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Bendix germanium transistor replacement help

Dan D.

Dan D.

Active Member
Currently working on an ElectroVoice receiver that's popping and pulsing 20 or so volts out the right channel speaker output. First assumption I made was the germaniums acting up. Sound reasonable? The numbers on all 4 are 43046 over 6905L. I can find absolutely nothing on them, let alone what other numbers would make good replacements. I have a small selection here, but no idea if any of them are compatible. Can anyone help? Thanks!
 
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Is the amp Cap Coupled? If so you need to have a load on the output(ie: spkrs connected or dummy load) to complete the circuit. Your symptoms are indicative of this, but it could be a different problem, ie: coupling cap is shorted, emitter resistors, output transistors, driver transistors, caps in the amp, preamp or power supply.

Just the Right Channel? If so compare each component on Right side vs it's couterpart on the left (voltage readings). Start at the input's and check both sides of each component. Where the problem rears it's Ugly head should be the output side of your culprit.

2n251 or dtg110b should be close enough for Gov't work. I ran the 43046 # thru NTE, and it came back NTE121. Also the 2n251 AND the DTG110B came back same nte#.

the 6905L is a date code. 1969 5th week. No idea on the "L". might be a plant code? DTG110B is more plentiful, but still a hens tooth item. Cheaper than the NTE part too.

Use a DBT, 60W to 75W bulb while testing. It will help reduce further degradation of the components.
 
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Thanks, Larry. I'll admit that my knowledge doesn't go much past the basics. A few things here and there made sense, but unless it's an obvious problem (something visually let the smoke out, etc.) I'm kind of shooting blind. Appreciate the cross-references, I'll check my stash for anything to temp in and see if it works. It doesn't help that this thing is a monster to work on. No connectors or plugs internally, lots of wires soldered in from one board to the next, and there are several of those...packed in an extremely tight case. It's a fight to even visually inspect the bottom/backs of the boards without disconnecting a lot of the rainbow spaghetti. The solid wood case sides sucked me in, so I refuse to give up on this thing. So far. Just too dang pretty.
 
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