I'm looking for some obsolete semiconductors. I've tried some of the
vendors in the repair FAQ. The problem is that I need between one to
ten parts. The vendors all want quotes in the thousands with anywhere
between a $100 to $400 minimum order depending on the vendor. When I
asked for a quote, most did not even bother to respond to a small
quanity order. Does anyone have a recommended source for obsolete
semiconductors that doesn't have a sky high minimum order?

For the curious, I'm currently looking for some TL607 FET Switches.

Don't suggest Digikey, Mouser, MDM, Newark, etc. The part is too old
and not carried by these.


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice http://www.LearnByDestroying.com
# http://802.11junk.com
#
# AE6KS

"Jeff Liebermann" wrote in message
...

For the curious, I'm currently looking for some TL607 FET Switches.

Why that part?

N

On Sat, 30 Jul 2005 06:40:08 GMT, "NSM" wrote:


"Jeff Liebermann" wrote in message
.. .

For the curious, I'm currently looking for some TL607 FET Switches.

Why that part?

It's for a Wavetek 3000B service monitor. Most of the IC's are in
sockets which makes troubleshooting rather easy. This particular FET
switch is used for switching the front panel meter. There are about 8
of them in the unit. Some clues as to whether it needed replacement
are the melted IC socket and the larger volume of smog that the chip
generated. To the best of knowledge, there is no substitute or
equivalent. I have temporarily thrown together a piggy back board
with a 4066 FET switch and 4069 inverter that was sufficient for
getting things running. However, I would prefer the real part.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
AE6KS 831-336-2558

"Jeff Liebermann" wrote in message
...

For the curious, I'm currently looking for some TL607 FET Switches.

However, I would prefer the real part.

That's a tough one!

N

On Sat, 30 Jul 2005 18:17:50 GMT, "NSM" wrote:


"Jeff Liebermann" wrote in message
.. .

For the curious, I'm currently looking for some TL607 FET Switches.

However, I would prefer the real part.

That's a tough one!

Not really. I've practiced parts cannibalism and circuit redesign
before in order to replace obsolete parts. I recently performed a
radical substitution for the traditional blown flyback xformer in a
Tek T922 scope. If you know how the circuit works (and have an
accurate schematic), then such redesign and substitutions are easy
enough.

However, I'm lazy and have a limited amount of time to redesign the
circuitry. I bought the Wavetek 3000b on eBay for about 60% of what
it was worth. Having worked with similar vintage service monitors
(Cushman, SSI, CT Systtems, TFT, etc), I thought it would be fairly
easy to repair. Identifying the smoking part was easy enough.
Replacing the melted socket was not much of a challenge. However, I'm
currently stuck at finding a replacement IC.

This is not the first time I've searched for old parts. What I've
found are various online "parts finder" sites, that will offer to find
obsolete semiconductors. The ritual is to fill in an online request
for a quote, and they will allegedly contact me with price and
availability. All of them list their inventory online and most show a
TL607 in stock, somewhere. One claims to have 11,000 available. If I
needed 11,000 parts, this vendor might be useful, but I only need a
few parts. In general, *AFTER* I fill in the info for a quote, the
web page announces that there's anywhere between a $100 and $400
minimum purchase. Incidentally, the $100 is a lie because this vendor
wants another $100 for "shipping and handling".

So, what I need is an online vendor, that sells small quantities of
obsolete semiconductors and IC's, that doesn't have a ridiculous
minimum. I suspect that this is a chronic and common problem in the
repair biz and was hoping that someone knew of a reliable source.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
AE6KS 831-336-2558

Datasheet for the part:

http://focus.ti.com/docs/prod/folders/print/tl607.html

JUNE 1976 - REVISED OCTOBER 1986

Perhaps someone could suggest an alternative part...



"Jeff Liebermann" wrote in message
...
On Sat, 30 Jul 2005 18:17:50 GMT, "NSM" wrote:


"Jeff Liebermann" wrote in message
. ..

For the curious, I'm currently looking for some TL607 FET Switches.

However, I would prefer the real part.

That's a tough one!

Not really. I've practiced parts cannibalism and circuit redesign
before in order to replace obsolete parts. I recently performed a
radical substitution for the traditional blown flyback xformer in a
Tek T922 scope. If you know how the circuit works (and have an
accurate schematic), then such redesign and substitutions are easy
enough.

