Date   

Re: General Radio 874 Connector, inner conductor "bendies"

Richard Knoppow
 

FWIW a description of the 874 appeared in the General Radio Experimenter
https://www.ietlabs.com/pdf/GR_Experimenters/1948/GenRad_Experimenter_Oct_1948.pdf
The patent appears at:
https://patentimages.storage.googleapis.com/22/e8/ad/433a7c35082ad9/US2548457.pdf
This has a fairly detailed drawing.

On 8/6/2019 3:24 PM, Richard Knoppow wrote:
    I looked at a couple of 874 s just now.
--
Richard Knoppow
dickburk@ix.netcom.com
WB6KBL


Re: Tek 500 connectors or similar? A bit off topic!!!

Dave Brown
 

Further to this- I think the ones Tek used are the 26-4100 series-the ones I have that are slightly different are the 26-4200 series.
DaveB, NZ

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Dave Brown
Sent: Wednesday, August 07, 2019 16:34
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tek 500 connectors or similar? A bit off topic!!!

Yes and yes. Amphenol make 'em. Probably others as well? A local R/T manufacturer (Tait Electronics) used the red range a lot in their early VHF product so the radio could be just unplugged from the permanently mounted cradle(sound familiar!) They changed to a different connector with a coax insert when they went to 460 MHz gear as the impedance bump in the antenna lead thru the red range jobs was a bit much for up there.
There's a blue range as well- sorry can't recall what they are called just now but they are fairly common. Lots of 16 way here (ex eqpt) if you cant find any.
DaveB, NZ



-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Daniel Koller via Groups.Io
Sent: Wednesday, August 07, 2019 16:04
To: TekScopes
Subject: [TekScopes] Tek 500 connectors or similar? A bit off topic!!!

Hi all,
I have another slightly off topic but on topic question, again related to my car! You can tell I've been working on and playing with my '67 Mustang convertible lately, and btw after checking it out with my scope, and other trouble shooting, I replaced the ignition coil, and it is running absolutely perfectly now.
So anyway, years ago, while in high school (and now I mean 30 years ago) I built myself a custom "Benzi Box" for my radio. It being a convertible, I didn't want the top slashed, so someone could steel the radio. Using the original dashboard bezel, and some folded metal framework, I built a custom frame and "plug in" for the radios (you can tell how this is related now...). I have two radios I can simply swap in and out. One is a Sound Stream AM/FM cassette, the other is the original AM pushbutton radio that came with the car. A third will soon be a 1970's vintage 8-track. The plug-in around the radio connects to the frame in the car using a multi-pin connector to carry +12V, ground, stereo left/right front and back, antenna power, etc.
Now, the problem is that I used a set of connectors from a Tek 500 plug-in, as I had a few junkers at the time (and I was a bit clueless). Clearly, these are a bit more valuable to me now.
The question then, is are there any very *similar* connectors to the Amphenol blue Tek 500 plug in connectors that would serve in a similar capacity? Prefereably they would be commonly available, and be a relatively simple swap for bot the male and female versions. That would allow me to pull the two males and one female out of my radios and use them to fix the damaged connectors on a couple of Tek 500 plug-ins that need them. And I'd have something a bit more replaceable for the radios. I need at least as many pins because they are all used!

Thanks for the Ideas in advance, Dan


Re: Tek 500 connectors or similar? A bit off topic!!!

Harvey White
 

On 8/7/2019 12:04 AM, Daniel Koller via Groups.Io wrote:
Hi all,
   I have another slightly off topic but on topic question, again related to my car!  You can tell I've been working on and playing with my '67 Mustang convertible lately, and btw after checking it out with my scope, and other trouble shooting, I replaced the ignition coil, and it is running absolutely perfectly now.
  So anyway, years ago, while in high school (and now I mean 30 years ago) I built myself a custom "Benzi Box" for my radio.  It being a convertible, I didn't want the top slashed, so someone could steel the radio.   Using the original dashboard bezel, and some folded metal framework, I built a custom frame and "plug in" for the radios (you can tell how this is related now...).  I have two radios I can simply swap in and out.  One is a Sound Stream AM/FM cassette, the other is the original AM pushbutton radio that came with the car.   A third will soon be a 1970's vintage 8-track.   The plug-in around the radio connects to the frame in the car using a multi-pin connector to carry +12V, ground, stereo left/right  front and back, antenna power, etc.
   Now, the problem is that I used a set of connectors from a Tek 500 plug-in, as I had a few junkers at the time (and I was a bit clueless).   Clearly, these are a bit more valuable to me now.
   The question then, is are there any very *similar* connectors to the Amphenol blue Tek 500 plug in connectors that would serve in a similar capacity?   Prefereably they would be commonly available, and be a relatively simple swap for bot the male and female versions.   That would allow me to pull the two males and one female out of my radios and use them to fix the damaged connectors on a couple of Tek 500 plug-ins that need them.   And I'd have something a bit more replaceable for the radios.   I need at least as many pins because they are all used!
IIRC, these are amphenol blue ribbon connectors.  You might want to consider centronics style connectors, which may work.  BTW: I think that old HP equipment used them too, so depending on the age of the equipment, a check on the HP list may help.

