This is on a Harmon kardon Citation 11 Preamp. Replacing the Electrolytes I also tested the Jfeds with a Transistor tester. It is testing as 2 resistors consistently. The board still had output but engaging the EQ was noisy.\
It is Q506. It, Q508 and Q510 all are the same part number and test as P-Channel with symbol gate pointer close to the source lead.
As much as I have read tells me the company which made these was bought up years ago. The numbers are P1053 215 above Mfgr symbol 7233. Unable to cross reference.
It is Q506. It, Q508 and Q510 all are the same part number and test as P-Channel with symbol gate pointer close to the source lead.
As much as I have read tells me the company which made these was bought up years ago. The numbers are P1053 215 above Mfgr symbol 7233. Unable to cross reference.
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Those JFETs are part of the mute circuit. You should read a near short S to D until the +14 volts kicks in and turns them off. If the preamp won't pass a signal when first turned and then passes a signal after a few seconds I would say they are working as advertised.
Craig
Craig
Thanks for a reply.
What I was hoping for was a recommendation to replace it with. A JFET that would work within the required specs of the circuit. Your description is very help full though. This JFET is somehow buffering the contact changes made by the EQ switch. Was a silent switch and is not shockingly loud. This is the only bad component. I have two boards to compare. I will replace all three if I knew the specs.
What I was hoping for was a recommendation to replace it with. A JFET that would work within the required specs of the circuit. Your description is very help full though. This JFET is somehow buffering the contact changes made by the EQ switch. Was a silent switch and is not shockingly loud. This is the only bad component. I have two boards to compare. I will replace all three if I knew the specs.
For instance I have found these and others but not certain they will work at whatever voltages applied.
https://www.mouser.com/datasheet/2/676/jfet-2n5114-2n5115-2n5116-interfet.r00-1649100.pdf
is the 30v a minimum? Probably not. A maximum? Most likely. What is the minimum needed for operation and is the resistance sufficient before operation.
https://www.mouser.com/datasheet/2/676/jfet-2n5114-2n5115-2n5116-interfet.r00-1649100.pdf
is the 30v a minimum? Probably not. A maximum? Most likely. What is the minimum needed for operation and is the resistance sufficient before operation.
The specs are actually not critical. Use J176 or J175, under $1 at Mouser. You want a through-hole part. You want to get the data-sheet for the specific type you buy so you can identify the Gate leg (the other two go either way).