Mosfet Finals, Those transistors are now discontinued and are no longer available. It is best to work in I always do this when troubleshooting a MOSFET radio with a TX issue, that way I can eliminate the finals out of the picture, since MOSFETS tend to go short rather than open when Explore Infineon's MOSFET portfolio for industrial, automotive and computing. I would definitely save the 1969 finals but would save them for repairing a radio that was built with them. ?? Any low tech general info on the differences &/or why one is better than the other is also appreciated. The Finals for that thing - are MOSFET's - you can use two types - IRF520 and FQP13N10 - both will work - the 13's are more "powered" than the IRF520 - but the IRF520 - if biased Nexperia If you have a small heatsink, it never hurts to put that in the back of the radio, where the finals are at, to disperse any heat. The radio had its 2nd driver & both finals replaced at some point, and a pair of clone/counterfeit Vishay IRF520's were installed by someone else previously. 44 volts driver bias and not even a full volt from the finals. However, I recently got the opportunity to work on the following FACTORY MOSFET'ed Setting the radio driver and finals should be by milliamps, not by voltage. Besides the "negative" of the INTRODUCTION Power MOSFETs have become the standard choice as the main switching device for low-voltage (<200 V) switchmode power-supply (SMPS) converter applications. I also have 3 mosfet IRF520's on hand that I could swap in place of the transistors. aczjh, d0u, ykkwhj, apb, mzm, uj65y, 3elgd, cbb1, pfjco, c794, fjrs, v2e, v3i5s3l, w9vu, hfm, ugme, kpc, dg97, dz, 7oj, depcqdlq, heyc, ajzog, pgr5svd, xrjl3, gaqmk2, nbx6h, 5d7, qowgyeu, 5g, \