Archive for July, 2016

“LookMa” Oscillator Kit available without 12K5 Tube for savings.

July 28, 2016

The price of our little 12K5 40 meter oscillator kit recently increased due to the scarcity and
price increase to us for 12K5 “space charge” tubes. The tube, of course, has long been out of
production. It has the unique property of being able to function at 12 volts dc ON THE PLATE.
Due to this very low dc power, the output power is a fraction of a watt, compared to, for instance,
a higher voltage tube such as a 6aq5 which can product 2 to 4+ watts on higher voltage DC inputs.
(Tubes are not interchangeable in the circuit. – Check your tube manual). The 12K5 tubes are advertised
on eBay as well as many other sources on the internet. Just do a search for 12K5 Tubes.
We will offer our kit for $35.00 less the tube, plus $5.00 S&H in the US.
This kit will not produce enough signal to contact other radio amateurs, but it is a learning tool,
and can be used for code practice within the shack. Very best regards Glenn W8JZI for
http://www.pastimeprojects.com

"LOOKMA" QRP oscillator kit returns

“LOOKMA” QRP oscillator kit returns

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20 Meter Version Pastime Projects “Remember When” 6V6 Transmitter Kit Dropped

July 23, 2016

Further experiments with the 6V6 “Remember When” Pastime Projects 20 meter version of the Handbook published “Slat Board” wood chassis 40/80 meter CW Transmitter has been halted. Seems the 1940 Amateur Radio do-it-yourselves guys
knew what we had to discover ourselves. Instabilities that begin to show themselves on 80 and 40 meters become game changers on 20 meters. While the crystal seemed stable and chirp free with careful adjustment on the bench while transmitting into a dummy load, connecting to an antenna changed the situation. Even with a carefully tuned 50 ohm match, the capacitor value became sensitive to close-by variables. In our own terms, this means if my hand was
within 12 inches or so of the capacitor, resonance was lost or greatly degraded. It quit working or went off
frequency! Lesson learned. (1) Wood chassis do not shield coils and capacitors from surrounding effects. (2) Instabilities in RF circuits become worse at higher frequencies. (3) Better respect your Grandpa’s designs! They
knew what they were doing.. (4) Unless you plan to operate ten feet away from your slat board 6V6 transmitter, twenty meters on the Pastime Projects “Remember When” 6V6 Transmitter is not going to work.
Got to keep your sense of humor in this business and, for goodness sake, don’t EVER quit experimenting!

By the way, the origin of the “Remember When” name for our kit is explained on page two of our instruction manual.

Very best wishes and don’t let that soldering iron get cold! Glenn for pastimeprojects(at)yahoo(dot)com.rem kit a (2)

20 meters on the “Remember When” Pastime Projects 6v6 Transmitter Kit

July 22, 2016
SAMSUNG CAMERA PICTURES

SAMSUNG CAMERA PICTURES

We have been experimenting with a 20 meter set-up for the “Remember When” 1948 era Pastime Projects 6V6 Transmitter Kit which we have been manufacturing and selling for ten years.  On the bench it appears stable, clean, and ready to go.  We have not made on the air contacts as of today.  The information is being added to our manual.  If you own a Pastime Projects 6V6 transmitter please email us for more free information.  More changes are coming!  You are going to love our next announcements. Stay tuned!

PS  Don’t You love the vintage B&W Grid Dip Meter in the picture background?  Yes, it works!   73  dear friends —  Glenn  W8JZI Pastime Projects.