Crystal Radio Supply

Show in the center of the photograph is a high quality Spider Web Coil Form. Made from High Impact R21 ABS.

Do not mistake these forms for the hard board and particle board  forms sold elcewhere.  These are tough well built  high quality forms with good insulation factors and are sure to please.

Coil Form Specifications                                                                            Tail of two Coils

Material High Impact R21 ABS                        The Coil on the left was wound with 54 turns of 175/46 Litz Wire

Width .093 inches                                               aprox.       240UH      wire used about 46 feet

                                                                                Q=300 @790KHZ

Inside Diameter 1.875 inches

outside Diameter 4.25 inches                          The Coil on the Right was wound with 51 turns of 24 enamel

Total Hight  5.3125 inches                                 aprox.       240UH     wire used about 44 feet

                                                                                 Q=140 @790KHZ

 #6 mounting holes

 This is a high quality Spider Web Coil Form. Made from High Impact R21 ABS.

Other that the size this form is the same as the Larger Spiderform-1 It was made for the  smaller gage 40/44 litz wire and is good for up to 360 Micro Henry with that smaller gage wire.

Do not mistake these forms for the hard board and particle board  forms sold elcewhere.  These are tough well built  high quality forms with good insulation factors and are sure to please.

Coil Form Specifications   

Material High Impact R21 ABS

Width .093 inches 

Inside Diameter 1.75 inches

outside Diameter 3.6875 inches 

Total Hight  4.625 inches  

 #6 mounting holes 

This 330 Micro Henry Coil is made from #22 enamel wire wound  on a tough cardboad form.

This Coil measures 2 1/8" in diameter and is about 4" long.

The entire Coil is Double Dipped in Polyurthane.(dipped allowed to dry and then dipped a second time)

Quality Factor is  over 140 @ 790 KHZ

At this price  how much are you saving by winding your own coil ?

Universal 330 Micro-Henry Crystal Radio Coil. (+/-5uh)

This Coil has ten take off loops plus two end leads. This makes 12 potential take off points!

made from #22 enamel wire wound  on a tough cardboad form.

This Coil measures 2 1/8" in diameter and is about 4" long.

The entire Coil is Double Dipped in Polyurthane.(dipped allowed to dry and then dipped a second time)

Quality Factor is  over 140 @ 790 KHZ

This Hi Q Crystal Radio Coil is supplied with mounting clamps. It measures about 3.25 inches long and is wound on a 3/8 inch diameter ferrite rod with 175/46 litz wire.

Coil has been double dipped in polyurthane (dipped allowed to dry and then dipped a second time.)

Q Factor over 400 @790 KHZ 

Miniture 470 Micro Henry Coil

Measures Just 5/8 inches wide and 2 5/32 inches long.

For an econo Crystal Set use with our Two-Gang Miniture Variable Capacitor Part # MC2  with both sections in