15 May
2012
15 May
'12
11:48 a.m.
Indeed, I bought a Hameg HM605, it was working OK,
although not fully
calibrated. But it has now developed a fault, with the probe not connected
to anything, move the y-POS off the zero line and you get a 100Hz square
wave. Might need another scope to fix this one....
Sounds ike you've got ripple on one of the supply lines for the Y amplifier.
Do you have the schematics (Hameg used to be good about puttign those i
nthe manual). If so, find out what supplies are used for the Y amplidier
nad check/replace the large electrolytics associated with them (this is s
linear supply with a nice big transformer, so it's not too ahrd to fix).
[AT PSUs}
Yes I have a few of those lying around, but I have been advised to get a
variable one with current limiting. I have already had two explosions after
testing suggested the board was working again and could be put back into the
PSU, so testing it under controlled conditions would be desirable.
An adjustable bench supply is also a very useful thing to have. One
important feature that a lot of neew ones can't to is the ability to go
right down to 0V on the output. The modern SMPUS-based ones start at 1V
or so. Which is a right pain if you want to ramp the votlage up from nothing.
Fiarly obviosuly the thing I use the most often is a multimeter. I think
the bench PSU comes next (if you can't power sonmething, you can't test
it :-)), then eitehr a 'scope or a logic analyser depending on what it is
I am working on.
-tony