Topics

Tek 3A1 Module


David Kuhn
 

Are these modules difficult to come up with? There is one on EBAY for
$400, stating "UNTESTED AS-IS".

I just ask because I picked up a 564 Scope, but it has 3A72 module in it
(BW only about half a MHz). The Manual shows that with a 3A1, you can get
10MHz bandwidth out of the scope.

There is a 3A1 along with two sweep modules listed as "part only with all
the tubes missing" for $40 on EBAY.

This is nothing urgent The 564 has great sharp traces (with the sweep
compressed there is power supply noise - it will need re-capped). Over the
winter, I plan to build up a hobby bench, away from my business work
benches. I will use it to work on old electronic restoration and what not.

If I do find one on ebay, what should I expect to pay for one?

Thanks kindly,

Dave


David Holland
 

That <cough> might be a little much.....

I don't think I'd pay more than about 30-50$ (US) for a "common" 560 series
plugin, in good physical condition, with all its tubes.... There's a few
rarer one's I'd pay good money (significantly more) for though, since I've
yet to get any eBay hits for them. :-)

Usually the one's sans tubes are missing the 6DJ8's and/or nuvistors, since
they're desired by the audiophool crowd. If you don't have a supply of
tubes handy, purchasing replacements isn't terrible, since you don't need
the gold plated, cryogenically frozen, oxygen free 6DJ8's, but it's
something to keep in mind when looking at a denuded plugin. (Plain 6DJ8's
are just fine.)

You might keep an eye out for a 3A6, it's 10Mhz w/ a 260ns delay line.
10Mhz is the max for the 561A & B, 564's. IIRC, there is a 561S that is
spec'd for 25Mhz, but it requires the two S series plugins as well. (See
TekWiki for many more details)

David

On Mon, Nov 23, 2020 at 5:34 PM David Kuhn <Daveyk021@gmail.com> wrote:

Are these modules difficult to come up with? There is one on EBAY for
$400, stating "UNTESTED AS-IS".

I just ask because I picked up a 564 Scope, but it has 3A72 module in it
(BW only about half a MHz). The Manual shows that with a 3A1, you can get
10MHz bandwidth out of the scope.

There is a 3A1 along with two sweep modules listed as "part only with all
the tubes missing" for $40 on EBAY.

This is nothing urgent The 564 has great sharp traces (with the sweep
compressed there is power supply noise - it will need re-capped). Over the
winter, I plan to build up a hobby bench, away from my business work
benches. I will use it to work on old electronic restoration and what not.

If I do find one on ebay, what should I expect to pay for one?

Thanks kindly,

Dave






David Holland
 

I should add...560 series plugins aren't terribly hard to find on eBay,
however, they may come attached to a mainframe, however, which definitely
impacts shipping.

Prices do seem to have gone up the last few years though..

On Mon, Nov 23, 2020 at 8:29 PM David Holland via groups.io
<david.w.holland=gmail.com@groups.io> wrote:

That <cough> might be a little much.....

I don't think I'd pay more than about 30-50$ (US) for a "common" 560 series
plugin, in good physical condition, with all its tubes.... There's a few
rarer one's I'd pay good money (significantly more) for though, since I've
yet to get any eBay hits for them. :-)

Usually the one's sans tubes are missing the 6DJ8's and/or nuvistors, since
they're desired by the audiophool crowd. If you don't have a supply of
tubes handy, purchasing replacements isn't terrible, since you don't need
the gold plated, cryogenically frozen, oxygen free 6DJ8's, but it's
something to keep in mind when looking at a denuded plugin. (Plain 6DJ8's
are just fine.)

You might keep an eye out for a 3A6, it's 10Mhz w/ a 260ns delay line.
10Mhz is the max for the 561A & B, 564's. IIRC, there is a 561S that is
spec'd for 25Mhz, but it requires the two S series plugins as well. (See
TekWiki for many more details)

David

On Mon, Nov 23, 2020 at 5:34 PM David Kuhn <Daveyk021@gmail.com> wrote:

Are these modules difficult to come up with? There is one on EBAY for
$400, stating "UNTESTED AS-IS".

I just ask because I picked up a 564 Scope, but it has 3A72 module in it
(BW only about half a MHz). The Manual shows that with a 3A1, you can
get
10MHz bandwidth out of the scope.

There is a 3A1 along with two sweep modules listed as "part only with all
the tubes missing" for $40 on EBAY.

