The new “Pastime Projects” Alham VT-1 Power Supply Kit is being prepared for shipment.
It includes a tube type rectifier as was used back in the late 1940’s and 1950’s. It
has an output of about 200 DC Volts – same as the current power supply which uses modern
solid state diodes for the rectifiers.
It’s design is simplified and uses a capacitor input style filtering circuit. The
circuit is similar in design to similar power supplies of the 1940-1950 era. There is
no filter choke in the circuit. In tests, we see no degradation in performance, but see
an advantage is less weight to ship, and less cost.
The kit includes a Cinch-Jones style plug and matching socket to connect the power
supply to your transmitter. These add a sizeable cost to the kit, but it’s well worth the
The circuit uses a fuse in the line cord circuit, and red and green neon lights to
indicate when power and high voltage are on. The high voltage lamp dims slowly as the
high voltage drains through the bleeder resistor built into the circuit.
While no decision has been made, Pastime Projects may discontinue the original
solid state supply as acceptance of the new power supply builds.
We will accept payment of the VT-1 power supply kits early, or, just email us for
notification of the release. Watch http://www.pastimeprojects.com for more news. 73 Glenn for
The new “Pastime Projects” Alham VT-1 Power Supply Kit is being prepared for shipment.
The regenerative receiver kit is returning to the http://www.pastimeprojects.com catalogue of radio enthusiasts kits.
The design was redeveloped around the 40 meter ham band range. It receives AM foreign broadcast, cw, single side band with patience, and radio amateur AM stations. It is not recommended for use as a main receiver for radio amateur stations. Regen receivers tend to require careful tuning. They show more drift than commercial receivers.
But they are fun for beginners, short wave listeners, and experimenters. Our design now has been tested on the
3.5 MHz range, and 80 meter ham bands are being heard. The kit includes some unusual features. One is the use of
a “space charge” type tube that uses 12 volts on the plate as well as the filament. That means this receiver will be powered by your 12 volt DC power supply. The kit is somewhat difficult, but assembly, wiring,, and testing are explained in detail in the step by step manual that is included in the kit. Stay tuned for more! 73 Glenn for Pastime Projects (at) yahoo (dot) com.
A new coil for the Pastime Projects 6V6 MC transmitter kit (http://www.pastimeprojects.com/) has just been wound for the 30 meter amateur radio band. This was done at the request of an interested fellow radio amateur.
The instructions for winding the 30 meter coil will be added to the 6V6MC construction manual which is included with each new transmitter kit sold.
While not yet used on the air, the transmitter here was checked on an older service monitor, our current Kenwood Transceiver, using a variable DC power supply, a Oak Hills Research WM-2 QRP Wattmeter, and a MFJ-264 dummy load.
The crystal available was a little high (11.000 mHz) but we compensated in coil design for the difference. Amateur frequencies on 30 meters should fall at resonance with the variable capacitor at half scale.
The 6V6MC 30 sounded stable and not chirpy in our tests. Readings included output of 0.5 W @ 100VDC, 2.0 W @ 200VDC, 5.0 W @ 300VDC, and 8.5 W @ 350VDC.
We will watch for on the air results from our radio amateur friends as this is checked out from their stations. 73 Glenn W8JZI for pastimeprojects.
The prototype parts selection and acquisition is almost complete. Parts are ordered and stock supplies are being arranged in the shelves. The Amish have finished the first run of the wonderful oak slats and end blocks. The length of the new power supply is shorter than the old power supply. The weight will be less – a good thing when mailing! The power out is equal to or better than the original design. Again, we are staying pretty conservative with 2 or 3 watts out on both 40 and 80 meter cw.
This is a really nice piece of art and will look good in your old tube type ham radio shack. Now if you have purchased a “Look Ma” transmitter and or power supply from us in the last ten years, and you are interested in the new matching power supply, please contact us ASAP. We want to get these out and tested in the field, so now is your chance! We will make it worth your while one way or the other.. 73 Glenn W8JZI for http://www.pastimeprojects.com or pastimeprojects(at)yahoo(dot)com
Before today’s modern transceivers, radio amateurs used separate transmitters and receivers. They were usually very large, vacuum tube designs, developed a lot of heat, and were quite a bit more sensitive to drift, filtering, hum, and adjacent channel interference.
Many amateurs continue to “work” with these designs for many reasons. If you build a transmitter kit such as we offer on our web site http://www.pastimeprojects.com, you have to figure out how to connect it to a receiver and be able to share a common antenna.
It’s really fun to connect it with a ‘modern’ tube type receiver, such as the Collins, Hallicrafters, National, Drake and others. EF Johnson sold a automatic switching TR switch, model 250-39 which worked very well. Do a search on the internet for more information. There are come up for sale occasionally; be careful – the condition of older equipment is always a concern.
Pastime projects is working on a new TR switch for use between vacuum tube type transmitters and receivers. “New” is not the proper term, as our design will be very similar to a published design from the 1960’s. We have a couple prototypes on the bench. We also have a rebuilt Johnson Model for reference. Watch for introduction on our web page soon. As always, write if you have comments. 73 Glenn W8JZI http://www.pastimeprojects.com or pastimeprojects(at)yahoo(dot)com
Just a final thought: These designs use a vacuum tube as a switch and switching between a low to moderate powered tube type transtmitter and a vacuum tube type receiver is automatic. Makes for very smooth transition. This is not a mechanical relay system which requires manual switching…
Today we are offering a special on our pastime projects 6V6 MC 80 Kit. This kit includes a wound and tested
Output plug in coil tested on 80 meters in our shop. In addition, we will include a new 3.5795 crystal element assembled in a FT-243 or similar style vintage type crystal holder. These are assembled and tested here, both
on a communications monitor and in a completed 6V6MC 80 Kit. These crystals are performing well for us in the
lab here at Pastime Projects, especially using our QRP mode power supply at 200 volts. The crystals have been
tested at 350 VDC with good results, but we are not ready to warranty the crystals at this time. For a limited
time we will also offer free shipping within the US. Delivery may run a little longer depending on demand,
but we are starting to build stock in advance of orders. 73 best wishes Glenn Brown for http://www.pastimeprojects.com and pastimeprojects(at)yahoo(dot)com.
I have an aluminum chassis with some scratches on the surface. The usual methods of preparing the surface include sanding, etching, several methods of cleaning and final preparation of the surface using caustic materials and/or
primers and so on.
I liked the old timer radio chassis look of the 1940’s and 1950’s with the crinkled black finish. I also like the
“Radio Kit” approach of the 1960’s where the look went to cool “crinkle finish” variations in green-blue
shades of color.
For preparation I washed the chassis with warm soap and water, then wiped it dry with a very soft “bar towel”.
I made cardboard cutouts the size of the vacuum tube flanges. I purchased some double-sided tape and covered one
side of the cardboard cutouts with this tape. After trim, I located these on the metal chassis. Most of the other holes on the chassis were covered with AVERY #6733 “Color Coding Labels”. I have seen these used for pricing things at garage sales.
Many stores carry the “Rust-Oleum” Brand of spray paints. I found Rust-Oleum “Multicolored
results. Just be sure you spray outdoors and away from fires and flames.
This chassis prep progress will continue. Watch for future blogs.
Just remember, I am no expert, and simple share my ideas with you. This takes time, and would appreciate it if
you share with friends, just include a little note this was first seen on Pastime Projects R3tr0rad’s Blog page,
written by Glenn Brown in August 2016. Visit http://www.pastimeprojects.com and hit “Contact Us” or simply mail
pastimeprojects(at)yahoo(dot)com with your thoughts. 73 Glenn
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
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.
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.