A short check of Mouser didn't show any in the catalog.

Harvey


  Thanks for the Ideas in advance,  Dan




Re: Tek 500 connectors or similar? A bit off topic!!!

Dave Brown
 

Yes and yes. Amphenol make 'em. Probably others as well? A local R/T manufacturer (Tait Electronics) used the red range a lot in their early VHF product so the radio could be just unplugged from the permanently mounted cradle(sound familiar!) They changed to a different connector with a coax insert when they went to 460 MHz gear as the impedance bump in the antenna lead thru the red range jobs was a bit much for up there.
There's a blue range as well- sorry can't recall what they are called just now but they are fairly common. Lots of 16 way here (ex eqpt) if you cant find any.
DaveB, NZ

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Daniel Koller via Groups.Io
Sent: Wednesday, August 07, 2019 16:04
To: TekScopes
Subject: [TekScopes] Tek 500 connectors or similar? A bit off topic!!!

Hi all,
I have another slightly off topic but on topic question, again related to my car! You can tell I've been working on and playing with my '67 Mustang convertible lately, and btw after checking it out with my scope, and other trouble shooting, I replaced the ignition coil, and it is running absolutely perfectly now.
So anyway, years ago, while in high school (and now I mean 30 years ago) I built myself a custom "Benzi Box" for my radio. It being a convertible, I didn't want the top slashed, so someone could steel the radio. Using the original dashboard bezel, and some folded metal framework, I built a custom frame and "plug in" for the radios (you can tell how this is related now...). I have two radios I can simply swap in and out. One is a Sound Stream AM/FM cassette, the other is the original AM pushbutton radio that came with the car. A third will soon be a 1970's vintage 8-track. The plug-in around the radio connects to the frame in the car using a multi-pin connector to carry +12V, ground, stereo left/right front and back, antenna power, etc.
Now, the problem is that I used a set of connectors from a Tek 500 plug-in, as I had a few junkers at the time (and I was a bit clueless). Clearly, these are a bit more valuable to me now.
The question then, is are there any very *similar* connectors to the Amphenol blue Tek 500 plug in connectors that would serve in a similar capacity? Prefereably they would be commonly available, and be a relatively simple swap for bot the male and female versions. That would allow me to pull the two males and one female out of my radios and use them to fix the damaged connectors on a couple of Tek 500 plug-ins that need them. And I'd have something a bit more replaceable for the radios. I need at least as many pins because they are all used!

Thanks for the Ideas in advance, Dan


Re: Tek 500 connectors or similar? A bit off topic!!!

John Griessen
 

On 8/6/19 11:04 PM, Daniel Koller via Groups.Io wrote:
are there any very*similar* connectors to the Amphenol blue Tek 500 plug in connectors that would serve in a similar capacity?   Prefereably they would be commonly available, and be a relatively simple swap for bot the male and female versions.   That would allow me to pull the two males and one female out of my radios and use them to fix the damaged connectors on a couple of Tek 500 plug-ins that need them.
Cinch card edge connectors with 0.156 or so spacing? I have some of those in widths like 8 10 12 pairs of contacts. Can you rig a card edge to stick out of your racks/boxes?


Tek 500 connectors or similar? A bit off topic!!!

