Help!!

I was wondering if anyone has a Tek 547 scope that is being used for parts?

I am in need of the tunnel diodes used in the A & B trigger circuits. The General Electric P/N is TD 253. The Tektronix number is 152-154. Later serial numbers used the 152-0140-01, which is also a 10ma tunnel diode. This one may work as well.

Alternately, does anyone know where I can buy these diodes? I have done, what I believe to be an extensive internet search to no avail.

I am troubleshooting a problem with the A Timebase trigger. If anyone is interested in how I came to suspect the tunnel diode let me know. Maybe I am wrong and the problem is elsewhere.

Any and all help would be greatly appreciated.
This is a great scope and it deserves to live!

Gary

:Help!!
:
:I was wondering if anyone has a Tek 547 scope that is being used for parts?
:
:I am in need of the tunnel diodes used in the A & B trigger circuits. The General Electric P/N is TD 253. The Tektronix number is 152-154. Later serial numbers used the 152-0140-01, which is also a 10ma tunnel diode. This one may work as well.
:
:Alternately, does anyone know where I can buy these diodes? I have done, what I believe to be an extensive internet search to no avail.
:
:I am troubleshooting a problem with the A Timebase trigger. If anyone is interested in how I came to suspect the tunnel diode let me know. Maybe I am wrong and the problem is elsewhere.
:
:Any and all help would be greatly appreciated.
:This is a great scope and it deserves to live!
:
:Gary
:
So, my scope has an extra TD253 tunnel diode where a TD3A should be. If you can find a good TD3A you can have my diode. The TD3A is the small black diode with the flat gold leads.
Johnnysan-

::Help!!
::
::I was wondering if anyone has a Tek 547 scope that is being used for parts?
::
::I am in need of the tunnel diodes used in the A & B trigger circuits. The General Electric P/N is TD 253. The Tektronix number is 152-154. Later serial numbers used the 152-0140-01, which is also a 10ma tunnel diode. This one may work as well.
::
::Alternately, does anyone know where I can buy these diodes? I have done, what I believe to be an extensive internet search to no avail.
::
::I am troubleshooting a problem with the A Timebase trigger. If anyone is interested in how I came to suspect the tunnel diode let me know. Maybe I am wrong and the problem is elsewhere.
::
::Any and all help would be greatly appreciated.
::This is a great scope and it deserves to live!
::
::Gary
::
:
:
:
:I also have a 547 and have a need for the TD3A tunnel diode. Someone previous to me had replaced this diode with the other type (TD253). As it turns out, the whole problem was just a bad connection at one of the transistor sockets (Q 244, 234 or 284). I was getting triggering with the B time base, but not A. Once I corrected the poor connection at the transistor lead, I got triggering on A, but the B time base no longer triggers properly. I believe it is because of the difference in tunnel diodes. They had also changed some transistors, but used the correct replacements. I have been waiting for a junker 547 to become available; I have sampling and spectrum analyzer plug-ins I want to use.
:So, my scope has an extra TD253 tunnel diode where a TD3A should be. If you can find a good TD3A you can have my diode. The TD3A is the small black diode with the flat gold leads.
:Johnnysan-
:
:Johnnysan,

Thanks for the info.

The bad connection at the transistor socket, was it corrosion in the socket pins of a bad solder connection underneath?

The B Timebase trigger on my scope works fine, which helped me trouble shoot the A Timebase trigger. One thing I've noticed is that the calibration of the trigger circuit is critical and somewhat sensitive. Did you calibrate the B Trigger circuit after the diode was replaced?
:

Gary
:

