“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

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
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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.

12K5 OSCILLATOR KIT PRICE INCREASE

June 8, 2016

After 10 years of production our little 40 meter do it yourself code practice oscillator kit faces a price increase.  We recently looked at our costs in today’s market as compared to what we paid in 2006.  The increase is effective immediately. You will still get the same pre-wound coil, a new qrp style crystal, and the detailed instruction manual we have strived to improve over the years.  While this is considered a “transmitter” kit, we very
plainly describe its communication ability as “most likely won’t be heard next door”. You kit builders know that it’s still a thrill to follow instructions and build something yourself.

Remember When QRP 40 M transmitter

Happy Building!  73 Glenn for Pastime Projects   pastimeprojects(at)yahoo(dot)com

 

 

 

 

 

 

 

Pastime Projects Metal Chassis Transmitter Kit added value.

February 27, 2016

The Pastime Projects 6V6/6L6 vacuum tube HF transmitter kit has been updated with coils and instructions for 80 meter CW operation.  This is in addition to the 40 meter operation previously included.

The operation change from 40 to 80 meters requires only a change in the plug in coil and a change in the transmitting crystal.  Simple and quick.

The manual now includes the drilling and winding instructions for both frequencies.  It has been our practice to include the coil form and wire for winding the coil in the kit.  Now both coils, one for 40 and one for 80 will be included in the package.  Of course, the builder will  have to wind the coils, but that’s half the fun!

Already purchased our kit?  Just write and we will send the updated version at a no charge other than postage and handling.    73  Glenn  for  pastimeprojects@yahoo.com

6V6 Vintage Kit as QRP Transmitter

December 22, 2015

Today we tested our “Remember When” Transmitter with 135 volts on the plate.  This was done at the request of an amateur who had recently built a power supply with 135 volts out at 50ma.  He was wondering what kind of power output could he expect from our Pastime Projects kit at this voltage.

Rather that interpret tube characteristics,  I went to the shop and set up the test.  There are some photos attached. I found that we could expect about one watt output into a 50 ohm load with 135 volts on the plate. This is definitely QRP (low power) operation!

He had experience with QRP operation, so the result was not unexpected. Our power supply kit runs about 200 volts dc and provides about 2 watts out. We recommend no more that 300 volts on our 6v6 kits.  The 6v6 will provide 10 to 14 watts output in certain classes of operation and higher levels of plate voltage.

Hope the pictures show the story.  We used a new imported 6V6 such as we sell on http://www.pastimeprojects.com. We used a new International Crystal made to old specifications (we also stock a few). Questions ?  contact me at pastimeprojects (at) yahoo (dot) com.  73  Glenn

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Pastime Projects High Voltage Power Supplies

September 3, 2015

Pastime Projects (www.pastimeprojects.com) manufactures amateur radio kits. Two of our most favorite are the “Remember When” slat board 6V6 kit which was featured in the 1948 (and elsewhere) ARRL Amateur Radio Handbook. This simple transmitter used a 6V6 (or 6L6) vacuum tube on a chassis made of orange crate wood. It was designed for the amateur radio operator to send CW (code) on 80 or 40 meters.
Our more recent kit uses a metal chassis and an improved oscillator kit introduced in the 1960’s Handbooks. It was more stable, easier on crystals, and oscillated on 80, 40 and other bands by switching plug-in coils. Ours uses a 50 ohm link coupled output which matches today’s antennas, antenna tuners, low pass filters, and dummy loads.
These circuits, as first published, were often accompanied by a power supply design which used a 5 volt rectifier vacuum tube. We chose to use modern solid state silicon rectifiers instead. This eliminated the need for a 5 volt winding on the transformer, and the added heat, light, current demand, vacuum tube, tube socket and so
on associated with the rectifier tube.
The result is a simpler less costly power supply for you to build and enjoy. Best regards, Glenn Brown W8JZI for pastimeprojects.com

What is next at Pastime Projects?

July 5, 2015

Got an email from one of our customers wondering why we didn’t make the output on our 6V6/6L6
transmitter kit a pi-network instead of link output. Very good question! Probably one factor
in our decision was the cost of the change. Variable capacitors are expensive. The chassis size
would probably have to be larger also. But, these are not big issues. He is probably right; we
should revisit the pi-output design.
Some of the projects underway now include:
1. Regenerative receiver with tube(s) and toroid coils – Short Wave design with capability
to tune ham radio cw, am, and ssb in a rudimentary fashion. Status at this time is a prototype
6 – 10 MHz model that is very promising. Needs to be simplified for easy duplication as a kit.
Current model runs on 12 volts dc. No project completion date set.
2. Our low pass filter design converted to PCB configuration. We have the tools but not
the talent or time to complete this task. Interested in volunteering your expertise in this
very basic board design?
3. Vacuum Tube T-R switch based on vintage Handbook designs for handling our transmitter/
receiver interconnection automatically transferring from transmit to receive mode. Well underway
with this project.
4. Simple receiver design, probably solid state, to allow reception of cw along with our
transmitters..

Any ideas or suggestions? Let me know. Glenn W8JZI(at)ARRL(dot)NET or go to contact us
page of http://www.pastimeprojects.com7.28.09 prod

Pastime Projects New PS-2 MC Power Supply Kit Now Shipping

June 25, 2015

Pastime Projects PS-2  MC Power Supply Kit

Pastime Projects PS-2 MC Power Supply Kit


The new Pastime Projects PS-2 Power Supply Kit, designed for use with the Pastime Projects 6V6/6L6 MC Transmitter kits is now in production. This is a high voltage power supply kit built up on an aluminum chassis.
The instruction manual includes all hole drilling locations and descriptions, complete parts assembly and wiring instructions and step-by-step help all the way. The voltages present in this kit do require experience and safety awareness of working with high voltage. Drilling and measuring skills, soldering, assembly and ability to follow instructions is also required. Many illustrations of all aspects of this kit build are included in the 13 page manual.
Illustration from PS-2 Manual

Illustration from PS-2 Manual

Please visit http://www.pastimeprojects.com for more details, specifications, and ordering information. 73 Glenn W8JZI

Power Output of the New Pastime Projects 6V6/6L6 MC Transmitter Kit

May 28, 2015
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Here is more info on the power output of the little 6V6/6L6 MC Kit.

Test Frequency was 7.042 MHz with 6L6MGC (China) vacuum tube. Measured into a 50 ohm dummy load. Wattmeter used was a Oak Hills WM-2 . New prototype Pastime Projects PP PS MC Power Supply running approximately 200 VDC..(Pictured)

Under these conditions, power output was approximately 2.2 watts. (Results on 3.515 and 3.580 were about the same using an 80 meter plug in coil and 80 meter crystal) .Switching back to the 40 meter coil and crystal, we tested the kit using a Laboratory Grade regulated power supply with the following results:  200 VDC SETTING EQUALLED APPROX 2 3/4 WATTS OUTPUT.  250 VDC SETTING EQUALLED APPROX 4 3/4 WATTS, 300 VDC SETTING RESULTED IN 7 1/2 WATTS, AND  350 VDC EQUALLED 10 WATTS. (6L6MGC)

The New prototype Pastime Projects Power Supply modified  provided 9 1/4 watts output.  This modification is not available in production at this time. The results of your set up may vary from the above results.

73 Glenn Brown    www.pastimeprojects.com