[HomeBrew] Projects

[Michael Tauson]

Let's see ... 

The shaking in my hands has gotten to the point that doing much of anything
can get exciting (Soldering shouldn't include things like slinging it about
... or so I'm told.) so I’m working on a set of Waldos to help me build.
Once they're in place, I have a number of projects to get back to ranging
from rehabilitating command sets (and re-converting already converted ones)
to building 1930s breadboard transmitters and the occasional receiver.  I
have an SX-24 that will be getting a regenerative preselector and an HRO so
1930s period receiving isn't a major issue.  OTOH, regens are fun to build
and experiment with.  The transmitters will generally be for 80 & 40m CW
with several different types of oscillators (crystal & VFO) and power
levels.  

One transmitter, however, is slightly different.  SSB was a known technology
in the 30s (Robert Moore's articles in R-9 in 1933 & '34 plus AT&T's carrier
systems if nothing else) and hams had the tech to use it available.  The
only problem was that during the Depression Era, that tech was expensive and
not a lot of folks had the wherewithal to build the equipment.  (That's how
I was told, anyway.)  The idea then is to build a 20 & 10m SSB rig using
1930s tech in a manner consistent with the era with some concessions to
current signal standards.  40m was CW only at the time and 15m didn't exist
as a ham band until after the war.  (Nor did the WARC bands but that's kind
of a given.)  160 & 80m I believe may not be good for getting far off the
islands given antenna issues although adding 80m is a possibility.  

The plan so far is to use a LF/MF VFO with several crystal oscillators,
mixers and multipliers for tuning and band setting. The sideband generator
would also be somewhere down low but I haven't decided where yet.  85 KC is
a possibility since I can get away with BC-453 components without being too
far off the mark.  (The original design is from the late 1930s so fits at
least that far.)  I may wind up using the IF cans from another 1930s product
(BC-348) to provide a higher frequency for mixing with the VFO and for band
setting.  One part I haven't decided on is what part of 10m I want to cover
since as sketched at present, I can only tune across a 500 KC segment of any
band.  For 80 & 20, this is plenty but for 10m it's not quite adequate.  

Sticking with the tech available will make this complex and the methods I am
looking at won't help any but it will be an interesting project that will
require some interesting crystal grinding and tuning.  Since the preferred
method of construction is breadboard, it will also offer a set of headaches
regarding shielding and isolation but that's half the fun of it.  

So much fun, so few pineapples.

Best regards,
 
Michael, WH7HG, A&P 1803851 Ph: 1-866-733-0218
I live with a maniac at home, my other me.
http://www.nationalmssociety.org/chapters/NTH/index.aspx
http://wh7hg.blogspot.com/
http://kludges-other-blog.blogspot.com
Hiki Nô!