1000+ Members - Group for Radio Shack DX-394 Users
Tom Holden
links to related websites, documentation, and photos along with a user
survey and a message forum (4000+ messages archived) to help you get the
most
fun and DX out of your Realistic / Radio Shack DX-394, DX394, DX 394.
Over 90 mods and tips now listed plus a dozen on the To Do or Wish List.
More mods than for any other general coverage receiver! Thoroughly
documented with a Master Index. If you like to tinker with radios, I know of
no other recent model that lends itself to as much fun in this arena as the
DX-394. Great platform for learning radio-electronics. Always 1 or more FA
on eBay.
Active & friendly user community now with over 1000 members. Some members
are
keen short wave listeners; others are into AM DXing and a few enjoy long
wave. Many experiment with antennas and some are ardent modifiers -
customising and souping up the rig as hot rodders would do with cars. You'll
find lots to interest you and help get the most out of your radio.
All here at:
http://groups.yahoo.com/group/苧ADIOSHACKDX394/
Subscribe on line (for full access privileges to the extensive collection of
Files, Photos and Links) or by email:
RADIOSHACKDX394-subscribe@yaho觔groups.com (for message posting/receipt
only).
73, Tom
RHF
Radio Shack DX-394 User's Group
RadioShack DX394 {DX 394}
DX-394 => http://tinyurl.com/o6rgr
Radio Shack DX-394 User's Group
RadioShack DX394 {DX 394}
http://groups.yahoo.com/group/RADIOSHACKDX394/
Radio Shack DX-394 User's Group
RadioShack DX394 {DX 394}
<http://groups.yahoo.com/group/RADIOSHACKDX394/>
RigPix DataBase listing for the
Radio Shack DX-394 [DX394 DX 394]
http://www.rigpix.com/rs-realistic/realistic_dx394.htm
ABOUT - Radio Shack DX-394 Shortwave Radio
http://groups.google.com/group/rec.radio.shortwave/msg/73a2da4123a74125
just my two cents worth - jm2cw ~ RHF
.
.
. .
.
Han
that is an impressibe amount of subscribers. i think mostly US in
europe this is not the most poppular receiver.
With kind regards
Han The Netherlands.
You can also visit my website with a lot of recordings of rediostations
under 30 MHz.
Jack Ricci
mistakes? I get the message that this group does not exist...
Jack
"Tom Holden" <holden...@sympatico.ca> wrote in message
news:WxJVf.448$u15.1...@news20.bellglobal.com...
> This group has the most complete collection of modifications, usage tips,
> links to related websites, documentation, and photos along with a user
> survey and a message forum (4000+ messages archived) to help you get the
> most
> fun and DX out of your Realistic / Radio Shack DX-394, DX394, DX 394.
>
> Over 90 mods and tips now listed plus a dozen on the To Do or Wish List.
> More mods than for any other general coverage receiver! Thoroughly
> documented with a Master Index. If you like to tinker with radios, I know
> of
> no other recent model that lends itself to as much fun in this arena as
> the
> DX-394. Great platform for learning radio-electronics. Always 1 or more FA
> on eBay.
>
> Active & friendly user community now with over 1000 members. Some members
> are
> keen short wave listeners; others are into AM DXing and a few enjoy long
> wave. Many experiment with antennas and some are ardent modifiers -
> customising and souping up the rig as hot rodders would do with cars.
> You'll
> find lots to interest you and help get the most out of your radio.
>
> All here at:
> http://groups.yahoo.com/group/ÂRADIOSHACKDX394/
>
> Subscribe on line (for full access privileges to the extensive collection
> of Files, Photos and Links) or by email:
> RADIOSHACKDX394-subscribe@yahoÂogroups.com (for message posting/receipt
> only).
>
> 73, Tom
>
Caveat Lector
Just FYI: I see a lot of these mods to increase sensitivity -- resulting in
trashing the dynamic range
Remember some of these mods are made by amateurs
The factory engineers designed the sensitivity for very good reasons
--
CL -- I doubt, therefore I might be !
