¿ªÔÆÌåÓýYes, in the good old days when transformers were cheap, People who ran the 2100 amps used an auto transformer, to cut the voltage to 230V. In the generations that followed, as those amplifiers were sold and sold again, those transformers got lost.? The need for them still exists but these days, it is necessary to add a bit of resistance into the filament line, to get the voltage close to 6.3V. Fortunately, there is room in the B and Z models to accommodate some paralleled 5W wire wound resistors which drop the voltage. 73, Alek VK6APK On 19/10/2023 5:00 pm, Louis
Parascondola via groups.io wrote:
Recently looking at a FL2100B that I wanted to switch over to run on 240 instead of 120. ?Going to the manual tor switching the line voltage you¡¯ll notice that a range of input voltages are offered even 100 and 200 volts as would be needed in Japan. ?For the US the offerings ¡°listed¡± in the manual/ schematic ?are 110-117-220. ?Being an older vintage amplifier we no longer have 110-117-220 voltages! ?The nominal voltage these days are 120-240 across the country. ?Other only offering even close would be 117 and?220. ?Well the 117 wouldn¡¯t be too bad for the nominal 120v, however, ?220 is way too little to put 240 volts on to. ?We have all probably done it as it appears to be the only offering for the higher voltage. ?UPON CLOSER INSPECTION of the schematic you¡¯ll notice the transformer is a dual primary winding ?off the same taps ?both leading up to 117v each. ?Have a look. ?They do not offer?the selection to strap the primary for dual 117v winds allowing for 234v total. ?That would be way better to put 240 on 234 that on 220. ?So recently I did just that. ?I strapped it for 234v as it?would be. ?The HV is much closer to what it should be and the filament voltage would be better also. ?Does anyone have an idea why they didn¡¯t offer that? ?Only thing I can think of is they were unaware exactly how our voltage was back in the day. ?Ideas from anyone? ?Lou |