:::Help!!
:::
:::I was wondering if anyone has a Tek 547 scope that is being used for parts?
:::
:::I am in need of the tunnel diodes used in the A & B trigger circuits. The General Electric P/N is TD 253. The Tektronix number is 152-154. Later serial numbers used the 152-0140-01, which is also a 10ma tunnel diode. This one may work as well.
:::
:::Alternately, does anyone know where I can buy these diodes? I have done, what I believe to be an extensive internet search to no avail.
:::
:::I am troubleshooting a problem with the A Timebase trigger. If anyone is interested in how I came to suspect the tunnel diode let me know. Maybe I am wrong and the problem is elsewhere.
:::
:::Any and all help would be greatly appreciated.
:::This is a great scope and it deserves to live!
:::
:::Gary
:::
::
::
::
::I also have a 547 and have a need for the TD3A tunnel diode. Someone previous to me had replaced this diode with the other type (TD253). As it turns out, the whole problem was just a bad connection at one of the transistor sockets (Q 244, 234 or 284). I was getting triggering with the B time base, but not A. Once I corrected the poor connection at the transistor lead, I got triggering on A, but the B time base no longer triggers properly. I believe it is because of the difference in tunnel diodes. They had also changed some transistors, but used the correct replacements. I have been waiting for a junker 547 to become available; I have sampling and spectrum analyzer plug-ins I want to use.
::So, my scope has an extra TD253 tunnel diode where a TD3A should be. If you can find a good TD3A you can have my diode. The TD3A is the small black diode with the flat gold leads.
::Johnnysan-
::
::Johnnysan,
:
:Thanks for the info.
:
:The bad connection at the transistor socket, was it corrosion in the socket pins of a bad solder connection underneath?
:
:The B Timebase trigger on my scope works fine, which helped me trouble shoot the A Timebase trigger. One thing I've noticed is that the calibration of the trigger circuit is critical and somewhat sensitive. Did you calibrate the B Trigger circuit after the diode was replaced?
::
:
:Gary
::
:
I did not perform a calibration; maybe I should try that, but I really want to have the right tunnel diode in there first. The transistor socket that was bad had contacts that were too wide; I just pulled the transistor and bent the leads over and doubled them, then re-inserted the transistor. Replacing the socket would have been a big job.
Johnnysan-

::::Help!!
::::
::::I was wondering if anyone has a Tek 547 scope that is being used for parts?
::::
::::I am in need of the tunnel diodes used in the A & B trigger circuits. The General Electric P/N is TD 253. The Tektronix number is 152-154. Later serial numbers used the 152-0140-01, which is also a 10ma tunnel diode. This one may work as well.
::::
::::Alternately, does anyone know where I can buy these diodes? I have done, what I believe to be an extensive internet search to no avail.
::::
::::I am troubleshooting a problem with the A Timebase trigger. If anyone is interested in how I came to suspect the tunnel diode let me know. Maybe I am wrong and the problem is elsewhere.
::::
::::Any and all help would be greatly appreciated.
::::This is a great scope and it deserves to live!
::::
::::Gary
::::
:::
:::
:::
:::I also have a 547 and have a need for the TD3A tunnel diode. Someone previous to me had replaced this diode with the other type (TD253). As it turns out, the whole problem was just a bad connection at one of the transistor sockets (Q 244, 234 or 284). I was getting triggering with the B time base, but not A. Once I corrected the poor connection at the transistor lead, I got triggering on A, but the B time base no longer triggers properly. I believe it is because of the difference in tunnel diodes. They had also changed some transistors, but used the correct replacements. I have been waiting for a junker 547 to become available; I have sampling and spectrum analyzer plug-ins I want to use.
:::So, my scope has an extra TD253 tunnel diode where a TD3A should be. If you can find a good TD3A you can have my diode. The TD3A is the small black diode with the flat gold leads.
:::Johnnysan-
:::
:::Johnnysan,
::
::Thanks for the info.
::
::The bad connection at the transistor socket, was it corrosion in the socket pins of a bad solder connection underneath?
::
::The B Timebase trigger on my scope works fine, which helped me trouble shoot the A Timebase trigger. One thing I've noticed is that the calibration of the trigger circuit is critical and somewhat sensitive. Did you calibrate the B Trigger circuit after the diode was replaced?
:::
::
::Gary
:::
::
:
:
:I did not perform a calibration; maybe I should try that, but I really want to have the right tunnel diode in there first. The transistor socket that was bad had contacts that were too wide; I just pulled the transistor and bent the leads over and doubled them, then re-inserted the transistor. Replacing the socket would have been a big job.
:Johnnysan-
:
:Johnnysan,

While looking for tunnel diodes on the internet I suddenly realized that I have a Tek 585 that I have use for parts. Then it dawned on me that maybe it had a tunnel diode in the trigger circuit. I checked the manyual and wouldn't ya know it, it did. The part number is different than the one used in the 547 but the specs are similar, in that it is also a 10ma tunnel diode. I put it into the A Trigger circuit of my 457, did the trigger circuit calibration and it works great. What a relief! I was beginning to think that my 547 was going to end up collecting dust in the corner of my shop.