This is nothing urgent The 564 has great sharp traces (with the sweep
compressed there is power supply noise - it will need re-capped). Over
the
winter, I plan to build up a hobby bench, away from my business work
benches. I will use it to work on old electronic restoration and what
not.

If I do find one on ebay, what should I expect to pay for one?

Thanks kindly,

Dave










David Kuhn
 

Thank you. Besides the 6DJ8 tubes, what other ones would be missing from
the 3A1 module?

There also nuvistors in it? I used to have a nuvustor or two but don’t
remember the number. The ones I had were used for the first stage RF amp in
an industrial UT instrument.

Dave

On Mon, Nov 23, 2020 at 8:29 PM David Holland <david.w.holland@gmail.com>
wrote:

That <cough> might be a little much.....

I don't think I'd pay more than about 30-50$ (US) for a "common" 560 series
plugin, in good physical condition, with all its tubes.... There's a few
rarer one's I'd pay good money (significantly more) for though, since I've
yet to get any eBay hits for them. :-)

Usually the one's sans tubes are missing the 6DJ8's and/or nuvistors, since
they're desired by the audiophool crowd. If you don't have a supply of
tubes handy, purchasing replacements isn't terrible, since you don't need
the gold plated, cryogenically frozen, oxygen free 6DJ8's, but it's
something to keep in mind when looking at a denuded plugin. (Plain 6DJ8's
are just fine.)

You might keep an eye out for a 3A6, it's 10Mhz w/ a 260ns delay line.
10Mhz is the max for the 561A & B, 564's. IIRC, there is a 561S that is
spec'd for 25Mhz, but it requires the two S series plugins as well. (See
TekWiki for many more details)

David

On Mon, Nov 23, 2020 at 5:34 PM David Kuhn <Daveyk021@gmail.com> wrote:

Are these modules difficult to come up with? There is one on EBAY for
$400, stating "UNTESTED AS-IS".

I just ask because I picked up a 564 Scope, but it has 3A72 module in it
(BW only about half a MHz). The Manual shows that with a 3A1, you can
get
10MHz bandwidth out of the scope.

There is a 3A1 along with two sweep modules listed as "part only with all
the tubes missing" for $40 on EBAY.

This is nothing urgent The 564 has great sharp traces (with the sweep
compressed there is power supply noise - it will need re-capped). Over
the
winter, I plan to build up a hobby bench, away from my business work
benches. I will use it to work on old electronic restoration and what
not.

If I do find one on ebay, what should I expect to pay for one?

Thanks kindly,

Dave










Brenda
 

Hello Dave, The 3A1 plugins that I have come across ends up not only the 6DJ8 tubes missing, there are 2 8233 tubes that end up missing as well. There are 4 7586 nuvistor tubes in the front end, but seems like the tube pickers pass over these from my experience. I am in the market for a few 3A1 and 3A6 plugins myself...at a reasonable price, $400 is just way too much!!


David Holland
 

Yeah, as Brenda said....

The manuals detail what vacuum tubes are in the plugins. I'd pay close
attention to any photos as I've gotten burnt once or twice by not paying
attention to them. I would presume if there's no photos, and no statement
one way or the other, that the tubes are missing.

If you start getting into the advanced (sampling) plugins, I would pay
closer attention to the photos for the presence of the transistors, as most
of them are socketed, long obsolete, and made from 99.95% pure unobtanium.

A few plugins (ex: 3B3) use tunnel diodes, but as far as I've seen, they're
generally soldered to the board. Tunnel diodes are also mostly made of
unobtanium, and may be dead, but at least they'll likely still be there...
:-)

Again, the various plugin manuals all have a relatively complete parts list
in the back, if you wonder what should be in a given plugin.

David


On Tue, Nov 24, 2020 at 12:05 PM Brenda via groups.io <brendda75=
yahoo.com@groups.io> wrote:

Hello Dave, The 3A1 plugins that I have come across ends up not only the
6DJ8 tubes missing, there are 2 8233 tubes that end up missing as well.
There are 4 7586 nuvistor tubes in the front end, but seems like the tube
pickers pass over these from my experience. I am in the market for a few
3A1 and 3A6 plugins myself...at a reasonable price, $400 is just way too
much!!






-
 

My rule of thumb when looking at electronic equipment on E-bay or
anywhere else is to look *closely* for signs that anyone has been into it.
If it isn't *sealed* and it's not guaranteed to work then expect the
worst. I wouldn't pay more than a *minimal* price for anything that has
been opened and that isn't guaranteed to operate properly. I've seen far
too much equipment for sale by big time used equipment dealers such as
Tucker Electronics being sold in "as-is" condition that I'm sure have
already been stripped of anything useful.

