[Hallicrafters] Re: SX-100 oval power cord, etc

[kiyoinc at attglobal.net]

** Reply to note from <shortwaves at msn.com> Wed, 21 Jul 2004 04:00:04 -0400 (EDT)

>  I had not ever seen a  
> three-conductor power cord with or without a chassis plug-and-jack  
> termination used on the SX-100 as factory original...The SX-100 that I have  
> is an earlier mk2 (a mk2 having factory installed original-style mk1 and  
> earlier mk2 knobs as opposed to the later SX-115 style knobs) has a  
> two-conductor cord thru the rear apron, hardwired to the power supply mains  
> circuit...Have I missed something here? 

A co-worker gave me my SX-100 last year.  Call it an "adoption", free
to a good home.  I don't know its history except that he's had it for
a long time.  He's likely not the original owner. 

He did add an external digital display, 1 kHz readout, more on that
later.  

The front and rear panel markings and tags say, "SX-100".  Nothing
about Mark I, II.  

The manual, original Halli-imprint, says SX-100 mark II.  The rear
picture shows a two-wire cord leaving a standard strain relief hole
next to the octal socket.

The radio is not "mint" but in excellent shape. It has a three
wire power socket next to the octal socket. It looks "factory" from
the outside.  I have not pulled the case off to investigate further.

It seems like an odd mod for an owner to make.  I can't imagine
someone deciding one day that they want to cut the power cord off and
install a socket and detachable AC cord.  Drilling and filing the
rear chassis.  Riveting the socket using factory-style rivets, not
nuts and bolts or pop-rivets. 

If there was a problem with the original AC cord, it would make more
sense to replace it.  Solder in a new, identical cord. 

That 3 wire, round connector dates from the 1960's, perhaps 1950's.
After about 1980, I doubt that anyone would have selected it over,
say, the now ubiquitous IEC connector. 

The SX-100's detachable AC cord is in good shape.  My SB-303/313's
have "good enough" AC cords, they work but are starting to feel, ah,
gummy in spots, especially near the connectors.  
  
> Additional ramblings: 
>  
> It took me a long, long time to find an SX-100 in good, totally original  
> condition and insofar as I am still in the restoration process of mine and  
> therefore cannot comment on its frequency stability, I have read many, many  
> comments about drifting issues over the years and had assumed these issues  
> were founded on the experience of those who were trying to achieve, for  
> example, drift-free reception of SSB transmissions... ...

Yeah, In perhaps 20 hours of listening to both CW and SSB on 40 and
75/80, I have no complaints.  I have SB-303's and other extremely
stable radios.  I have put an SB-303 on a frequency counter.  It
stayed within 200 Hz over a week.  

Electro-mechanical variable oscillators can be stable enough to
simulate crystal-oven performance, as far as you can tell by ear in
real world conditions.   

I don't expect an SX-100 to be as stable as the SB-303 because
the 303 is solid state and has an electronic voltage regulator.  I'm
guessing that after a 20 minute warm up, the SX-100 will be close to
SB-303 performance, good enough to tune in AM, set and forget. 
  
> The SX-100 was not only the flag-ship receiver of the Halli line for nearly  
> two years (1955-56), but also remained in production until at least 1961  
> (source 1961 ARRL Handbook) as its top general coverage receiver...It seems  
> to me, that had there been intolerable drifting issues during this  
> relatively long period, the word would have circulated among prospective  
> buyers of a communications receiver at the time, causing them to look  
> elsewhere...Perhaps--for the shear numbers sold--other alternatives for such  
> a features-rich general coverage receiver in the 300 dollar price range were  
> not available.

Another odd thing about my SX-100 are the Tune and Notch knobs. These
are unlabeled but very Halli-look knobs with Allen, not spline
setscrews.  

If this was a user mod, someone woke up one morning and decided to
replace the spline setscrewed, labeled knobs with 90% look-alike knobs
with Allen setscrews.

I've seen people searching for "original" labeled knobs for the
SX-100.  I'm guessing that Halli was short knobs for a production run
and substituted these and the look-alikes are a factory variation. 

I don't think the radios with the look-alike knobs are more valuable
but they are not less valuable either.  Either style knobs work well
and look well.  If factory, it's simply a sylistic variation. 

de ah6gi/4