{"product_id":"variable-capacitor-long-shaft-65-145pf-with-mounting-screws","title":"Variable Capacitor Long Shaft 65 145pF With Mounting Screws AM VC SS","description":"\u003cp\u003eThis variable capacitor is also available with a suitable knob on another listing.\u003cbr\u003e\u003cbr\u003eThis is one item of new, dual gang miniature tuning capacitor with a solid polyethylene dielectric as shown in the pictures. The short brass shaft has been extended to 18mm with a 6mm polyethylene extension which is firmly attached with a screw. The extension allows the use of standard radio knobs designed for 6mm diameter round shafts. Two M2.5 screws are included for panel mounting along with two loose nuts which allow for spacing behind thin panels. The mounting screws must not go into the body too far or the FM capacitor sections will be damaged.\u003cbr\u003e\u003cbr\u003eThe middle connection is the common ground terminal for the two sections. The terminal next to the C3 mark is the 65pf section. The terminal next to the C4 mark is the 145pF section. You can connect the two outer connections together to make a variable capacitor of 210pF in total. The minimum capacitance of C3 is approximately 4pF. The minimum capacitance of C4 is approximately 5pF. There are two trimmers on the back. When the C3 trimmer is fully meshed this adds about 12pF capacitance. When the C4 trimmer is fully meshed this adds about 14pF. The trimmers are used to make up stray capacitance to set up the tracking in superhet radio designs. The shaft rotation is 180 degrees.\u003cbr\u003e\u003cbr\u003eYou can use these in crystal sets, TRF, regenerative radios and receiving loops where the trimmers are best set for minimum capacitance with the plates fully un-meshed. These are not suitable for transmitting loops. The long connection terminals allow the easy use of 3A mains terminal block connectors to attach wires without soldering.\u003cbr\u003e\u003cbr\u003eThe case measures 21 X 22 X 13mm. The screw threaded mounting holes accept M2.5 machine screws. 4mm long screws are suitable for mounting on fairly thin front panels. Longer screws may foul the internal parts if screwed in too far.\u003c\/p\u003e\n\u003cp\u003eA typical project might be something like this:\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/www.interestingelectronics.com\/old\/henrys_interesting_electronics\/am_radio_loop_aerial_booster\/mw_lw_am_loop_aerial_antenna.htm\" target=\"_blank\" title=\"MW \/ LW AM Radio Resonant Signal Boosting Loop Aerial\" rel=\"noopener\"\u003e\u003cspan style=\"font-family: Arial; font-size: small;\"\u003eMW \/ LW AM Radio Resonant Signal Boosting Loop Aerial\u003c\/span\u003e\u003c\/a\u003e\u003ca href=\"https:\/\/www.interestingelectronics.com\/old\/henrys_interesting_electronics\/am_radio_loop_aerial_booster\/mw_lw_am_loop_aerial_antenna.htm\" title=\"MW \/ LW AM Radio Resonant Signal Boosting Loop Aerial\"\u003e\u003cspan style=\"font-family: Arial; font-size: small;\"\u003e\u003c\/span\u003e\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003eor\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/www.interestingelectronics.com\/old\/henrys_interesting_electronics\/loud_crystal_set_radio\/loud_crystal_set_radio.htm\" target=\"_blank\" title=\"A Good Loud Crystal Radio Design With Some Justifications And Digressions\" rel=\"noopener\"\u003e\u003cspan style=\"font-family: Arial; font-size: xx-small;\"\u003e\u003cspan style=\"font-size: small;\"\u003eA Good Loud Crystal Radio Design With Some Justifications And Digressions\u003c\/span\u003e\u003c\/span\u003e\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003eor\u003cbr\u003e\u003cbr\u003e\u003ca href=\"https:\/\/www.usefulcomponents.com\/main_contents\/projects\/breadboard_trf_radio\/breadboard_trf_radio.html\" target=\"_blank\" title=\"The HJW Electronics Breadboard Six Transistor Radio Kit BBRK-1\" rel=\"noopener\"\u003eThe HJW Electronics Breadboard Six Transistor Radio Kit BBRK-1\u003c\/a\u003e\u003cbr\u003e\u003c\/p\u003e","brand":"HJW Electronics","offers":[{"title":"Default Title","offer_id":58501255725440,"sku":"AM VC SS","price":6.9,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1007\/2136\/1280\/files\/main_top_s.jpg?v=1787486177","url":"https:\/\/shop.usefulcomponents.com\/products\/variable-capacitor-long-shaft-65-145pf-with-mounting-screws","provider":"HJW Electronics","version":"1.0","type":"link"}