Tweet
Ne koristim nikakve formule. Namotam zicu, izmerim, domotam ili odmotam, izmerim.... iz prakse znam da ce indkutivnost porasti za malo kada stegnem namotaje dobro, kasnije. Koliko ce porasti induktivnost....to zavisi od precnika zavojnice...opet nema formule vec se utvrdjuje empirijski. Na primer, zavojnice D oblika za DD sondu od 27cm, skoro po pravilu posle stezanja zice dobiju na induktivnosti skoro za pola mH. Dakle namotam D oblik i doteram da induktivnost bude 5.6mH i kasnije kada pritegnem zice dobije se 6mH. Ili oko 6.1mH da bi se dobilo 6,5mH posle stezanja zica. To vazi za tu velicinu i oblik sonde. Za omega sondu verovatno vaze sasvim drugacija pravila. Jednom sam jednu namotao i radila je ok. Ne secam se niti broja namotaja niti ostalih podataka. Ima ovde na ovom topic-u nekih podataka. Pretrazi. Mislim da sam tada zapisao i objavio podatke za tu sondu.
I dont have such forumula. I am not using any formula. All i done so far was by previously established experience. Usually inductance will rise for 0.4-0.5mH when tightly constrain windings after. But this is not the rule for all possible diammeters. Only for 27cm DD coil. However, i havent noticed any significant inductance changes when Al cage was applied later. So only important changes will occur when windings are later constrained.
So...i can only give here one example; coil i done so many times, and already established accurate rules. Coil 27cm DD when making; keep inductance 0.4-0.5 mH lower when wounding so to gain proper inductance later when windings are constrained. This further means you must achieve 5.6mH for TX and 6.1mH for RX. Later when constrained and Al cage applied you will get almost exact 6mH for TX and 6.5mH for RX. Doesnt really matter if final inductances varry for some 0.1mH, dont worry. More important is to keep same ratio between RX and TX, some 0.5mH. Less or more differences will cause lot of problems later when coil is about to be balanced.
But speaking of omega coil.... i dont know exact ratio. I havent done more than one omega coil. At the time i achieved proper inductances with adjusting number of windings and conctant measurements. So i dont know the ratio. Ratio for 27cm DD coil is NOT the rule for any other diammeter and shape.
I dont have such forumula. I am not using any formula. All i done so far was by previously established experience. Usually inductance will rise for 0.4-0.5mH when tightly constrain windings after. But this is not the rule for all possible diammeters. Only for 27cm DD coil. However, i havent noticed any significant inductance changes when Al cage was applied later. So only important changes will occur when windings are later constrained.
So...i can only give here one example; coil i done so many times, and already established accurate rules. Coil 27cm DD when making; keep inductance 0.4-0.5 mH lower when wounding so to gain proper inductance later when windings are constrained. This further means you must achieve 5.6mH for TX and 6.1mH for RX. Later when constrained and Al cage applied you will get almost exact 6mH for TX and 6.5mH for RX. Doesnt really matter if final inductances varry for some 0.1mH, dont worry. More important is to keep same ratio between RX and TX, some 0.5mH. Less or more differences will cause lot of problems later when coil is about to be balanced.
But speaking of omega coil.... i dont know exact ratio. I havent done more than one omega coil. At the time i achieved proper inductances with adjusting number of windings and conctant measurements. So i dont know the ratio. Ratio for 27cm DD coil is NOT the rule for any other diammeter and shape.
Comment