Description: Normal 0 false false false EN-US ZH-CN X-NONE You also can order the KPB-02 Crystal Radio Impedance Matching Box Installation Kit in this link: http://www.ebay.com/itm/-/152127000011?ssPageName=STRK:MESE:IT Many crystal radio fans know the Bogen T725 audio matching transformer. The builders of quality crystal radios have found them useful as a matching auto transformer between the diode output and headphones. But the maximal impedance of T725 only can reach 40KΩ. You may need higher impedance auto transformer if you want to build a better quality crystal radio. Some crystal radio fans in China are design, test and produce a new autotransformer for this target. This transformer has 18 terminals , can be match from 200KΩ to 4Ω by 17 steps. They use high permeability ferrite magnetic core and easy to get plentiful inductance with this small volume of core. The crystal radios output only have small electric current (from microampere to few milliampere), so we don’t have to worry about magnetic saturation in magnetic core. The specs of this transformer are: Dimension: L 40 X W 35 X H 27 mmPins length: 6 mmWeight: 104 gram Electrical parameter:Pin No. -- Impedance -- DC resistance 14 -- 200 KΩ -- 3.55 KΩ 13 -- 100 KΩ -- 2.04 KΩ 12 -- 40 KΩ -- 810 Ω 11 -- 20 KΩ -- 479 Ω 10 -- 10 KΩ -- 253 Ω 9 -- 5.0 KΩ -- 170 Ω 8 -- 2.5 KΩ -- 113 Ω 7 -- 1.5 KΩ -- 80 Ω 6 -- 800 Ω -- 52 Ω 5 -- 500 Ω -- 37 Ω 4 -- 300 Ω -- 24 Ω 3 -- 150 Ω -- 12 Ω 2 -- 64 Ω -- 6.7 Ω White wire -- 32 Ω -- 4.1 Ω Blue wire -- 16 Ω -- 2.2 Ω Yellow wire -- 8 Ω -- 1.4 Ω Red wire -- 4 Ω -- 1 .0 Ω 1 -- 0 Ω -- 0 Ω1 -- 0 Ω -- 0 Ω# E8 K: ` We compare the Bogen T725 and this ferrite magnetic core transformer in an actual measure, with 0.3V 1000Hz sine wave signal input at 40KΩ tap and a 300Ω resistor at 300Ω tap, the result shows the conversion efficiency are 83.5% and 94%. This small ferrite magnetic core transformer is 10.5% better than Bogen T725. Please e-mail any questions you may have before you order.
Price: 22 USD
Location: Union City, California
End Time: 2024-02-15T00:12:32.000Z
Shipping Cost: 4 USD
Product Images
Item Specifics
Restocking Fee: No
Return shipping will be paid by: Buyer
All returns accepted: Returns Accepted
Item must be returned within: 30 Days
Refund will be given as: Money back or replacement (buyer's choice)
Country/Region of Manufacture: China
Compatible Brand: Universal
Type: Crystal Radio
MPN: Does Not Apply
Brand: Unbranded/Generic
