum tape's shielding.

Please let me know what you THINK!



Thanks for looking

Pete KE9OA wrote:
I hope I didn't sound too negative in my last
reply.............actually the 394 isn't a bad receiver.
For those who might be interested, I can redesign the
input filters, using a 3 branch chebychev topology. Just
shoot me the filter limits that are given in the service
manual, and I can do that. It will turn a fair receiver
into a very good receiver. I won't charge for this
service........there are enough of you out there that can
benefit from it!

Hi Pete, I'm interested. I have been intending to build an outboard set of
filters that would be diode switched under the control of the receiver, just
as the internal filters are controlled. Was thinking of doubling the number
of filters to narrow the individual passbands for even better protection
from overload. Would control this sub-band switching by comparison against
the voltage applied to the varactor. As I have never designed and built this
sort of thing before, I'd be happy to have your guidance. I'll e-mail you
off list with the frequencies.

Tom