Mounting and dismounting curve tracer 177 fixture


Gary Robert Bosworth
 

Does anyone know how to mount and dismount the 177 test fixture into the 577 curve tracer? Is there a locking mechanism?

Gary


Mlynch001
 

Gary,

Mine just pulls out by grasping the two little knobs on the front and giving it a tug. Pops right out.

--
Michael Lynch
Dardanelle, AR


Bob Koller <testtech@...>
 

Pulls out, but DO NOT pull on the Vertical Current knob , it has a plastic coupling and you will break it!
There can be two sources of friction preventing easy removal; there are short screws securing the cover underneath the instrument. If too long, they will drive into the plugin. Also, sometime the lower cabinet skirts are adjusted too close.


 

Hi Gary,

Oh boy, I once spend hours trying to get the 177 out of my first 577.
Turn the 577 over. There are two screws near the front of the 577 bottom panel that screw in to the 177 to hold it in place. I suspect they are there to prevent the 177 from being easily stolen. The 177 will not budge until you remove them.
Then you can pull it out by the two ground lugs on either side of the front of the 177. At first it may seem stuck but that is because the connector contacts of the 577 holds the PC Board of the 177 pretty tight.

Dennis Tillman W7PF

-----Original Message-----
From: Gary Robert Bosworth
Sent: Friday, January 24, 2020 9:27 AM
To: TekScopes@groups.io
Subject: [TekScopes] Mounting and dismounting curve tracer 177 fixture

Does anyone know how to mount and dismount the 177 test fixture into the 577 curve tracer? Is there a locking mechanism?

Gary




--
Dennis Tillman W7PF
TekScopes Moderator


Mlynch001
 

Dennis,

I suppose mine is missing the screws, since mine just pulls out. Never looked under it for any sort of retainer. Do you feel that these screws are essential? If so, I will install them.

--
Michael Lynch
Dardanelle, AR


 

Hi Michael,
No not for a personal 577. They might have been there to prevent the 177 from ever getting loose or as a simple precaution to prevent people from taking the 177.
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Mlynch001
Sent: Friday, January 24, 2020 11:18 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Mounting and dismounting curve tracer 177 fixture

Dennis,

I suppose mine is missing the screws, since mine just pulls out. Never looked under it for any sort of retainer. Do you feel that these screws are essential? If so, I will install them.

--
Michael Lynch
Dardanelle, AR




--
Dennis Tillman W7PF
TekScopes Moderator


Bob Koller <testtech@...>
 

The screws were not, from the factory, intended to retain the 177. Often someone would put the wrong screws in the forward two holes thereby effectively locking the plugin in place. I suppose that at some company, they did purposely install longer screws to keep the 177 from being removed,
The same thing can happen on the 576.

Again, don't use the Vertical atten knob as a finger hold!!


Mlynch001
 

On Fri, Jan 24, 2020 at 02:48 PM, Bob Koller wrote:


The screws were not, from the factory, intended to retain the 177. Often
someone would put the wrong screws in the forward two holes thereby
effectively locking the plugin in place. I suppose that at some company, they
did purposely install longer screws to keep the 177 from being removed,
The same thing can happen on the 576.

Again, don't use the Vertical atten knob as a finger hold!!
Bob,

The 576 has 2 thumbscrews that hold the test fixture in place. When I got my 577, I thought that those 2 knobs on the front were thumbscrews, like the 576. Mine were both just spinning loose and i had to take the 177 apart to access the screws inside and tighten the loose knobs. The knobs are just simple handholds, so that you have something to pull on besides the fragile control knobs.

--
Michael Lynch
Dardanelle, AR


Bob Koller <testtech@...>
 

Michael,

Yes, I am very familiar with the 576, having worked on many dozens of them. The bottom cover screws if too long, can bind with the the test fixture.
Interestingly, there were some 177's that did not have the "pull knobs", nor the holes for them. I just had one in for repair in that configuration.


Dave Voorhis
 

On 24 Jan 2020, at 22:36, Bob Koller via Groups.Io <testtech=yahoo.com@groups.io> wrote:

Yes, I am very familiar with the 576, having worked on many dozens of them. The bottom cover screws if too long, can bind with the the test fixture.
Interestingly, there were some 177's that did not have the "pull knobs", nor the holes for them. I just had one in for repair in that configuration.
Yes, my 577/177 has no pull knobs.


Mlynch001
 

Bob,

Have you ever seen a 577/177 with a switch guard? I have heard rumors that some late model units had a loop guard over the switch to stop from getting the switch handle broken off.

--
Michael Lynch
Dardanelle, AR


 

Hi Dave,
I always thought it was the early 177s that did not have the knobs to pull
it out of the 577.
Dennis Tillman W7PF

-----Original Message-----
From: Dave Voorhis
Sent: Friday, January 24, 2020 2:59 PM
Subject: Re: [TekScopes] Mounting and dismounting curve tracer 177 fixture

On 24 Jan 2020, at 22:36, Bob Koller via Groups.Io
<testtech=yahoo.com@groups.io> wrote:

Yes, I am very familiar with the 576, having worked on many dozens of
them. The bottom cover screws if too long, can bind with the the test
fixture.
Interestingly, there were some 177's that did not have the "pull knobs",
nor the holes for them. I just had one in for repair in that configuration.

Yes, my 577/177 has no pull knobs.