On Wed, Nov 25, 2020 at 10:08 AM David Holland <david.w.holland@gmail.com>
wrote:

Yeah, as Brenda said....

The manuals detail what vacuum tubes are in the plugins. I'd pay close
attention to any photos as I've gotten burnt once or twice by not paying
attention to them. I would presume if there's no photos, and no statement
one way or the other, that the tubes are missing.

If you start getting into the advanced (sampling) plugins, I would pay
closer attention to the photos for the presence of the transistors, as most
of them are socketed, long obsolete, and made from 99.95% pure unobtanium.

A few plugins (ex: 3B3) use tunnel diodes, but as far as I've seen, they're
generally soldered to the board. Tunnel diodes are also mostly made of
unobtanium, and may be dead, but at least they'll likely still be there...
:-)

Again, the various plugin manuals all have a relatively complete parts list
in the back, if you wonder what should be in a given plugin.

David


On Tue, Nov 24, 2020 at 12:05 PM Brenda via groups.io <brendda75=
yahoo.com@groups.io> wrote:

Hello Dave, The 3A1 plugins that I have come across ends up not only the
6DJ8 tubes missing, there are 2 8233 tubes that end up missing as well.
There are 4 7586 nuvistor tubes in the front end, but seems like the tube
pickers pass over these from my experience. I am in the market for a few
3A1 and 3A6 plugins myself...at a reasonable price, $400 is just way too
much!!










David Kuhn
 

If not for FleaBay, then where else can one obtain these old scope modules?

On Wed, Nov 25, 2020 at 1:19 PM - <rrrr6789@gmail.com> wrote:

My rule of thumb when looking at electronic equipment on E-bay or
anywhere else is to look *closely* for signs that anyone has been into it.
If it isn't *sealed* and it's not guaranteed to work then expect the
worst. I wouldn't pay more than a *minimal* price for anything that has
been opened and that isn't guaranteed to operate properly. I've seen far
too much equipment for sale by big time used equipment dealers such as
Tucker Electronics being sold in "as-is" condition that I'm sure have
already been stripped of anything useful.

On Wed, Nov 25, 2020 at 10:08 AM David Holland <david.w.holland@gmail.com>
wrote:

Yeah, as Brenda said....

The manuals detail what vacuum tubes are in the plugins. I'd pay close
attention to any photos as I've gotten burnt once or twice by not paying
attention to them. I would presume if there's no photos, and no
statement
one way or the other, that the tubes are missing.

If you start getting into the advanced (sampling) plugins, I would pay
closer attention to the photos for the presence of the transistors, as
most
of them are socketed, long obsolete, and made from 99.95% pure
unobtanium.

A few plugins (ex: 3B3) use tunnel diodes, but as far as I've seen,
they're
generally soldered to the board. Tunnel diodes are also mostly made of
unobtanium, and may be dead, but at least they'll likely still be
there...
:-)

Again, the various plugin manuals all have a relatively complete parts
list
in the back, if you wonder what should be in a given plugin.

David


On Tue, Nov 24, 2020 at 12:05 PM Brenda via groups.io <brendda75=
yahoo.com@groups.io> wrote:

Hello Dave, The 3A1 plugins that I have come across ends up not only
the
6DJ8 tubes missing, there are 2 8233 tubes that end up missing as well.
There are 4 7586 nuvistor tubes in the front end, but seems like the
tube
pickers pass over these from my experience. I am in the market for a
few
3A1 and 3A6 plugins myself...at a reasonable price, $400 is just way
too
much!!














David Holland
 

Today, with that which shall not be named still around?

Ummm, FairRadio (in Lima, OH) has (had?) some of the more common ones in
back... - (No affiliation, just a customer).

IIRC, they were in what I would at least consider fair condition. They'll
probably be kind of expensive, but you should be able to stipulate that
they have all their tubes. You'll probably want to send them an email,
their website is not at all complete.

After that, I dunno, you're back to ePay...<shrug> If anyone has any
suggestions, I'd love to hear them as well. I have a few plugins I'd like
to find. (A 3B5 particularly.)

David

On Wed, Nov 25, 2020 at 2:38 PM David Kuhn <Daveyk021@gmail.com> wrote:

If not for FleaBay, then where else can one obtain these old scope modules?