Daniel Koller
 

Hi all,
   I have another slightly off topic but on topic question, again related to my car!  You can tell I've been working on and playing with my '67 Mustang convertible lately, and btw after checking it out with my scope, and other trouble shooting, I replaced the ignition coil, and it is running absolutely perfectly now.
  So anyway, years ago, while in high school (and now I mean 30 years ago) I built myself a custom "Benzi Box" for my radio.  It being a convertible, I didn't want the top slashed, so someone could steel the radio.   Using the original dashboard bezel, and some folded metal framework, I built a custom frame and "plug in" for the radios (you can tell how this is related now...).  I have two radios I can simply swap in and out.  One is a Sound Stream AM/FM cassette, the other is the original AM pushbutton radio that came with the car.   A third will soon be a 1970's vintage 8-track.   The plug-in around the radio connects to the frame in the car using a multi-pin connector to carry +12V, ground, stereo left/right  front and back, antenna power, etc.
   Now, the problem is that I used a set of connectors from a Tek 500 plug-in, as I had a few junkers at the time (and I was a bit clueless).   Clearly, these are a bit more valuable to me now.
   The question then, is are there any very *similar* connectors to the Amphenol blue Tek 500 plug in connectors that would serve in a similar capacity?   Prefereably they would be commonly available, and be a relatively simple swap for bot the male and female versions.   That would allow me to pull the two males and one female out of my radios and use them to fix the damaged connectors on a couple of Tek 500 plug-ins that need them.   And I'd have something a bit more replaceable for the radios.   I need at least as many pins because they are all used!

  Thanks for the Ideas in advance,  Dan


Re: 2440 deal

Robert Simpson
 

Bob (LA) if you really want it, my other Daughter has family down there and goes occasionally.
Bob

Anyone else also interested?


Re: 2440 deal

Bob Albert
 

Come to think of it, my friend W6TOM in your area has helped me similarly in the past.  Maybe you can connect with him and see if he is planning to go to the hamfest Saturday in Santa Barbara.  If so, he should be willing to bring it down.
Bob818 894-2887

On Tuesday, August 6, 2019, 06:35:55 PM PDT, Robert Simpson via Groups.Io <go_boating_fast=yahoo.com@groups.io> wrote:

If I shipped it, I double box ( as those who bought o_scope CRTs know). so at 30 Lbs (item plus packing) boxed dimension 24x18x12. The USPS calculator ground delivery shows $80 from 95630 to Bangor Maine (worst case) Cheaper of course to LA or other (LA would be $45).
Bob


Re: 2440 deal

Bob Albert
 

Well I was hoping to meet and pick it up but that doesn't appear to be an option.  So my investment jumps to $95.  I probably shouldn't do it.
Bob

On Tuesday, August 6, 2019, 06:35:55 PM PDT, Robert Simpson via Groups.Io <go_boating_fast=yahoo.com@groups.io> wrote:

If I shipped it, I double box ( as those who bought o_scope CRTs know). so at 30 Lbs (item plus packing) boxed dimension 24x18x12. The USPS calculator ground delivery shows $80 from 95630 to Bangor Maine (worst case) Cheaper of course to LA or other (LA would be $45).
Bob


Re: 2440 deal

Robert Simpson
 

If I shipped it, I double box ( as those who bought o_scope CRTs know). so at 30 Lbs (item plus packing) boxed dimension 24x18x12. The USPS calculator ground delivery shows $80 from 95630 to Bangor Maine (worst case) Cheaper of course to LA or other (LA would be $45).
Bob


Re: Simulator

Harvey White
 

This is a part of an off line discussion.  JR has a 465B with the trace off to the right.  From what I can tell, the CRT is ok, and most of the horizontal amp except for the differential stage is more or less (pot adjustable) in balance.

JR simulated the circuit with one simulator, I simulated the first stages with another.  His simulation doesn't seem to agree with reality (let alone the schematic voltages).  Mine (Multisim Blue, since discontinued) agrees with the schematic, but not reality as measured.  We're trying to get the first stage (differential, emitter coupled) to balance.  Having replaced most of the transistors, it's not happening, so he's doing the measuring, and I'm doing the "try to figure out what's going on" part.

Harvey.

Feel free to reply and comment off list.

