Post by tzsteve on Mar 26, 2016 15:52:33 GMT
My Koso rev counter had been showing silly readings for a while.
ie,
tick over of between 5000 and 14000 RPM.
and the needle bouncing around as it wanted to.
sometimes i would be at full throttle and the needle would show zero then rocket upto 14000 before going to mid scale. so generaly as usefull as mens tits.
i then tested it on my car with similar results. so decided that as it was obviously not working i would do a more scientific test on it. so using my function generator and a small amplifier i tested it again.
this is the function generator i used (a reasonably good one)
and got the same silly results. a totaly eratic reading with the needle bouncing around as before.
so as it was no use whatsoever i decided to do a bit of an autopsy on it (even if i killed it in the process)
so i ground away the bezel that holds it all together and out comes this little lot,
with a plastic sleave holding all the components in place.
remove the guts from the plastic sleave and this is what you have. three boards, with various bits soldered to the boards.
a closer look at these boards shows what the likely cause of the poor performance is.
there are two 10 pin connectors that hold the boards together, that means a total of 20 connections these connectors are not of a very high quality and the fit on these pins could be described as loose or sloppy. it only takes one faulty connection here to make the tacho useless, i suspect this is the fault with my tacho.
also a look at the connection wires as they come through the case and where they are soldered to the first board shows poor attention to detail. there are half a dozen or so stray strands of wire that have not been solderd, although these strands are not shorting to the other wires it still shows poor workmanship.
if the two multi-pin conectors had been replaced with longer pins that had been solderd to both boards the connections would have been 100% reliable and a little time spent tidying up the wires as they are solderd to the first board would also be a good idea. it`s a shame really as the actual work on the individual boards is quite good with good quality components being used.
...............
as it is i would not recommend anything with the Koso name on it.
anyone care to recommend a decent tacho?
i know the motoplatt and schitsu ones are good but they aint cheap
ie,
tick over of between 5000 and 14000 RPM.
and the needle bouncing around as it wanted to.
sometimes i would be at full throttle and the needle would show zero then rocket upto 14000 before going to mid scale. so generaly as usefull as mens tits.
i then tested it on my car with similar results. so decided that as it was obviously not working i would do a more scientific test on it. so using my function generator and a small amplifier i tested it again.
this is the function generator i used (a reasonably good one)
and got the same silly results. a totaly eratic reading with the needle bouncing around as before.
so as it was no use whatsoever i decided to do a bit of an autopsy on it (even if i killed it in the process)
so i ground away the bezel that holds it all together and out comes this little lot,
with a plastic sleave holding all the components in place.
remove the guts from the plastic sleave and this is what you have. three boards, with various bits soldered to the boards.
a closer look at these boards shows what the likely cause of the poor performance is.
there are two 10 pin connectors that hold the boards together, that means a total of 20 connections these connectors are not of a very high quality and the fit on these pins could be described as loose or sloppy. it only takes one faulty connection here to make the tacho useless, i suspect this is the fault with my tacho.
also a look at the connection wires as they come through the case and where they are soldered to the first board shows poor attention to detail. there are half a dozen or so stray strands of wire that have not been solderd, although these strands are not shorting to the other wires it still shows poor workmanship.
if the two multi-pin conectors had been replaced with longer pins that had been solderd to both boards the connections would have been 100% reliable and a little time spent tidying up the wires as they are solderd to the first board would also be a good idea. it`s a shame really as the actual work on the individual boards is quite good with good quality components being used.
...............
as it is i would not recommend anything with the Koso name on it.
anyone care to recommend a decent tacho?
i know the motoplatt and schitsu ones are good but they aint cheap
