We are a reliable source for many of your litz wire and crystal radio part needs. Since 2008, we've sold more than 19,000 orders with excellent customer feedback. Please visit our eBay Store at mkmak222_Litz Wire to see what is currently available.

We have over a hundred types of litz wire in stock. They contain 5 to 1725 strands of AWG 48 to 28 (0.03 mm to 0.32 mm) wire. The litz wire's equivalent AWG are from AWG 36 to AWG 4.

If you don’t see a particular type of litz wire that you're interested in, please contact us so that we can help arrange a custom order. We can usually have these delivered in three weeks. Large orders may be purchased at the wholesale price.

Most orders will be shipped within one day. The small amount of wire will be coiled on 6” or 7” diameter paper spool to prevent the destruction of the litz wire structure. Larger amounts will be coiled on the original plastic spool.

Note: For avoid damage the structure of the small Litz wire, please observe photo “How to un-coil litz wire from the spool" on my eBay List.

When winding a coil, in order to smoothly un-coil the Litz wire from the paper spool, the simple method is: Vertically fix a 1/4-inch diameter screw rod on a flat plate, and then put paper spool into screw rod flat. When you pull out the litz wire from the paper spool, the paper spool can rotate freely on the screw rod, and the litz wire will not be twisted and knotted.

You only need an electrical solder iron to solder the litz wire. When you heat the end of litz wire, the polyester yarn insulation will be melted and recoiled, the polyurethane insulation that covers on copper strands wire will be completely volatilized, and the copper wire will be tinning.

Here you are bidding on a special nickel-zinc ferrite toroid. The size is 37 X 23 X 7 mm, use Ni-Zn R40C1 material. Made in China.

The Products made by Ni-Zn R40C1 material are design to use for shortwave transmitter power distribution, power combining, impedance transformation, power output, power chokes, short wave antenna barron and so on; in high frequency applications they have low loss characteristics.

The photo above shows the characteristics of this R40C1 ferrite toroid. Its applied frequency is up to 50 MHz.

The R40C1 Ferrite Toroids made by special formula. We don’t know why this type of Ferrite Toroid has very high Q when wind the coils for LW, MW and part of the SW. Even though the material R40C is very close to R40C1, the Q is much lower with the same coil spec (usually not easy to reach 700Q in MW). I introduce the R40C1 here because the Crystal Radio enthusiast always wants to make coils that have high Q and want them as high as possible. The coils I wound with R40C1, are able to get 900 Q at 3 MHz.

For sure the R40C1 can use for many other applications. This field is waiting for discover by amateurs.

Use this R40C1 37 X 23 X 7 mm ferrite toroid and litz wire to make coils will give you a big surprise! It can get very high Q value and let the radio circuits significantly increase the selectivity and sensitivity.

I stick two 37 X 23 X 7 mm toroids together with a layer of Teflon membrane (PTFE). It is equivalent to 37 X 23 X 14 mm and intertwines 60 turns of 250/AWG 46 Litz wire (the wire length is 16 feet). Inductance of this coil is about 223 µh.

The results measured from a HP 4342A Q meter are:

530 KHz          1305 Q
555 KHz          1317 Q
605 KHz          1328 Q
705 KHz          1335 Q
805 KHz          1321 Q
905 KHz          1293 Q
1005 KHz        1247 Q
1105 KHz        1203 Q
1205 KHz        1146 Q
1305 KHz        1098 Q
1405 KHz        1051 Q
1505 KHz        1004 Q
1605 KHz        950 Q

In 1605 KHz still has 950 Q.

Then I thought of Ben Tongue's Contra Wound Coil. I intertwine two coils opposite direction; each one is 29 turns 250/AWG 46 Litz wire (the wire length is 16 feet). Inductance is 205 µh when two coils is series connection (29 + 29 turns), and 63 µh when two coils is in parallel (29 turns but equivalent with the 500/AWG 46 Litz wire). Measurement results are:

Series connection                Parallel connection

545 KHz    1257 Q                  ____
555 KHz    1265 Q                  ____
605 KHz    1290 Q                  ____
705 KHz    1322 Q                  ____
805 KHz    1331 Q                  ____
905 KHz    1324 Q                  ____
1005 KHz  1299 Q                  1085 KHz   1424 Q
1105 KHz  1274 Q                  1105 KHz   1426 Q
1205 KHz  1241 Q                  1205 KHz   1425 Q
1305 KHz  1205 Q                  1305 KHz   1416 Q
1405 KHz  1168 Q                  1405 KHz   1405 Q
1505 KHz  1129 Q                  1505 KHz   1389 Q
1605 KHz  1090 Q                  1605 KHz   1371 Q
____                                        1705 KHz   1351 Q
____                                        1805 KHz   1331 Q
____                                        1905 KHz   1308 Q
____                                        2005 KHz   1283 Q
____                                        2105 KHz   1262 Q
____                                        2205 KHz   1236 Q
____                                        2305 KHz   1211 Q
____                                        2405 KHz   1184 Q
____                                        2505 KHz   1162 Q

Up to 2.5 MHz still can get 1162 Q.

An amateur used two R40C1 37 X 23 X 7 mm ferrite toroids and 165/46 litz wire to wound a coil, the Q are all over 1212Q between 500 – 1700 KHz, the highest point is 1471Q at 900 KHz.

For more information of this R40C1 37 X 23 X 7 mm ferrite toroid, please search "The RadioBoard Forums" on google and read all interesting articles of “R40C1” in Crystal Radios section.

If you need 175/46, 250/46, 270/46, 300/48, 420/48 or 675/48 litz wire to make coils for this ferrite toroid, please visit my eBay store  mkmak222_Litz Wire to search these litz wire.

Please e-mail any questions you may have before you order.