Posts Tagged ‘tube type transmitters’

SPECIAL DEAL ON 6V6 MC 80 M PASTIME PROJECTS TRANSMITTER KIT

August 9, 2016

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 think there are little green men!

October 4, 2014

I got into the Radio Amateur business way back when vacuum tubes were king. I read and re-read
the “Radio Amateur Handbooks” put out by the ARRL (Amateur Radio Relay League) – They are still
publishing them – from cover to cover. I even read the technical stuff. Later, when I got into
the hobby and received the monthly QST Magazine, I would speed read each technical article to
discover what technical break-through the author found to advance the circuitry another step.

I could draw a transmitter schematic completely from memory. I passed the Commercial License
examination without studying. It was just interesting stuff to me. I really understood vacuum
tubes!

Fortunately, I was still young and interested enough when transistors came along to grasp how
they functioned. This was about the same time I started college and flying saucers were in the
news a lot. I remember thinking, “Maybe they are right! The transistor was such a quantum leap
from the vacuum tube they learned the technology by reverse engineering the gadgets found aboard
the wrecked flying saucer!” To me that was just an interesting thought; to others, it became
an obsession.

Right now I am redesigning my regenerative receiver. And I have substituted toroid coils for the
old large plug in coil forms. The advantages of toroid coils are another example of a quantum
leap in technology.

Thanks to all you wonderful engineers out there for bringing us so far forward in a relatively
short time! Or should I be thanking the Little Green Men? 73 and enjoy building something.
Glenn Brown NN8G for Pastime Projects..

and

Pastime Projects Vintage style 6V6 Tube Type CW Transmitter – Another reveiw.

February 8, 2014

We would like to thank Amateur Radio Operator WB0FDJ Clarence for his writeup in eHamNet of our slat board
vintage style 6V6 CW 80/40 meter CW kit. See http://www.eham.net/reviews/detail/10299. It is reviews like
this that bring others to our web page http://www.pastimeprojects.com . Thanks Clarence and happy operating!
Glenn pastimeproject(at)yahoo.com

Correction to www.pastimeprojects.com home page

December 13, 2013

We recently discovered that the PDF file for the Pastime Projects 5 watt dummy load instruction manual was not coming up when we clicked on the button on the home page.
Today we corrected that. Now you can see the entire manual at no charge. Please let us know if it doesnt work.
email pastimeprojects AT yahoo.com.
We have two of the prototype kits of the 6V6MC 40 meter
crystal controlled cw transmitter left in stock. These are the ones we fully assembled here and tested. These use a metal chassis which was prepared by hand. The producton kits use a commercial water jet prepared chassis and these are true do it yourself kits. If you are ready to order the actual kits, please email us. We are close enough to
production to start considering orders.
73 Glenn http://www.pastimeprojects.com

Prototype Pastime Projects Metal Chassis 6V6/6L6 transmitter on sale.

June 30, 2013

Assembled and Tested!

Assembled and Tested!


The new Pastime Projects 6V6 transmitter kit has been built and tested as a prototype. The difference between the prototype and the production models is the chassis. The metal chassis on the prototypes was machined by hand. The production chassis are cut in a high pressure water jet precision tooling machine. The prototypes were assembled and tested here and look and work great! Allow us a little time to get these out the door to you. There was a total of
7 or 8, and when they ship we will start packing the production kits with parts, manuals, and instruction manuals. This design is based on conventional handbook
designs of the late 1950’s and 1960’s. Operating on 40 meters. 3 to 10 watts of cw output into 50 ohms..
COME AND GET’EM Glenn for Pastime Projects
http://www.pastimeprojects.com

Use of light bulb dummy loads in Vintage Amateur Radios

May 29, 2013

We recently reworked a Johnson Viking Adventurer CW transmitter and an EICO 723 transmitter, both manufactured in the 1960’s. They can be seen at http://www.pastimeprojects.com on the Special Sales page.
A common failure of these transmitters was the power transformers.
They can overheat from current draw in excess of specified limits. This is often caused by not tuning the transmitter quickly or by mistuning and operating out of resonance.
Back in the 1950 and 1960’s we often used an incandescent light bulb for a load. It was cheap, and the resistance was close to 50 ohms or so required for the output of the transmitter. Tube type transmitters are a lot more forgiving from misstuning than solid state types. Never use a light bulb for a dummy load on your new
solid state rig! Choose a light bulb that has a wattage higher than the expected output of your transmitter. Watching the light bulb as you quickly tune to resonance will get you properly tuned without
too much time passing. Brightness is an indicator of power out. After tuning make sure you are not exceeding the recommended current draw. If you are, decrease the antenna coupling until you
are lower than maximum recommended power. Remember the old transmitter were rated in power input, now output. Output will always be lower. Input is plate current times plate voltage. This discussion is very simplified. Stay away from high voltage and high r.f wires. It’s hoped that it will help you see how to tune your boatanchor radio. Look for more detail in our newsletters and we may put out a video on disc or YouTube.
Questions are always welcome. Glenn for Pastime Projects.
pastimeprojects(at)yahoo(dot)com..