"Tom Holden" <holden...@sympatico.ca> wrote in message
news:WxJVf.448$u15.1...@news20.bellglobal.com...
> This group has the most complete collection of modifications, usage tips,
> links to related websites, documentation, and photos along with a user
> survey and a message forum (4000+ messages archived) to help you get the
> most
> fun and DX out of your Realistic / Radio Shack DX-394, DX394, DX 394.
>
> Over 90 mods and tips now listed plus a dozen on the To Do or Wish List.
> More mods than for any other general coverage receiver! Thoroughly
> documented with a Master Index. If you like to tinker with radios, I know
> of
> no other recent model that lends itself to as much fun in this arena as
> the
> DX-394. Great platform for learning radio-electronics. Always 1 or more FA
> on eBay.
>
> Active & friendly user community now with over 1000 members. Some members
> are
> keen short wave listeners; others are into AM DXing and a few enjoy long
> wave. Many experiment with antennas and some are ardent modifiers -
> customising and souping up the rig as hot rodders would do with cars.
> You'll
> find lots to interest you and help get the most out of your radio.
>
> All here at:
> http://groups.yahoo.com/group/ÂRADIOSHACKDX394/
>
> Subscribe on line (for full access privileges to the extensive collection
> of Files, Photos and Links) or by email:
> RADIOSHACKDX394-subscribe@yahoÂogroups.com (for message posting/receipt
> only).
>
> 73, Tom
>
Jack Ricci
Radio Shack DX-394 User's Group
RadioShack DX394 {DX 394}
DX-394 => http://tinyurl.com/o6rgr
Radio Shack DX-394 User's Group
RadioShack DX394 {DX 394}
http://groups.yahoo.com/group/RADIOSHACKDX394/
OOOoooopps! Correction noted. Thanks.
Jack
"Jack Ricci" <ri...@mnsi.net> wrote in message
news:e08n5...@enews4.newsguy.com...
Tom Holden
news:giSVf.14367$6a1.6434@fed1read04...
>
> Just FYI: I see a lot of these mods to increase sensitivity -- resulting
> in trashing the dynamic range
Which of these mods do you think increase sensitivity at the expense of
dynamic range?
> Remember some of these mods are made by amateurs
Many of whom are electronics professionals. That's not to say that novices
at electronics do not carry out some mods. One of the virtues of the DX-394
is that it can be readily modified and doing so is a great educational
activity for someone getting into radio and electronics.
> The factory engineers designed the sensitivity for very good reasons
And made some mistakes in other areas, e.g., decoupling around the IF
filters, AGC time constant for SSB (factory corrected in the revised
versions), and some design trade-offs or decisions that owners want to
correct. That is true of every product.
> --
> CL -- I doubt, therefore I might be !
And I was named after the biblical doubter.
Tom
Caveat Lector
http://www.elecraft.com/K2_perf.htm
Sez
MDS = Minimum Discernible Signal (3db increase above noise floor). Larger
negative numbers are generally better, but too much sensitivity can reduce
strong signal dynamic range and Ip3. Pre-Amp On MDS numbers of -130 dBm or
more are more than adequate for most HF band operating, since band noise is
typically above this number. (Lower frequencies need less MDS (more +number)
due to an increase in atmospheric noise.)
--
CL -- I doubt, therefore I might be !
"Tom Holden" <holden...@sympatico.ca> wrote in message
news:_8VVf.620$u15.1...@news20.bellglobal.com...
clifto
> Just FYI: I see a lot of these mods to increase sensitivity -- resulting in
> trashing the dynamic range
>
> Remember some of these mods are made by amateurs
>
> The factory engineers designed the sensitivity for very good reasons
Problem is, many times those reasons have more to do with cost than
with performance.
--
All relevant people are pertinent.
All rude people are impertinent.
Therefore, no rude people are relevant.