It just goes to show you NEVER THROW ANYTHING OUT!

Regarding your scope, you might want to try to calibrate the trigger circuit. It is a very simple procedure and may be all your scope needs. Bama has the manual if you don't already have it.

Thanks for your help and good luck with the calibration.

Gary
:
:

:::::Help!!
:::::
:::::I was wondering if anyone has a Tek 547 scope that is being used for parts?
:::::
:::::I am in need of the tunnel diodes used in the A & B trigger circuits. The General Electric P/N is TD 253. The Tektronix number is 152-154. Later serial numbers used the 152-0140-01, which is also a 10ma tunnel diode. This one may work as well.
:::::
:::::Alternately, does anyone know where I can buy these diodes? I have done, what I believe to be an extensive internet search to no avail.
:::::
:::::I am troubleshooting a problem with the A Timebase trigger. If anyone is interested in how I came to suspect the tunnel diode let me know. Maybe I am wrong and the problem is elsewhere.
:::::
:::::Any and all help would be greatly appreciated.
:::::This is a great scope and it deserves to live!
:::::
:::::Gary
:::::
::::
::::
::::
::::I also have a 547 and have a need for the TD3A tunnel diode. Someone previous to me had replaced this diode with the other type (TD253). As it turns out, the whole problem was just a bad connection at one of the transistor sockets (Q 244, 234 or 284). I was getting triggering with the B time base, but not A. Once I corrected the poor connection at the transistor lead, I got triggering on A, but the B time base no longer triggers properly. I believe it is because of the difference in tunnel diodes. They had also changed some transistors, but used the correct replacements. I have been waiting for a junker 547 to become available; I have sampling and spectrum analyzer plug-ins I want to use.
::::So, my scope has an extra TD253 tunnel diode where a TD3A should be. If you can find a good TD3A you can have my diode. The TD3A is the small black diode with the flat gold leads.
::::Johnnysan-
::::
::::Johnnysan,
:::
:::Thanks for the info.
:::
:::The bad connection at the transistor socket, was it corrosion in the socket pins of a bad solder connection underneath?
:::
:::The B Timebase trigger on my scope works fine, which helped me trouble shoot the A Timebase trigger. One thing I've noticed is that the calibration of the trigger circuit is critical and somewhat sensitive. Did you calibrate the B Trigger circuit after the diode was replaced?
::::
:::
:::Gary
::::
:::
::
::
::I did not perform a calibration; maybe I should try that, but I really want to have the right tunnel diode in there first. The transistor socket that was bad had contacts that were too wide; I just pulled the transistor and bent the leads over and doubled them, then re-inserted the transistor. Replacing the socket would have been a big job.
::Johnnysan-
::
::Johnnysan,
:
:While looking for tunnel diodes on the internet I suddenly realized that I have a Tek 585 that I have use for parts. Then it dawned on me that maybe it had a tunnel diode in the trigger circuit. I checked the manyual and wouldn't ya know it, it did. The part number is different than the one used in the 547 but the specs are similar, in that it is also a 10ma tunnel diode. I put it into the A Trigger circuit of my 457, did the trigger circuit calibration and it works great. What a relief! I was beginning to think that my 547 was going to end up collecting dust in the corner of my shop.
:
:It just goes to show you NEVER THROW ANYTHING OUT!
:
:Regarding your scope, you might want to try to calibrate the trigger circuit. It is a very simple procedure and may be all your scope needs. Bama has the manual if you don't already have it.
:
:Thanks for your help and good luck with the calibration.
:
:Gary
::
::
:
Thanks Gary, I have the manual. I will eventually get back to the 547 and do a calibration.
Johnnysan-