However, I'm lazy and have a limited amount of time to redesign the
circuitry. I bought the Wavetek 3000b on eBay for about 60% of what
it was worth. Having worked with similar vintage service monitors
(Cushman, SSI, CT Systtems, TFT, etc), I thought it would be fairly
easy to repair. Identifying the smoking part was easy enough.
Replacing the melted socket was not much of a challenge. However, I'm
currently stuck at finding a replacement IC.

This is not the first time I've searched for old parts. What I've
found are various online "parts finder" sites, that will offer to find
obsolete semiconductors. The ritual is to fill in an online request
for a quote, and they will allegedly contact me with price and
availability. All of them list their inventory online and most show a
TL607 in stock, somewhere. One claims to have 11,000 available. If I
needed 11,000 parts, this vendor might be useful, but I only need a
few parts. In general, *AFTER* I fill in the info for a quote, the
web page announces that there's anywhere between a $100 and $400
minimum purchase. Incidentally, the $100 is a lie because this vendor
wants another $100 for "shipping and handling".

So, what I need is an online vendor, that sells small quantities of
obsolete semiconductors and IC's, that doesn't have a ridiculous
minimum. I suspect that this is a chronic and common problem in the
repair biz and was hoping that someone knew of a reliable source.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
AE6KS 831-336-2558

"Jeff Liebermann" wrote in message
...

So, what I need is an online vendor, that sells small quantities of
obsolete semiconductors and IC's, that doesn't have a ridiculous
minimum. I suspect that this is a chronic and common problem in the
repair biz and was hoping that someone knew of a reliable source.

I've surfed the Australian sellers like Jaycar because they often have small
quantities.

N

On Sat, 30 Jul 2005 00:38:13 -0700 Jeff Liebermann
wrote:

For the curious, I'm currently looking for some TL607 FET Switches.

I would prefer the real part.

Have you tried just Googleing on the part #? Sometimes that will show
up some in some odd inventory somewhere. There are surplus houses that
may have them as well as individuals who might be tickled pink to get
rid of a dozen.

We know they're out there; it's just a question of getting the willing
buyer and the willing seller together.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

On Sun, 31 Jul 2005 21:10:55 -0500, Jim Adney
wrote:

On Sat, 30 Jul 2005 00:38:13 -0700 Jeff Liebermann
wrote:

For the curious, I'm currently looking for some TL607 FET Switches.

I would prefer the real part.

Have you tried just Googleing on the part #?

Of course I have. That's one way I found a selection of uncooperative
and overpriced obsolete semiconductor vendors. The other is from the
repair FAQ. These vendors maintain their "inventory" online and
Google finds them easily. The common theme and problem is the $100 to
$400 minimum order.

Try searching Google for:
obsolete semiconductors "minimum order"
as in:

http://www.google.com/search?hl=en&q...mum+ order%22
and note the assorted minimum order amounts. Hmmm... There's one I
haven't tried with a $75 minimum order. Might as well try them.

Sometimes that will show
up some in some odd inventory somewhere. There are surplus houses that
may have them as well as individuals who might be tickled pink to get
rid of a dozen.

Well, that's what I've been asking. So far, I haven't found a willing
surplus house and was hoping that someone with a similar problem had
found a willing vendor or supplier. Assuming that repair shops still
exist that actually do component level repairs, I would think that
finding obsolete and ancient parts to be a common problem.

We know they're out there; it's just a question of getting the willing
buyer and the willing seller together.

Yep. That's exactly my problem. I'm a cheap and willing buyer
looking for an inexpensive and willing seller with inventory.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
AE6KS 831-336-2558

On Sun, 31 Jul 2005 19:49:42 -0700 Jeff Liebermann
wrote in Message id:
:

Well, that's what I've been asking. So far, I haven't found a willing
surplus house and was hoping that someone with a similar problem had
found a willing vendor or supplier. Assuming that repair shops still
exist that actually do component level repairs, I would think that
finding obsolete and ancient parts to be a common problem.