-- Solomon W. Golomb
Tom Holden
>I refer you to the Elecraft page
> http://www.elecraft.com/K2_perf.htm
>
> Sez
> MDS = Minimum Discernible Signal (3db increase above noise floor). Larger
> negative numbers are generally better, but too much sensitivity can reduce
> strong signal dynamic range and Ip3. Pre-Amp On MDS numbers of -130 dBm or
> more are more than adequate for most HF band operating, since band noise
> is typically above this number. (Lower frequencies need less MDS (more
> +number) due to an increase in atmospheric noise.)
>
>
> --
> CL -- I doubt, therefore I might be !
I have no dispute with that. Rather with your first comment:
>>> Just FYI: I see a lot of these mods to increase sensitivity -- resulting
>>> in trashing the dynamic range
>>
>>
>> Which of these mods do you think increase sensitivity at the expense of
>> dynamic range?
You did not answer the question. The answer may well be 'none'. I'm not
aware of any aimed at increased sensitivity, unless adding an amplified
preselector counts as a mod. And that could arguably be for improved dynamic
range and sensitivity by improving front-end selectivity and noise figure.
Most regard the DX-394 as a very sensitive receiver that is outperformed in
that spec by few others. But itcould do with improved overload threshold and
IP3.
Methinks you might be trashing imagined mods rather than the ones
well-documented in the user group.
Tom
Caveat Lector
post'Gotta be more careful
--
CL -- I doubt, therefore I might be !
"Never anonymous Bud" <new...@katxyzkave.net> wrote in message
news:06kg229qmd9mikh33...@4ax.com...
> On Mon, 27 Mar 2006 13:29:12 -0600, clifto <cli...@gmail.com> wrote:
>
>>Caveat Lector wrote:
>>> Just FYI: I see a lot of these mods to increase sensitivity -- resulting
>>> in
>>> trashing the dynamic range
>>>
>>> Remember some of these mods are made by amateurs
>>>
>>> The factory engineers designed the sensitivity for very good reasons
>>
>>Problem is, many times those reasons have more to do with cost than
>>with performance.
>
> My question would be...
>
> WHAT does this have to do with scanning,
> and WHY was it cross-posted to 6 newsgroups??
>
>
>
>
>
>
> Lumber Cartel (tinlc) #2063. Spam this account at your own risk.
>
> This sig censored by the Office of Home and Land Insecurity...
>
> Remove XYZ to email me
Caveat Lector
So I didn't read any of the mods
My FYI was a general info to be careful of mods having to do with
sensitivity.
Perhaps there are none for this radio as you pointed out.
I would feel much more comfortable if a modder would measure and present all
the receiver specs after the mod, one seldom sees that
So be careful, the mod you make - may or may not have been thoroughly
thought out and properly implemented
I double checked my statements with a friend who has designed receivers of
all types for many years and he concurs.
So be aware of what you are doing to the entire receiver specifications when
you make mod.
Case closed
--
CL -- I doubt, therefore I might be !
"Tom Holden" <holden...@sympatico.ca> wrote in message
news:jTXVf.736$u15.1...@news20.bellglobal.com...
Tom Holden
news:06kg229qmd9mikh33...@4ax.com...
>
>
> WHAT does this have to do with scanning,
> and WHY was it cross-posted to 6 newsgroups??
The DX-394 is a scanning receiver, reviews have described its user interface
as reflecting a scanner heritage, it has been a topic in all the newsgroups
to which I posted the notice, and similar notices have been crossposted a
few times in all these newsgroups informing potentially interested parties
about http://groups.yahoo.com/group/RADIOSHACKDX394/, without objection.
Are there any other newsgroups for which it would be relevant? The ones I
posted to are:
rec.radio.shortwave, alt.radio.scanner, alt.radio.scanner.uk,
rec.radio.amateur.equipment, rec.radio.amateur.homebrew
73, Tom
Tom Holden
>I don't want to join this group as I don't own this radio.
> So I didn't read any of the mods
As I thought.
