22-10-2011, 12:15 AM
Never seen one in the flesh.. my test for caps was and is to rip them out and replace them.. Only bridge I have ever ownde was a home made one from a 1924 design using a "r-type" (swapped by me for 1/2 ecc83) with an oscillator which ran at 1k (or thereabouts).. also from the same book I built a pretty much untuned rf amplifier using a triode wired ef80..
So how to sort out a bridge which is miles off? .. how about bashing up another on a board using known good bits and bobs and then using that to test the components you have in the faulty one?
Of course don't forget.. it's a Hunts and doubtless uses their caps (aka - random resistances with a bit of capacitance thrown in or infinite spark gaps with no capacitance whatsoever and a bit of leakage depending on the weather/proximity of warm coffee.. I'm dreading recapping my Laney.. it's full of the buggers).. so those all need replacing straight off
.. Real glaring suspect has to be the big 1µF cap.. but could be all of them .. the "brown stick" is guaranteed to be one of the odd value 1% resistances..
I remember a long time back somebody saying they had a "russian" analog meter which always read 20% out on all ranges.. running over it with the car squashed it but also fixed the "wrong" reading..
So how to sort out a bridge which is miles off? .. how about bashing up another on a board using known good bits and bobs and then using that to test the components you have in the faulty one?
Of course don't forget.. it's a Hunts and doubtless uses their caps (aka - random resistances with a bit of capacitance thrown in or infinite spark gaps with no capacitance whatsoever and a bit of leakage depending on the weather/proximity of warm coffee.. I'm dreading recapping my Laney.. it's full of the buggers).. so those all need replacing straight off
.. Real glaring suspect has to be the big 1µF cap.. but could be all of them .. the "brown stick" is guaranteed to be one of the odd value 1% resistances.. I remember a long time back somebody saying they had a "russian" analog meter which always read 20% out on all ranges.. running over it with the car squashed it but also fixed the "wrong" reading..
