[Central-Electronics] Central-Electronics Digest, Vol 67, Issue 5

Mon Nov 9 16:29:56 EST 2009

Correction folks.  Wes Schum started Central Elec

In a message dated 11/9/2009 12:04:55 P.M. Central Standard Time,  
central-electronics-request at mailman.qth.net writes:

Send  Central-Electronics mailing list submissions to
central-electronics at mailman.qth.net

To subscribe or unsubscribe via the  World Wide Web, visit
http://mailman.qth.net/mailman/listinfo/central-electronics
or, via email,  send a message with subject or body 'help' to
central-electronics-request at mailman.qth.net

You can reach the person  managing the list at
central-electronics-owner at mailman.qth.net

When replying, please edit  your Subject line so it is more specific
than "Re: Contents of  Central-Electronics digest..."

Today's Topics:

1. Re: 10B Mod (Jim Candela)
2. Re: 10B Mod  (k7fm)

----------------------------------------------------------------------

Message:  1
Date: Sun, 8 Nov 2009 12:44:42 -0600
From: "Jim Candela"  <jcandela at prodigy.net>
Subject: Re: [Central-Electronics] 10B  Mod
To: <telmore1964 at yahoo.com>,  <central-electronics at mailman.qth.net>
Message-ID:  <164E563ACBB541BA9AD5B9BF38C22909 at DesktopVista>
Content-Type:  text/plain; format=flowed; charset="iso-8859-1";
reply-type=original

Tom,

I believe that Tony  Vitale's "Cheap and easy SSB" transmitter used a 
12AU7 where the 10a, 10b,  20a used a 6U8. Maybe the very early 10's used 
the 
12AU7. I have a copy of  the schematic of the w2ewl special, but not handy. 
While looking for it, I  uncovered a bunch of other stuff. Maybe the group 
will find this stuff  interesting. See  below,
Jim
WD5JKO

http://www.ac6v.com/73.htm

Tony Vitale  W2EWL who lived in Denille NJ wrote an article in CQ in the 
early1950's  entitled "Cheap and Easy Sideband".  It was a 9 Mhz USB 
phasing  
generator tweaked for optimum suppression on LSB and an ARC-5 used as a 5  
Mhz VFO.  It summed the 9 Mhz USB signal and 5 Mhz VFO to work on 20  
meters. 
Sum mixing does not invert the USB signal.  It used  difference mixing to 
work on 75 Meters, causing the USB signal to be  inverted to LSB.  At this 
time commercial SSB rigs were virtually non  existent.  Shortly after this 
article was published, Wes Schaum &  Joe Batchelor formed Central 
Electronics 
and utilized a similar design to  make the 10A, 10B, & 20A. The few hams 
using "Ducktalk" had only the  capability of USB on 20 meters and LSB on 75 
meters.  Thus the  convention was set.  When other rigs like the 10A, 10B, 
& 
20A  came along, they followed the precedent that had been set by the 
"Cheap  
and Easy Sideband" article by Tony Vitale.  I met Tony in 1975 when I  
worked 
for Cessna. Tony retired in the late '70's and died in the mid  80's.

http://www.qsl.net/k5bcq/Lorne/w2ewlside.jpg
http://www.qsl.net/k5bcq/Lorne/w2ewlfront.jpg

here  is another one built:
http://www.ohio.net/~ka8wtk/458/458.htm

Some  more history:

Single sideband This is not to suggest that no amateurs  were developing 
the 
art in the SSB field, still a controversial  area.

Tony Vitale WZEWL, made many a convert with his cheap and Easy  S.S.B.'' 
('March 1956) an ingenious phasing-type exciter built in and  around a 
surplus BC-458 transmitter.

Murray Crosby, WZXSY,  described his ''product detector'' in May, l 956 and 
made it impossible  for anyone during the following years to peddle a 
sideband receiver that  didn't have something labeled a ''product detector."

In September 1957  Howard Wright, MQPNB, one of the early sidewinders 
described the "Third  Method of S.S.B. Generation" a system primarily of 
academic  interest.

In 1960 the 7360 beam-deflection balanced-modulator be was  introduced and 
in 
the same year Joe Galeski WWIMP described his three-tube  complete filter 
sideband transmitter which certainly must have set some  kind of a record 
for 
minimums.

By 1960 the pattern of  linear-amplifier design was firmly established; 
tetrodes operation ABl for  high-sensitivity applications, or grounded-grid 
Class B triodes when 30 to  100 watts of drive was available.
Historical articles from  the 
1964  issues of QST.  Submitted by Jim Linn, WB8RRR

-----  Original Message ----- 
From: "Thomas Elmore"  <telmore1964 at yahoo.com>
To:  <central-electronics at mailman.qth.net>
Sent: Saturday, November 07,  2009 3:50 PM
Subject: [Central-Electronics] 10B Mod

> Does  anyone know if there was a mod to change the 6U8 tube in the 10B 
out 
>  to a 12AU7?  Mine is set up that way and it almost looks  factory?
>
>
>
>
> Thanks
>  -Tom
>
>
>
>  ______________________________________________________________
>  Central-Electronics mailing list
> Home:  http://mailman.qth.net/mailman/listinfo/central-electronics
> Help:  http://mailman.qth.net/mmfaq.htm
> Post:  mailto:Central-Electronics at mailman.qth.net
>
> This list hosted  by: http://www.qsl.net
> Please help support this email list:  http://www.qsl.net/donate.html  

------------------------------

Message: 2
Date: Sun,  8 Nov 2009 11:57:13 -0800
From: "k7fm"  <k7fm at teleport.com>
Subject: Re: [Central-Electronics] 10B Mod
To:  "Jim Candela" <jcandela at prodigy.net>,  <telmore1964 at yahoo.com>,
<central-electronics at mailman.qth.net>
Message-ID:  <E890F41240C045468E37A9FBAF423571 at COLIN>
Content-Type: text/plain;  format=flowed; charset="iso-8859-1";
reply-type=original

I think the early CE exciters used a 12AU7 for the  9 mc (it was still mc 
in 
those days) oscillator.  That was replaced  by a 6U8, and stability of the 
crystal oscillator was improved.   There was an article in CQ on 
stabilizing 
the early 12AU7 crystal  oscillator.

73,  Colin  K7FM  

------------------------------

_______________________________________________
Central-Electronics  mailing  list
Central-Electronics at mailman.qth.net
http://mailman.qth.net/mailman/listinfo/central-electronics

End  of Central-Electronics Digest, Vol 67, Issue  5
**************************************************