> My FYI was a general info to be careful of mods having to do with
> sensitivity.
OK and I concur with your general comment.
> Perhaps there are none for this radio as you pointed out.
That's about it - I've indexed over 90 and none of them are aimed at
increasing sensitivity. Several address overload mitigation.
> I would feel much more comfortable if a modder would measure and present
> all the receiver specs after the mod, one seldom sees that
Agreed. But not everyone is equipped to make these measurements. Many mods
are intuitively obvious and the subjective improvement is apparent even
though the absolute performance improvement is unmeasured.
> So be careful, the mod you make - may or may not have been thoroughly
> thought out and properly implemented
That's true. I have challenged mods, not included some in the Index or
qualified them with the potential side effects.
> I double checked my statements with a friend who has designed receivers of
> all types for many years and he concurs.
So do I.
> So be aware of what you are doing to the entire receiver specifications
> when you make mod.
Agreed
> Case closed
Thanks
> --
> CL -- I doubt, therefore I might be !
>
TH -- I doubt, before I believe ... ;-)
Butch Magee
> Just FYI: I see a lot of these mods to increase sensitivity -- resulting in
> trashing the dynamic range
>
> Remember some of these mods are made by amateurs
>
> The factory engineers designed the sensitivity for very good reasons
Thank you Mr. Lector for reminding the wannabe multi-year experienced
EEs that it is best to leave well enough alone.
Butch KF5DE
Telamon
> didn't read any of the mods My FYI was a general info to be careful
> of mods having to do with sensitivity. Perhaps there are none for
> this radio as you pointed out.
>
> I would feel much more comfortable if a modder would measure and
> present all the receiver specs after the mod, one seldom sees that
>
> So be careful, the mod you make - may or may not have been
> thoroughly thought out and properly implemented
>
> I double checked my statements with a friend who has designed
> receivers of all types for many years and he concurs.
>
> So be aware of what you are doing to the entire receiver
> specifications when you make mod.
>
> Case closed
I have not been into radio receiver design but it seems to me that the
radio as designed has a certain dynamic range and the mod Tom mentioned
would cause some loss. In this case some amplification would bring the
sensitivity back to what it was. This bandpass amplification example
should be able to improve the receiver front end as opposed to
broadband amplification. I have not looked at these modifications but
an additional preselection circuit with an amount of amplification to
make up for the preselection circuit loss should result in an overall
improvement. This certainly sounds like a good idea for a radio that
does not have a preselector circuit to begin with.
A more simplistic case of just providing more broadband amplification
where the receiver is already sensitive enough will plainly reduce the
"useful" dynamic range. Another example of merely providing this
broadband amplification to a receiver of poor sensitivity but good
dynamic range could result in an improvement.
Conclusion... it depends on other factors and what you are trying to
accomplish. The modifications would have to be judged on their design
and the state of the radio to begin with.
So... mods should be judged on a case by case basis.
--
Telamon
Ventura, California
Jack Ricci
I agree...and I'm a Canuck...
"Tom Holden" <holden...@sympatico.ca> wrote in message
news:tPYVf.772$u15.1...@news20.bellglobal.com...
Jack Ricci
> and WHY was it cross-posted to 6 newsgroups??
I was intrigued by that post and joined the group. DX 394 is quite a bit
part of a listening hobby.
The DX 394 scans a slightly different breed of frequencies...or does it?
My Yupiteru MVT 7100 picks up all those same frequencies also, and then
some. Does that mean my Yupi is technically NOT a scanner because I can also
use it as an AM/FM/SW/SSB/Weather/TV audio/
CB/Communications/Marine/Police/Fire/Ambulance radio receiver as well?
Jack
"Never anonymous Bud" <new...@katxyzkave.net> wrote in message
news:06kg229qmd9mikh33...@4ax.com...
