Re: Telequipment D34


David Tucker
 

Now that reminds me.

When I was repairing my Telequipment D61A, I needed the exact same JFET for the input amplifier - 151-1076-00.
I tried a few different JFETS, but the one that worked perfectly for that source follower was a J113. I bought 10, and most of them worked perfectly.

I know that this application is different, but if you have any J113s to hand, it might be worth a try.

Of course, a better way of doing it would be to follow Jim's advice - characterise TR104, then perhaps compare it with the datasheet for J113.

David

On Wed, Jun 10, 2020 at 02:56 PM, Jim Tibbits wrote:


what I would do ...since tr104 is the same type, i would remove tr104 and
measure its Idss...Match Idss with measured random different fet ..replace
tr104 with original, replace tr302 with matched Idss fet
that should at least get you in the ball-park
(the same type fet is used in the D32 and the D61 if you know anyone who
has parts unit)

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