On Wed, Nov 25, 2020 at 1:19 PM - <rrrr6789@gmail.com> wrote:

My rule of thumb when looking at electronic equipment on E-bay or
anywhere else is to look *closely* for signs that anyone has been into
it.
If it isn't *sealed* and it's not guaranteed to work then expect the
worst. I wouldn't pay more than a *minimal* price for anything that has
been opened and that isn't guaranteed to operate properly. I've seen far
too much equipment for sale by big time used equipment dealers such as
Tucker Electronics being sold in "as-is" condition that I'm sure have
already been stripped of anything useful.

On Wed, Nov 25, 2020 at 10:08 AM David Holland <
david.w.holland@gmail.com>
wrote:

Yeah, as Brenda said....

The manuals detail what vacuum tubes are in the plugins. I'd pay
close
attention to any photos as I've gotten burnt once or twice by not
paying
attention to them. I would presume if there's no photos, and no
statement
one way or the other, that the tubes are missing.

If you start getting into the advanced (sampling) plugins, I would pay
closer attention to the photos for the presence of the transistors, as
most
of them are socketed, long obsolete, and made from 99.95% pure
unobtanium.

A few plugins (ex: 3B3) use tunnel diodes, but as far as I've seen,
they're
generally soldered to the board. Tunnel diodes are also mostly made
of
unobtanium, and may be dead, but at least they'll likely still be
there...
:-)

Again, the various plugin manuals all have a relatively complete parts
list
in the back, if you wonder what should be in a given plugin.

David


On Tue, Nov 24, 2020 at 12:05 PM Brenda via groups.io <brendda75=
yahoo.com@groups.io> wrote:

Hello Dave, The 3A1 plugins that I have come across ends up not only
the
6DJ8 tubes missing, there are 2 8233 tubes that end up missing as
well.
There are 4 7586 nuvistor tubes in the front end, but seems like the
tube
pickers pass over these from my experience. I am in the market for a
few
3A1 and 3A6 plugins myself...at a reasonable price, $400 is just way
too
much!!


















Ken Bratz
 

Try: VintageTek Museum / https://vintagetek.org /
Call, they aren’t there every day. Their web page only shows manuals, but they can scrounge up other items. They sell items to cover operating costs. They are on the Tek campus.


-
 

"If not for FleaBay, then where else can one obtain these old scope
modules?"

They show up pretty regularly at the surplus stores around here. I just
bought two TM500 (DM502 and FG502) plugins for $5 at a store near here and
they still have three plugins for the Tek 7000 scopes there (don't recall
what they were now.) Also on Craigslist. Also lots of the guys that
collect vintage computers or other types of electronics come across them
regularly and most have some laying around that they got with other
equipment. Also hamfests. You just have to get out and beat the bushes,
or pay the inflated E-Greed prices.

I watch Fleabay pretty closely for anything of interest that's nearby
and that I can go and pick up in person and save the shipping costs and
damage.

Put a want ad on Craigslist. It's free.

On Wed, Nov 25, 2020 at 2:38 PM David Kuhn <Daveyk021@gmail.com> wrote:

If not for FleaBay, then where else can one obtain these old scope modules?

On Wed, Nov 25, 2020 at 1:19 PM - <rrrr6789@gmail.com> wrote:

My rule of thumb when looking at electronic equipment on E-bay or
anywhere else is to look *closely* for signs that anyone has been into
it.
If it isn't *sealed* and it's not guaranteed to work then expect the
worst. I wouldn't pay more than a *minimal* price for anything that has
been opened and that isn't guaranteed to operate properly. I've seen far
too much equipment for sale by big time used equipment dealers such as
Tucker Electronics being sold in "as-is" condition that I'm sure have
already been stripped of anything useful.

On Wed, Nov 25, 2020 at 10:08 AM David Holland <
david.w.holland@gmail.com>
wrote:

Yeah, as Brenda said....

The manuals detail what vacuum tubes are in the plugins. I'd pay
close
attention to any photos as I've gotten burnt once or twice by not
paying
attention to them. I would presume if there's no photos, and no
statement
one way or the other, that the tubes are missing.

If you start getting into the advanced (sampling) plugins, I would pay
closer attention to the photos for the presence of the transistors, as
most
of them are socketed, long obsolete, and made from 99.95% pure
unobtanium.