> On Mon, 27 Mar 2006 13:29:12 -0600, clifto <cli...@gmail.com> wrote:
>
>>Caveat Lector wrote:
>>> Just FYI: I see a lot of these mods to increase sensitivity -- resulting
>>> in
>>> trashing the dynamic range
>>>
>>> Remember some of these mods are made by amateurs
>>>
>>> The factory engineers designed the sensitivity for very good reasons
>>
>>Problem is, many times those reasons have more to do with cost than
>>with performance.
>
> My question would be...
>
> WHAT does this have to do with scanning,
> and WHY was it cross-posted to 6 newsgroups??
>
>
>
>
>
>
Tom Holden
"Telamon" <telamon_s...@pacbell.net.is.invalid> wrote in message
news:telamon_spamshield-9...@newsclstr02.news.prodigy.com...
> I have not been into radio receiver design but it seems to me that the
> radio as designed has a certain dynamic range and the mod Tom mentioned
> would cause some loss. In this case some amplification would bring the
> sensitivity back to what it was. This bandpass amplification example
> should be able to improve the receiver front end as opposed to
> broadband amplification. I have not looked at these modifications but
> an additional preselection circuit with an amount of amplification to
> make up for the preselection circuit loss should result in an overall
> improvement. This certainly sounds like a good idea for a radio that
> does not have a preselector circuit to begin with.
I have generally recommended a passive preselector for use with the DX-394.
It would take a very good amplifier design along with the improved
selectivity to not degrade the overload and IP3 performance. The DX-394 has
an auto-tuned preselector but it is not very sharp - the total energy
delivered to its RF amplifier and 1st mixer is reduced by increasing
front-end selectivity, thereby reducing the probability of overload. Below
10-15 MHz, losses in the added preselector are likely of no consequence.
Above that, an additional pre-selector with a very quiet amplifier could
improve the overall noise figure (sensitivity). A good combination for many
receivers could be a passive preselector for under 10-15 MHz with a stage of
low-noise amplification that can be switched in for use above.
> A more simplistic case of just providing more broadband amplification
> where the receiver is already sensitive enough will plainly reduce the
> "useful" dynamic range. Another example of merely providing this
> broadband amplification to a receiver of poor sensitivity but good
> dynamic range could result in an improvement.
Adding broadband RF amplification ahead of a DX-394 would be retrograde, as
it would be for most radios.
> Conclusion... it depends on other factors and what you are trying to
> accomplish. The modifications would have to be judged on their design
> and the state of the radio to begin with.
>
> So... mods should be judged on a case by case basis.
Agreed.
Tom
Tom Holden
> On Mon, 27 Mar 2006 16:30:01 -0500, "Tom Holden"
> <holden...@sympatico.ca> wrote:
>
>>The DX-394 is a scanning receiver,
>
> in rec.radio.shortwave and NOT in any scanner newsgroup.
It is a LW, MW, SW receiver that scans. Is alt.radio.scanner restricted to
discussion of scanning receivers that can tune only above 30 MHz?
Do a search in alt.radio.scanner:
http://groups.google.com/group/alt.radio.scanner/search?q=DX-394+OR+DX394+or+%22DX+394%22&start=50&
- 66 threads found, dating from 1996.
>
> It's also NOT amateur equipment any more than it is a scanner,
> and CERTAINLY not 'homebrew'.
Why is the DX-394 NOT amateur equipment (I assume you mean 'amateur radio')?
It tunes the HF ham bands and does a credible job receiving the popular ham
modes on its own and is used with software to receive many digital modes. It
is found in many hamshacks. My first SW receiver was a 5-tube Heathkit AR-3
general coverage radio - it doesn't hold a candle to the DX-394 - but it was
the receiving part of my ham radio station.
I agree that the DX-394 itself is not 'homebrew' but the many mods are of
interest to some homebrewers as have the design discussions carried out in
rec.radio.amateur.homebrew.
When did you become the self-appointed policer of these newsgroups? As far
as I can tell, my original post was in the spirit of guidelines about
cross-posting. Your carrying on with this nonsensical criticism by
cross-posting replies is not.
End of discussion.
Tom