--
Dennis Tillman W7PF
TekScopes Moderator


 

I have seen a picture of one. I often thought about making them myself. I have broken off those knobs several times. I am surprised Tek allowed that to be exposed. It begs to be snapped off.

The guard is just a simple U shaped piece of anodized aluminum with a hole in it. You unscrew the threaded nut holding the switch, slip the guard over the neck of the switch and screw the nut back on.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Mlynch001
Sent: Friday, January 24, 2020 5:15 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Mounting and dismounting curve tracer 177 fixture

Bob,

Have you ever seen a 577/177 with a switch guard? I have heard rumors that some late model units had a loop guard over the switch to stop from getting the switch handle broken off.

--
Michael Lynch
Dardanelle, AR





--
Dennis Tillman W7PF
TekScopes Moderator


Mlynch001
 

I may make one for mine. I am careful, but the handle is about as exposed as anything can be. I too often wondered why TEK did not have a guard on them from Job#1. Probably would have added 10 cents to the cost?? I had to replace the handle in my switch, someone had sheared the metal lever off right near the base. Almost impossible to switch and no switch to be had. I was able to find a similar switch, one with the same handle and mechanisim, disassemble both switches and replace just the bat handle and metal lever. Not a simple task, good thing is that I found a broken solder joint on one of the pads on the board for the switch, so that probably saved me some issues down the road.

--
Michael Lynch
Dardanelle, AR


Chuck Harris <cfharris@...>
 

They could have killed two birds with one stone if they simply
put a "U" shaped pull handle on the front of the porch. Then
they would have had a way to remove the porch, and the handle
would have protected the switch, without getting in its way.

-Chuck Harris

Mlynch001 wrote:

I may make one for mine. I am careful, but the handle is about as exposed as anything can be. I too often wondered why TEK did not have a guard on them from Job#1. Probably would have added 10 cents to the cost?? I had to replace the handle in my switch, someone had sheared the metal lever off right near the base. Almost impossible to switch and no switch to be had. I was able to find a similar switch, one with the same handle and mechanisim, disassemble both switches and replace just the bat handle and metal lever. Not a simple task, good thing is that I found a broken solder joint on one of the pads on the board for the switch, so that probably saved me some issues down the road.


Gary Robert Bosworth
 

Thank you for your assistance. Sure enough, there were 2 screws on the
bottom that locked the 177 in place. I never would have known about this
locking mechanism without your help. Once I removed the screws, the 177
slid out easily. Thank you again for your help.

Gary

On Fri, Jan 24, 2020 at 10:02 AM Dennis Tillman W7PF <dennis@ridesoft.com>
wrote:

Hi Gary,

Oh boy, I once spend hours trying to get the 177 out of my first 577.
Turn the 577 over. There are two screws near the front of the 577 bottom
panel that screw in to the 177 to hold it in place. I suspect they are
there to prevent the 177 from being easily stolen. The 177 will not budge
until you remove them.
Then you can pull it out by the two ground lugs on either side of the
front of the 177. At first it may seem stuck but that is because the
connector contacts of the 577 holds the PC Board of the 177 pretty tight.

Dennis Tillman W7PF

-----Original Message-----
From: Gary Robert Bosworth
Sent: Friday, January 24, 2020 9:27 AM
To: TekScopes@groups.io
Subject: [TekScopes] Mounting and dismounting curve tracer 177 fixture

Does anyone know how to mount and dismount the 177 test fixture into the
577 curve tracer? Is there a locking mechanism?

Gary




--
Dennis Tillman W7PF
TekScopes Moderator



--
Gary Robert Bosworth
grbosworth@gmail.com
Tel: 310-317-2247


Chuck Harris <cfharris@...>
 

To paraphrase the 577 manual on gaining access to the 577's plugin
connector for replacement:

... remove the 4 screws from the bottom cover of the scope. Pay
note that two of the screws are shorter than the rest, and must
be placed in the front two holes...

It seems likely that some technician, at some point in the scope's
life, removed the bottom cover plate from the scope, and scrambled
the screws... thus locking the plugin into the scope.

-Chuck Harris

Gary Robert Bosworth wrote:

Thank you for your assistance. Sure enough, there were 2 screws on the
bottom that locked the 177 in place. I never would have known about this
locking mechanism without your help. Once I removed the screws, the 177
slid out easily. Thank you again for your help.

Gary

On Fri, Jan 24, 2020 at 10:02 AM Dennis Tillman W7PF <dennis@ridesoft.com>
wrote:

Hi Gary,

Oh boy, I once spend hours trying to get the 177 out of my first 577.
Turn the 577 over. There are two screws near the front of the 577 bottom
panel that screw in to the 177 to hold it in place. I suspect they are
there to prevent the 177 from being easily stolen. The 177 will not budge
until you remove them.
Then you can pull it out by the two ground lugs on either side of the
front of the 177. At first it may seem stuck but that is because the
connector contacts of the 577 holds the PC Board of the 177 pretty tight.

Dennis Tillman W7PF

-----Original Message-----
From: Gary Robert Bosworth
Sent: Friday, January 24, 2020 9:27 AM
To: TekScopes@groups.io
Subject: [TekScopes] Mounting and dismounting curve tracer 177 fixture

Does anyone know how to mount and dismount the 177 test fixture into the
577 curve tracer? Is there a locking mechanism?

Gary




--
Dennis Tillman W7PF
TekScopes Moderator