On 8/6/2019 10:07 AM, Tony Fleming wrote:
Can you point me to the place where you talk about it?
Thank you!
Tony

On Mon, Aug 5, 2019 at 11:19 PM Abc Xyz <yawrdanza@gmail.com> wrote:

Harvey,

Did you get s chance to compare my Simulator Voltages with your Simulator
Voltages yet?
JR





Re: 2440 deal

Bob Albert
 

So buy all three and let us all benefit.  I am willing to pay for gasoline cost to bring it to wherever, such as Santa Barbara.
Bob818 894-2887 after 3PM

On Tuesday, August 6, 2019, 05:28:38 PM PDT, Robert Simpson via Groups.Io <go_boating_fast=yahoo.com@groups.io> wrote:

OK,
I am actually going to ask my daughter who works nearby to try and get one. I actually live in Folsom CA, but she has helped me get stuff before.
Bob


Re: 2440 deal

Robert Simpson
 

OK,
I am actually going to ask my daughter who works nearby to try and get one. I actually live in Folsom CA, but she has helped me get stuff before.
Bob


Re: O.T. question on MoVs

Mark Goldberg
 

I am not sure how to test them non-destructively. I only buy parts from
real distributors, so you know what you are getting. Much of the stuff from
Amazon / Aliexpess / Ebay, especially from international sources is
counterfeit or bad. Markings don't mean anything either as they paint those
on fakes too.

Regards,

Mark

On Tue, Aug 6, 2019 at 3:38 PM Ancel <protofabtt@gmail.com> wrote:

Hi all,
Somewhat off topic power supply related.
I got some MoVs from aliexpress which I ordered to use in series to
protect a 277VAC, 90mA mains supply from high transients.

They ought to be a pair of 270VAC units in series, shorted across the 2
wire AC supply from high transients.
07D271 type part. They capacitive coupled design (2.2uf, 450VAC
polypropylene Caps on both lines) allow for 900VAC transient operation
without issue.
But ..they shipped unmarked and the supplier is not responding. So it
seems I need to do a test bed to validate their function.
Any advice on the approach?





Re: O.T. question on MoVs

Brad Thompson
 

Ancel wrote on 8/6/2019 6:38 PM:

Hi all,
Somewhat off topic power supply related.
I got some MoVs from aliexpress which I ordered to use in series to protect a 277VAC, 90mA mains supply from high transients.

They ought to be a pair of 270VAC units in series, shorted across the 2 wire AC supply from high transients.
07D271 type part. They capacitive coupled design (2.2uf, 450VAC polypropylene Caps on both lines) allow for 900VAC transient operation without issue.
But ..they shipped unmarked and the supplier is not responding. So it seems I need to do a test bed to validate their function.
Any advice on the approach?
Hello, Ancel--

Since there are no markings --including (I assume) any safety agency markings, I'd be strongly tempted to
demand a refund from the seller. You may have received counterfeits or rejects.

 Purchase labeled replacements from an authorized seller to be relatively certain that you're getting
reliable and predictable parts. Here's an article describing selection of MOVs:

https://www.electronicdesign.com/power/select-right-varistors-overvoltage-circuit-protection

If you're intent on determining what parts you received, you can use a curve tracer to examine
the MOV's breakover voltage (the knee of the voltage versus current characteristic) at a
specified low current, perhaps 1 mA for smaller sizes).

Note that MOVs have a service life because the voltage-clamping mechanism relies on
degradation of the oxide layer surrounding the metal granules sintered together. After
repeated overvoltages, the granules fuse together and the MOV conducts heavily.
MOVs may fail in short-circuit mode. Thus, there should be fuses or circuit breakers
between the incoming AC power and the MOVs.

To be safe, always buy safety-related and branded components from legitimate sources.

73--

Brad  AA1IP


Re: Tekmate 2402 rebuild and programming

Tony Fleming
 

On Tue, Aug 6, 2019 at 11:22 AM A Rhodes <rhodes@comcast.net> wrote:

I have uploaded to Github a few different repositories under the user name
"Tek-User".

You can use google for "github two-user".

There are 4 project repositories. One on writing new software for the
2402.

Another on repairing an old 2402 and getting it working. And then
upgrading the 2402 to a 133MHz 586 EBX motherboard and the complexities
that are encountered.

Another project ports the new programming from the first project listed
here and placing it on an arduino. A tiny arduino can largely replace the
entire 2402 as an embedded system with the user interface through the
scope.

I have found and placed in these repositories various software packages
relating to the 2402.

One software package I have NOT found is the Tektronix "Program
Development Software". This apparently has the source code used for the
"dso-sh" and "dos-app" software packages provided by Tektronix. I have
searched for the development software by thoroughly googling all variations
and themes of this topic and found nothing.

Does anyone here have any leads for the Program Development Software?