A few plugins (ex: 3B3) use tunnel diodes, but as far as I've seen,
they're
generally soldered to the board. Tunnel diodes are also mostly made
of
unobtanium, and may be dead, but at least they'll likely still be
there...
:-)

Again, the various plugin manuals all have a relatively complete parts
list
in the back, if you wonder what should be in a given plugin.

David


On Tue, Nov 24, 2020 at 12:05 PM Brenda via groups.io <brendda75=
yahoo.com@groups.io> wrote:

Hello Dave, The 3A1 plugins that I have come across ends up not only
the
6DJ8 tubes missing, there are 2 8233 tubes that end up missing as
well.
There are 4 7586 nuvistor tubes in the front end, but seems like the
tube
pickers pass over these from my experience. I am in the market for a
few
3A1 and 3A6 plugins myself...at a reasonable price, $400 is just way
too
much!!


















David Kuhn
 

" Ummm, FairRadio (in Lima, OH) has (had?) some of the more common ones in
back... - (No affiliation, just a customer)."

Thank you David. I have emailed them, as you suggest. Their web
site shows that they do have one, or more. I emailed to ask them if the
modules were complete (I did say that I can not ask them if they work, just
that they are not stripped of tubes and other parts). I'll await their
response.

They are only 6.5 hours away (lol). Once all this pandemic BS is over and
we have our President Biden manaded inoculations, I would like to take a
weekend trip out there and visit them and the big flea markets between
Dayton and Cincinnati. Sounds like a nice trip for this spring or next
summer (I pray this virus is over by then). In the meantime, I can have
them ship stuff to me.

Dave

On Wed, Nov 25, 2020 at 3:51 PM David Holland <david.w.holland@gmail.com>
wrote:

Today, with that which shall not be named still around?

Ummm, FairRadio (in Lima, OH) has (had?) some of the more common ones in
back... - (No affiliation, just a customer).

IIRC, they were in what I would at least consider fair condition. They'll
probably be kind of expensive, but you should be able to stipulate that
they have all their tubes. You'll probably want to send them an email,
their website is not at all complete.

After that, I dunno, you're back to ePay...<shrug> If anyone has any
suggestions, I'd love to hear them as well. I have a few plugins I'd like
to find. (A 3B5 particularly.)

David


On Wed, Nov 25, 2020 at 2:38 PM David Kuhn <Daveyk021@gmail.com> wrote:

If not for FleaBay, then where else can one obtain these old scope
modules?

On Wed, Nov 25, 2020 at 1:19 PM - <rrrr6789@gmail.com> wrote:

My rule of thumb when looking at electronic equipment on E-bay or
anywhere else is to look *closely* for signs that anyone has been into
it.
If it isn't *sealed* and it's not guaranteed to work then expect the
worst. I wouldn't pay more than a *minimal* price for anything that
has
been opened and that isn't guaranteed to operate properly. I've seen
far
too much equipment for sale by big time used equipment dealers such as
Tucker Electronics being sold in "as-is" condition that I'm sure have
already been stripped of anything useful.

On Wed, Nov 25, 2020 at 10:08 AM David Holland <
david.w.holland@gmail.com>
wrote:

Yeah, as Brenda said....

The manuals detail what vacuum tubes are in the plugins. I'd pay
close
attention to any photos as I've gotten burnt once or twice by not
paying
attention to them. I would presume if there's no photos, and no
statement
one way or the other, that the tubes are missing.

If you start getting into the advanced (sampling) plugins, I would
pay
closer attention to the photos for the presence of the transistors,
as
most
of them are socketed, long obsolete, and made from 99.95% pure
unobtanium.

A few plugins (ex: 3B3) use tunnel diodes, but as far as I've seen,
they're
generally soldered to the board. Tunnel diodes are also mostly made
of
unobtanium, and may be dead, but at least they'll likely still be
there...
:-)

Again, the various plugin manuals all have a relatively complete
parts
list
in the back, if you wonder what should be in a given plugin.

David


On Tue, Nov 24, 2020 at 12:05 PM Brenda via groups.io <brendda75=
yahoo.com@groups.io> wrote:

Hello Dave, The 3A1 plugins that I have come across ends up not
only
the
6DJ8 tubes missing, there are 2 8233 tubes that end up missing as
well.
There are 4 7586 nuvistor tubes in the front end, but seems like
the
tube
pickers pass over these from my experience. I am in the market for
a
few
3A1 and 3A6 plugins myself...at a reasonable price, $400 is just
way
too
much!!