:Help!!
:
:I was wondering if anyone has a Tek 547 scope that is being used for parts?
:
:I am in need of the tunnel diodes used in the A & B trigger circuits. The General Electric P/N is TD 253. The Tektronix number is 152-154. Later serial numbers used the 152-0140-01, which is also a 10ma tunnel diode. This one may work as well.
:
:Alternately, does anyone know where I can buy these diodes? I have done, what I believe to be an extensive internet search to no avail.
:
:I am troubleshooting a problem with the A Timebase trigger. If anyone is interested in how I came to suspect the tunnel diode let me know. Maybe I am wrong and the problem is elsewhere.
:
:Any and all help would be greatly appreciated.
:This is a great scope and it deserves to live!
:
:Gary
:
Hello Gary
Are you still looking for the TD for the Tek 547.
I have a Tek 547 for parts.
Henry

:Help!!
:
:I was wondering if anyone has a Tek 547 scope that is being used for parts?
:
:I am in need of the tunnel diodes used in the A & B trigger circuits. The General Electric P/N is TD 253. The Tektronix number is 152-154. Later serial numbers used the 152-0140-01, which is also a 10ma tunnel diode. This one may work as well.
:
:Alternately, does anyone know where I can buy these diodes? I have done, what I believe to be an extensive internet search to no avail.
:
:I am troubleshooting a problem with the A Timebase trigger. If anyone is interested in how I came to suspect the tunnel diode let me know. Maybe I am wrong and the problem is elsewhere.
:
:Any and all help would be greatly appreciated.
:This is a great scope and it deserves to live!
:
:Gary
:
Did a lot of work on Tek scopes years ago. The TD was used in many models and the only one that was fussy was the 585. TD's were rarely the problem but we usually used 1N3719 as replacements in all the 500 series scopes. There is a whole family of TD's starting at 1N3714 that would be acceptable but check the specs against what you have. Here is some data and some current web sites to help you out.

Bob

General Electric P/N is TD 253 Tektronix number is

152-154, use 152-0140-01 or 1N3719

TD253A
General Purpose Tunnel Diode
General Electric Solid State
Diodes
V(f)(V) Forward Voltage @Ipeak=570m
Ipeak Max. (A)=10m
Peak Current Tol. (A)=1.0m
V(P) (V) Peak-Point Voltage=80m
V(V) (V) Valley-Point Voltage=410m
Ratio Ipeak/Ivalley Min.=8.0
I(F) Max. (A) Forward Current=10m
r(s) Max. (Ohms) Series Res.=2.0
L(s) Max.(H),Series Inductance=1.5n
C(t) Max.(F) Total Capacitance=5.0p
P(D) Max.(W) Power Dissipation=7.0m
Semiconductor Material=Germanium
Status=Discontinued

http://www.americanmicrosemi.com/information/tutorial

/index.php?t_id=11

http://www.mpulsemw.com/Tunnel_Diode.htm

http://www.digitroncorp.com/parts/part_details.asp?/p

art/1N3719

http://www.4starelectronics.com/part_detail/1N3719.ht

ml

As for Digikey and Mouser, not sure if they carry the TD's.

