[Central-Electronics] 10B Mod

[Jim Candela]

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