[Hallicrafters] SX71 MOD, a reprise

Wed Mar 8 15:50:57 EST 2006

Who said I took this from someone, YOU did. I was only passing on what I had
done to a restoration, and what I had come by on my own, no ones help.
 What YOU are doing is just plain harassment. You have a problem with me,
get it out in the open. Don't HIDE behind some trumped up charge or
allegation.
Duane, be a man, take responsibility for your actions.
Gary...
----- Original Message ----- 
From: "Duane Fischer, W8DBF" <dfischer at usol.com>
To: "Philip Atchley" <Beaconeer at sbcglobal.net>; "Magoo" <magoo at isp.ca>;
<hallicrafters at mailman.qth.net>
Sent: Wednesday, March 08, 2006 2:57 PM
Subject: Re: [Hallicrafters] SX71 MOD, a reprise


> Phil (and all)
>
> When someone takes the copyrighted work of another without permission, or
> does so with permission, you always credit the source and the author. To
do
> otherwise is theft and/or plagerism, depending on whether or not the
person
> taking said material 'claims' to be the author. What Gary Brown did was
> wrong and unethical.
>
> Whether it is donated or whether it is not, what is on the HCI web site is
> copyrighted under that entity. If someone wants to reprintn something,
they
> need to get permission from the Web Master first.
>
> Gary is just complaining because once again he got caught being dishonest
> and is trying to pass the buck elsewhere.
>
> The HCI policy is clearly stated. If you wish to reprint an item or photo,
> ask the Web Master first. Then credit the source and the author or
> contributor. What is there is for the benefit of all, but we also have an
> obligation to those who donate their work to protect it from theft, misuse
> etc. Not all of what is on the HCI web site is donated! Hence the "Get
> Permission First" policy.
>
> Duane Fischer, W8DBF
>
> ----- Original Message ----- 
> From: "Philip Atchley" <Beaconeer at sbcglobal.net>
> To: "Magoo" <magoo at isp.ca>; <hallicrafters at mailman.qth.net>
> Sent: Wednesday, March 08, 2006 10:14 AM
> Subject: [Hallicrafters] SX71 MOD, a reprise
>
>
> > Hi All,
> >
> > Sheesh, if I'd have realized what a firestorm all this was going to
create
> > I would have kept my mouth shut, or rather, my fingers off the keyboard!
> >
> > Anything that I submit or come up with, whether on my web site or via
> > Email, is for the full benefit of the boatanchor community.  The SX71
> > "mod" (which I first posted in the form of an Email and which was
> > subsequently copied to the HCI site with my approval) that I came up
with
> > was 'slightly' more than just the cathode resistor, I also changed the
> > screen bias etc. of the second stage.  Still, all pretty simple stuff.
> > All that the HCI folks did was copy my email to the Web-site and add
some
> > advertising pictures to make it interesting.
> >
> > As far as I'm concerned, the written part that I produced can be printed
> > and may be freely used anywhere so long as there isn't any monetary
> > compensation (though if it's copied to any web-site etc. I'd appreciate
> > credit).  So far as I know, the PICTURES ARE HCI PROPERTY and any needed
> > permission should be definitely be obtained to use them.
> >
> > Since I originally wrote the article, and only parts of it made it's
away
> > "around the circuit",  I'm re-posting a copy here from my own archives.
> > Enjoy!
> >
> > <Pasted in>
> > I decided to take a '2nd' look at the SX-71.  While it played quite well
I
> > never felt like it was doing all that a receiver with 3 IF stages should
> > do. Front end seemed sensitive enough, but overall gain and AGC action,
> > while a little better than 'most' receivers with 2 IF's like the
> > Hammarlund HQ-100, Halli SX-110 etc, just didn't seem to really have the
> > "punch".  After I overhauled Don's National NC183D that had 3 IF's and a
> > circuit design quite similar to the SX-71, that opinion was further
> > reinforced.  In that set I had to change a couple resistors (per factory
> > recommendation) to decrease the gain slightly as it was unstable.
> >
> > So anyway, I sat down with the schematic and tube manual to see if I
could
> > determine why it's gain seemed so modest for the tube lineup.  Didn't
take
> > me long to spot it.  The 2nd IF stage had it's tube cathode biased very
> > high and an unusually low screen Voltage on the screen grid.  So, I dug
> > out ye old trusty soldering iron and set the cathode resistor and screen
> > Voltage to the same level that the 1st and 3rd IF stages use, which is a
> > normal and expected value.  Voila! Gain and AGC action came up to my
> > expectations.  It won't affect overall sensitivity/noise figure as that
is
> > mostly determined by the RF amplifier and first mixer stages.  What it
> > does affect, especially on the higher frequencies is how well the AGC
> > performs and how high you need to turn the volume on the weak stations.
> > Before you always had to 'crank it up' on weak stations on the 17 &
21MHz
> > bands, which is why I nearly always used the Ameco Nuvistor preamp over
15
> > MHz.  The thing really sounds good now and that is without the preamp!
> >
> > The SX-71 is claimed to be the first double conversion set on the
market.
> > They also wanted the selectivity and perhaps a 'little' extra gain that
an
> > extra IF amplifier gave them.  I can think of no explanation of why the
> > receiver was purposely 'tamed down' by crippling the 2nd IF and putting
> > coils that are sub par for the BCB band in an otherwise hot set.
Perhaps
> > 3 IF stages were so rare back then that they felt the "little" added
boost
> > was sufficient, while now days we are used to all receivers having
several
> > AGC controlled stages that give superb AGC action.
> >
> > <end of article>
> >
> > 73 de Phil,  KO6BB
> > DX begins at the noise floor!
> >
> > THE BEACONEER'S LAIR:  http://www.geocities.com/ko6bb/
> > MY RADIO-LOGS:   http://www.geocities.com/ko6bb/Logs/
> > QSL GALLERY:       http://photobucket.com/albums/y123/KO6BB/
> > Merced, Central California,    37.3N  120.48W  CM97sh
> >
> >
> > ----- Original Message ----- 
> >
> >> Let's see if I have this sequence right-
> >>
> >> Someone discovers that changing a resistor in a stage leads to better
> >> performance and posts this for everyone's benefit.
> >>
> >> Someone else posts a message indicating that this mod is similar to one
> >> found in a pre-written article. That article is identified with a link
> >> for everyone to see.
> >>
> >> The author of this earlier article contacts the list administrator to
> >> protest that someone has hijacked his material without giving him
credit.
> >>
> >> Right so far?  OK-so if I discover a mod for a radio and post it for
> >> everyone's benefit, not knowing that someone else has "discovered" this
> >> earlier and written an article on it then I am contravening "copyright"
> >> laws?
> >>
> >> Horse puckey!!  Let's get real!  I know Americans are a litiginous
> >> society but let's not get carried away here.  This is ham radio, not
the
> >> great Blackberry steal.
> >>
> >> Bill, VE3NH
> >
> > ______________________________________________________________
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> > List Administrator: Duane Fischer, W8DBF **for assistance**
> > dfischer at usol.com
> > ----
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> >
> >
> >
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>
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