Monday, June 29, 2009
....Here is the infamous VHF preamplifier that let me discover the problem in the antenna input plug, no wonder it worked better with the antenna cable in short circuit that with it open, the external cable was really working as the antenna.
Now it works nice, at least improves something on the signal level, without the amplifier I have for instance S4, with the amplifier goes to S5, not bad but not great either...could be good for marginal signals.
You probably can use the orignal design, I started testing with the coils but then remove them until I found the problem was the antenna input. Mine is working like on the schematic... less is more :)
Now the airband receiver continues to not working well, will buy another TDA1072 to check it it's broken.