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Tunnel and sampling diodes

 

Hi Craig:

The 1502 and 1503 Metallic Cable Testers (not the "B" and "C" versions) use a tunnel diode as a pulse generator and another for jitter reduction.

Schematic ref CR1609 is the jitter reduction Tunnel:
152-0140-01 Tunnel Diode 8 pF, 10 ma mfr 03508 p/n SMTD995

Schematic reference CR1703 is the pulse generator Tunnel:
152-0489-00 Tunnel GE 21 ma, 1.5 pF, w/gnd, mfr 80009, p/n 152-0631-00 (i.e. made to a Tek drawing).

I used to work for microwave related companies and worked mostly with Tunnel and other diode types, see:


While at Metelics () we supplied Tek with Step Recovery Diodes which were used in the sampling heads.
Also might have supplied beam lead Schottky diodes in a bridge configuration (different from a mixer ring configuration) which were driven by the SRD.

While at Aertech (long gone) we made tunnel diodes. I does not require a clean room and is a more or less mechanical process, i.e. no wafers, no masks and can be done in a garage.

Have Fun,

Brooke Clarke, N6GCE



Date: Mon, 15 Mar 2004 08:57:14 -0000

From: "Craig Sawyers" <c.sawyers@...>
Subject: Tunnel and sampling diodes
Hi all
Just because I'm curious, I'm trying to put together a list of the tunnel
and sampling diodes that Tek used in what instrument, and as far as possible
what their specifications are. I'm making reasonable progress, but I'm
missing details of what is in a number of instruments that clearly use them.
The ones that I have already done are:
1S1, 1S2, 7T11, 3T2, 3T6, 3T77, 485, 7B92A (early), 434, 435, 456, 464B,
475A, 184, 555, 547, 556, 453, 544, 454,
And the ones that I have identified that I *don't* have are:
5T1, 3T3. (but there may be more)
Also, Stan has identified a whole list of others that use a 4.7mA diode
(152-0125-00) he supplies:
1L40, 11B1, 11B2, 11B2A, 147A, 1470, 148, 21A (new style 555 Timebase), 22A,
408, 432, 453A, 466, 491, 5T3, 546, 7B70, 7B71, 7D11
but these probably include tunnel diodes in addition to 152-0125-00.
The other thing I'm trying to do is put together a list of sampling and snap
off (or step recovery) diodes that are used. I've done the following:
1S1, 1S2, 3S1, 3S76, S1, S2, S3/S3A, S4, S5, S6, 7S14
The ones that I know are missing are:
4S1, 4S2, 4S3, 3S5, 3S7 (again, there may be more).
Practically, what I hope to get out of this is (a) a cross reference of what
TD's are used in what instrument, so that a rare instrument can be
resurrected by use of a more common donor and (b) practical suggestions
about what diodes can be used if a sampling bridge or snap-off diode is
zapped.
So if anyone out there has some of the manuals that contain the data needed,
I'd really appreciate you having a poke around and sending me the data.
Once complete, I'll either post it to our yahoo site, or my own (or both).
Cheers
Craig

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