QRP Projects, 80M (low parts) Transmitter (fwd)

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From: Adam O'Donnell (adam@philadelphia.libertynet.org)
Date: Fri Sep 29 1995 - 19:38:33 EDT


I just thought that you guys may be interested in this.

>
> > 80 Meter (Low parts) Transmitter (from Jeffrey Herman, NH6IL)
> >
> > --------------------------------------------------------------------
> > Gang,
> >
> > If there was a contest to come up with a xmtr containing as few
> > parts as possible, this would be the winner: 10 parts if you include
> > the key, battery, and antenna!
> >
> > In the CODE/NO-CODE debate on r.r.a.policy some pro-coders will
> > mention the simplicity of CW xmtrs as opposed to those of other
> > modes; this circuit really drives that point home (that's why I'm
> > posting this on .policy)
> >
> > On r.r.a.misc we've heard talk about how costly ham gear is today -
> > all this rig will cost you is the effort to find an old color TV
> > chassis - that's the parts source for all my QRP transmitters (and
> > this is why I'm also posting this on .misc).
> >
> > Normally I post these xmtrs only on r.r.a.homebrew and on the QRP
> > mailgroup; so if you've missed the first dozen xmtr circuits email
> > me and I'll send them off to you.
> >
> > I built this for 80M only because I've got so many 3579 kHz crystals
> > from old TV sets, but this can be used on any HF band - just choose
> > L and C to resonant at the crystal frequency.
> >
> > For peace of mind you might want to add a bandpass filter to the
> > output.
> >
> > --------------------------------*---------*--------*----||---ANT
> > | | | | 10pf
> > | | | |
> > - | ) ---
> > XTAL | ) --- C
> > - | ) L |
> > | | / c ) |
> > *----------------------------|/ | |
> > | b |\ | |
> > | 2N2188 \ e *---------
> > / or any PNP | |
> > \ 100K that'll work | |
> > / GND |
> > \ |
> > | |
> > *-----------------------------------------*
> > | |
> > | |
> > | ---
> > | --- .01uf
> > | |
> > ---------*KEY*----*1 to 4 volts +*--------*
> > |
> > |
> > GND
> >
> > Again, choose L&C to resonant at the desired frequency; one of the
> > two should be adjustable. I got both from the chromatic board of a
> > TV - both were sitting next to the 3579 kc xtal; easy, huh? I didn't
> > use a 2N2188 transistor; rather, I used a x-sistor right off the
> > video board (of the TV).
> >
> > So, don't you dare buy one component for this - just dig through
> > your junk box (or your neighbor's trash for an old TV). With a good
> > antenna (those are the magic words in QRP work) this little
> > peanut-whistle will provide hours of pleasurable QSO's.
> >
> > Oh, 3579 kc has become a national QRP frequency due to the easy
> > avail- ability of these crystals.
> >
> > .... .- ...- . ..-. ..- -.
> >
> > Jeff, NH6IL
> >
> > Jeffrey Herman, University of Hawaii Mathematics, jherman@Hawaii.Edu
> >
> > --------------------------------------------------------------------
> > Last Modified Monday, December 12, 1994 - Lou Williams
> > (nsyslaw@acs.ncsu.edu, KE4ARM)
>

72

-- 
Adam O'Donnell, N3RCS
Amsat:  N3RCS@AMSAT.ORG
Internet:  ADAM@LIBERTYNET.ORG

"I want to know how God created this world. I am not interested in this or that phenomenon. I want to know His thoughts, the rest are details."

-- Albert Einstein


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