-Tony




O.T. question on MoVs

 

Hi all,
Somewhat off topic power supply related.
I got some MoVs from aliexpress which I ordered to use in series to protect a 277VAC, 90mA mains supply from high transients.

They ought to be a pair of 270VAC units in series, shorted across the 2 wire AC supply from high transients.
07D271 type part. They capacitive coupled design (2.2uf, 450VAC polypropylene Caps on both lines) allow for 900VAC transient operation without issue.
But ..they shipped unmarked and the supplier is not responding. So it seems I need to do a test bed to validate their function.
Any advice on the approach?


Re: General Radio 874 Connector, inner conductor "bendies"

Richard Knoppow
 

I looked at a couple of 874 s just now. The tips of the small center contacts are pointed and slightly tapered toward the center. The larger of the center contacts are tapered toward the inside and slightly bent outward so that the opposing contacts slide over each other and form a continuous tube. Its somewhat the same as the outside contacts.
While the photo may be an optical illusion it does not look right. I don't think the connector was twisted but someone may have put a 274 banana plug into it and bent it. The 274 _can_ be used on an 874 but one must be careful not to stress it. The design is such that the outer shell makes contact first and pretty much prevents the mating plugs from being twisted.
The 874 is a pretty good connector but has the disadvantage of not having a precise reference plane. They can act as a short sliding line. Even when locked the reference plane is uncertain.

On 8/6/2019 2:44 PM, Roy Thistle wrote:
Hi All:
Apologies, if this has been covered (there are a lot of posts on 874!).. but the picture on Tekwiki of the GR-874 (the one with the plug facing the viewer... so you can see into it)… well that picture shows two of the leaves of the center conductor, bent in at the corners, and so having little "bendies" barbs, or tangs. (You have to see the picture!).
http://w140.com/tekwiki/wiki/GR-874_connector.
My initial question is… Is that normal, or is the center conductor of the connector damaged? (You can see a bit of those "bendies" on the leaves of the outer conductor, in the picture, too.) My initial guess is the matching, inserter GR-874, after being rotated, and mated, has damaged the insertee? If so, how does the mated pair maintain 50 ohms?
Best regards and wishes.
Roy
--
Richard Knoppow
dickburk@ix.netcom.com
WB6KBL


Re: General Radio 874 Connector, inner conductor "bendies"

Merchison Burke
 

I don't see any bending. What I see are the sharp edges have been chamfered which makes it easy to mate with another GR874 connector. All my GR874 connectors look the same.

On 2019-Aug-06 5:44 PM, Roy Thistle wrote:
Hi All:
Apologies, if this has been covered (there are a lot of posts on 874!).. but the picture on Tekwiki of the GR-874 (the one with the plug facing the viewer... so you can see into it)??? well that picture shows two of the leaves of the center conductor, bent in at the corners, and so having little "bendies" barbs, or tangs. (You have to see the picture!).
http://w140.com/tekwiki/wiki/GR-874_connector.
My initial question is??? Is that normal, or is the center conductor of the connector damaged? (You can see a bit of those "bendies" on the leaves of the outer conductor, in the picture, too.) My initial guess is the matching, inserter GR-874, after being rotated, and mated, has damaged the insertee? If so, how does the mated pair maintain 50 ohms?
Best regards and wishes.
Roy



---
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Re: General Radio 874 Connector, inner conductor "bendies"

george edmonds
 

Hi Roy

These are hermaphrodite connectors and the picture that you refer to does not appear damaged.

73 George G6HIG On Tuesday, August 6, 2019, 10:44:41 PM GMT+1, Roy Thistle <roy.thistle@mail.utoronto.ca> wrote:

Hi All:
Apologies, if this has been covered (there are a lot of posts on 874!).. but the picture on Tekwiki of the GR-874 (the one with the plug facing the viewer... so you can see into it)… well that picture shows two of the leaves of the center conductor, bent in at the corners, and so having little "bendies" barbs, or tangs. (You have to see the picture!).
http://w140.com/tekwiki/wiki/GR-874_connector.
My initial question is… Is that normal, or is the center conductor of the connector damaged? (You can see a bit of those "bendies" on the leaves of the outer conductor, in the picture, too.) My initial guess is the matching, inserter GR-874, after being rotated, and mated, has damaged the insertee?  If so, how does the mated pair maintain 50 ohms?
Best regards and wishes.
Roy

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