Have you tried these folks?
http://www.rocelec.com/

They list the device you're looking for as WIP with an 18 week lead time,
if you can wait. We buy small quantities (10) of old DAC80 and AM2504
parts for support occasionally. These folks actually purchase the masks
from the original vendors when they go EOL.

On Mon, 01 Aug 2005 10:43:28 -0400, JW wrote:

On Sun, 31 Jul 2005 19:49:42 -0700 Jeff Liebermann
wrote in Message id:
:

Well, that's what I've been asking. So far, I haven't found a willing
surplus house and was hoping that someone with a similar problem had
found a willing vendor or supplier. Assuming that repair shops still
exist that actually do component level repairs, I would think that
finding obsolete and ancient parts to be a common problem.

Have you tried these folks?
http://www.rocelec.com/

Well, that's a bit extreme. I didn't know anyone was doing such
things. I this case, 18 weeks is a bit too long and I suspect making
a single wafer to supply about 10 parts is going to be rather
expensive. I'll keep pounding on the "obsolete semiconductor" vendors
until I find one that cooperates. Thanks much for the info.

They list the device you're looking for as WIP with an 18 week lead time,
if you can wait. We buy small quantities (10) of old DAC80 and AM2504
parts for support occasionally. These folks actually purchase the masks
from the original vendors when they go EOL.


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice http://www.LearnByDestroying.com
# http://802.11junk.com
#
# AE6KS

Jeff Liebermann wrote:

Well, that's a bit extreme. I didn't know anyone was doing such
things. I this case, 18 weeks is a bit too long and I suspect making
a single wafer to supply about 10 parts is going to be rather
expensive. I'll keep pounding on the "obsolete semiconductor" vendors
until I find one that cooperates. Thanks much for the info.


They sometimes have the last wafer or two that was made by the OEM
before the finished part was discontinued. On the other hand, they don't
deal in small quantities. It would be nice if they would forward your
request to the last company to buy the parts to see if they would sell a
few.

--
Link to my "Computers for disabled Veterans" project website deleted
after threats were telephoned to my church.

Michael A. Terrell
Central Florida

"Michael A. Terrell" wrote in message
...

Link to my "Computers for disabled Veterans" project website deleted
after threats were telephoned to my church.

No shortage of deranged idiots in the world!

N

On Mon, 01 Aug 2005 23:04:01 GMT, "Michael A. Terrell"
wrote:

They sometimes have the last wafer or two that was made by the OEM
before the finished part was discontinued. On the other hand, they don't
deal in small quantities. It would be nice if they would forward your
request to the last company to buy the parts to see if they would sell a
few.

Well, the TL607 was discontinues in the late 1980's so I don't think
anyone is going to have 15 year old inventory laying around. Probably
a good idea for more current obsolet components.

For entertainment value, the best quote so far is $5/chip with a 35
piece minimum, plus shipping. Grand total is about $170. Kinda
expensive to fix a $300 piece of test equipment. However, I may have
to take it if I can't find another source.

Grumble, grumble...


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice http://www.LearnByDestroying.com
# http://802.11junk.com
#
# AE6KS

Jeff Liebermann wrote:

Well, the TL607 was discontinues in the late 1980's so I don't think
anyone is going to have 15 year old inventory laying around. Probably
a good idea for more current obsolet components.

For entertainment value, the best quote so far is $5/chip with a 35
piece minimum, plus shipping. Grand total is about $170. Kinda
expensive to fix a $300 piece of test equipment. However, I may have
to take it if I can't find another source.

Grumble, grumble...


If you do, make sure to list the extras for sale on a website
somewhere, because there have to be other people who will need one or
more for a repair. I have someone order a couple NEC MC-5800 Hybrid
RF/IF amplifier modules from my website. I am probably the only one
listing this part outside of the big brokers. If I had the money I
would like to deal in the spot market and buy some of these hard to find
chips to sell in smaller quantities.

I am now disabled and can't do a lot of repairs so i listed a small
part of my parts collection on a website to help others find a few parts
here and there. http://home.earthlink.net/~mike.terrell/ was created to
show how easy it is to build a cut & paste website so others can find
what you no longer need, or have excess stock.

--
Link to my "Computers for disabled Veterans" project website deleted
after threats were telephoned to my church.

Michael A. Terrell
Central Florida