Archive for April, 2012

Plug-in Coil forms for the Radio Builder

April 30, 2012

“Back in the days” home built radio receivers and transmitters often used plug in coils. Plug in coils were used with variable capacitors to create an “L-C” circuit (L being the inductance and C being the capacitance).  The coil-capacitor combination was connected in parallel to tune the cicuit. To narrow the range even further a second variable capacitor would be wired in parallel with the LC circuit.  This  second variable would be of low value and would change the resonant frequency of the circuit a very small amount. It would, in effect be the “Band Spread” of the tuning circuit. One more obvious example was the wonderful old Hallicrafters Recievers. They had the main tuning dial on the left, and a bandspread dial on the right.

Radio amateurs are interested in very small portions of the radio spectrum. These small frequency allocations were best tuned so that the whole CW or Speech portion of the Amateur band would cover the entire swing of the variable tuning capacitor.  By narowing the coverage,  hams could spread out the signals.  While many receivers used a complex switch to change frequencies.  The plug in coil was simpler, less costly, and a favorite amoung our predecessors.

Pastime Projects (www.pastimeprojects.com) introduced new plug in coil forms in October of 2010.  The dimensions and construction of our coils is shown in the attached sketch.

The Pastme Projects coil form is available either glued or unglued. The joint is edge glued between the coil form and the octal base. The glue used in the factory is Loctite Stik n’ Seal Non-Toxic adhesive manufactured by Henkel Corp of Avon Ohio  www.loctiteproducts.com

While the coil form of old may have used 4 pin or 5 pin sockets, these have become scarce.  The use of the octal base makes more sense and give us some choices in the amout of taps and/or coils we can combine on one form.  An obvious disadvantage of the octal socket is more friction in inserting or removing the coil from the base.  We have found that the extra unused pins can be carefully cut off.  We have easily removed every other pin and ended up with a 4 pin socket which is much easier to work with.  It still allows the allignment of the coil into the correct pins in the base because of the keyed center pin on octal bases.  You can choose how many pins you need on your coil for your project. 

 

Why not include plug in coil forms in your next project?  Vry 73 es bcnu Glenn for Pastime Projects.

Vintage Ham Radio Crystals and a new web page

April 26, 2012

www.pastimeprojects.com has so many vintage crystals for sale.  These include the old round Blily Crystals. Some have the original boxes. We have a few of the old big cyrstals as used in the mighty BC-610 of World War 2 era. Many many surplus crystals including the FT 243 styles. These are stocked mostly to accomodate our vintage 6V6 home brew transmitter kits, but they are available to anyone. Some are original sealed cases. We have some that are new crystals inserted and tested in the old FT 243 cases. 

Right now we have highlighted some of the 80 meter crystals on our new web page. Please check it out at www.pastimeprojects.com and click on Crystals page button.

Thanks!

Goodbye ear-rings Hello new directions.

April 21, 2012

The ear rings that were offered for sale on our www.pastimeprojects.com have been discontinued.  They were hand made of electronic parts and were first  introduced at hamfests several years ago. They sold well at the hamfests and we will continue to sell them. We have even seen a few others offer jewelry of a similar kind at some shows.  The idea was good but just not a big seller on our web pages.  Several other ideas for the web are in the works. These include a changing message in Code for code practice, a high quality top condition auction of those things of yesteryear we hold so dearly.  Ideas include scooters, model airplanes, motorcycles, gas engines old small implements, folk art whirligigs, carvings and what ever…  Please write you ideas directly to us at pastimeprojects[at]yahoo.com .  Best regards  Glenn NN8G

eBay sales suspended

April 15, 2012

On Thursday April 12 we called eBay with a question about new seller rules. The question concerned what I perceived as a new necessity that sellers now open access – for a considerable amount – into a business bank account to eBay. This brought up considerable questions on our part.  The eBay associate was courteous and seem to understand our concerns. The concerns were forwarded to others at eBay.  eBay has always been responsive to our concerns, and we have no reason to think this situation will be any different.

Until we hear back from eBay,  we have decided against selling on eBay.. The question concerns protection of our company finances and is serious enough to await satisfactory resolution before considering whether to resume selling.

Please consider purchasing directly from our www.pastimeprojects.com web site. We offer good values, and flexibility in ways to pay. As  announced recently we also welcome inquiries from overseas customers.  Questions? Please contact us through pastimeprojects@yahoo.com  .Be sure to include a subject so we know how to follow up.    Best regards Glenn NN8G

Vacation Over

April 11, 2012

Spring brings a new season to Pastime Projects. We will be advertising our products on eBay this month.  There will be a link to eBay from the www.pastimeprojects.com web home page so you can always compare eBay descriptions and pricing with the web site.  If you are ever in doubt about the best way to purchase, just email us at pastimeprojects(at)yahoo.com for our help.  You may get a special value through the email system.  We can also handle questions on methods of payment,  postage costs, overseas shipments, combined orders and so on..  The ‘store’ is open.  Please “give us a call”.  Glenn