::Help!!
::
::I was wondering if anyone has a Tek 547 scope that is being used for parts?
::
::I am in need of the tunnel diodes used in the A & B trigger circuits. The General Electric P/N is TD 253. The Tektronix number is 152-154. Later serial numbers used the 152-0140-01, which is also a 10ma tunnel diode. This one may work as well.
::
::Alternately, does anyone know where I can buy these diodes? I have done, what I believe to be an extensive internet search to no avail.
::
::I am troubleshooting a problem with the A Timebase trigger. If anyone is interested in how I came to suspect the tunnel diode let me know. Maybe I am wrong and the problem is elsewhere.
::
::Any and all help would be greatly appreciated.
::This is a great scope and it deserves to live!
::
::Gary
::
:
:Hi Gary,
: Did a lot of work on Tek scopes years ago. The TD was used in many models and the only one that was fussy was the 585. TD's were rarely the problem but we usually used 1N3719 as replacements in all the 500 series scopes. There is a whole family of TD's starting at 1N3714 that would be acceptable but check the specs against what you have. Here is some data and some current web sites to help you out.
:
:Bob
:
:General Electric P/N is TD 253 Tektronix number is
:
:152-154, use 152-0140-01 or 1N3719
:
:TD253A
:General Purpose Tunnel Diode
:General Electric Solid State
:Diodes
:V(f)(V) Forward Voltage @Ipeak=570m
:Ipeak Max. (A)=10m
:Peak Current Tol. (A)=1.0m
:V(P) (V) Peak-Point Voltage=80m
:V(V) (V) Valley-Point Voltage=410m
:Ratio Ipeak/Ivalley Min.=8.0
:I(F) Max. (A) Forward Current=10m
:r(s) Max. (Ohms) Series Res.=2.0
:L(s) Max.(H),Series Inductance=1.5n
:C(t) Max.(F) Total Capacitance=5.0p
:P(D) Max.(W) Power Dissipation=7.0m
:Semiconductor Material=Germanium
:Status=Discontinued
:
:
:http://www.americanmicrosemi.com/information/tutorial
:
:/index.php?t_id=11
:
:http://www.mpulsemw.com/Tunnel_Diode.htm
:
:http://www.digitroncorp.com/parts/part_details.asp?/p
:
:art/1N3719
:
:http://www.4starelectronics.com/part_detail/1N3719.ht
:
:ml
:
:As for Digikey and Mouser, not sure if they carry the TD's.
:

:::Help!!
:::
:::I was wondering if anyone has a Tek 547 scope that is being used for parts?
:::
:::I am in need of the tunnel diodes used in the A & B trigger circuits. The General Electric P/N is TD 253. The Tektronix number is 152-154. Later serial numbers used the 152-0140-01, which is also a 10ma tunnel diode. This one may work as well.
:::
:::Alternately, does anyone know where I can buy these diodes? I have done, what I believe to be an extensive internet search to no avail.
:::
:::I am troubleshooting a problem with the A Timebase trigger. If anyone is interested in how I came to suspect the tunnel diode let me know. Maybe I am wrong and the problem is elsewhere.
:::
:::Any and all help would be greatly appreciated.
:::This is a great scope and it deserves to live!
:::
:::Gary
:::
::
::Hi Gary,
:: Did a lot of work on Tek scopes years ago. The TD was used in many models and the only one that was fussy was the 585. TD's were rarely the problem but we usually used 1N3719 as replacements in all the 500 series scopes. There is a whole family of TD's starting at 1N3714 that would be acceptable but check the specs against what you have. Here is some data and some current web sites to help you out.
::
::Bob
::
::General Electric P/N is TD 253 Tektronix number is
::
::152-154, use 152-0140-01 or 1N3719
::
::TD253A
::General Purpose Tunnel Diode
::General Electric Solid State
::Diodes
::V(f)(V) Forward Voltage @Ipeak=570m
::Ipeak Max. (A)=10m
::Peak Current Tol. (A)=1.0m
::V(P) (V) Peak-Point Voltage=80m
::V(V) (V) Valley-Point Voltage=410m
::Ratio Ipeak/Ivalley Min.=8.0
::I(F) Max. (A) Forward Current=10m
::r(s) Max. (Ohms) Series Res.=2.0
::L(s) Max.(H),Series Inductance=1.5n
::C(t) Max.(F) Total Capacitance=5.0p
::P(D) Max.(W) Power Dissipation=7.0m
::Semiconductor Material=Germanium
::Status=Discontinued
::
::
::http://www.americanmicrosemi.com/information/tutorial
::
::/index.php?t_id=11
::
::http://www.mpulsemw.com/Tunnel_Diode.htm
::
::http://www.digitroncorp.com/parts/part_details.asp?/p
::
::art/1N3719
::
::http://www.4starelectronics.com/part_detail/1N3719.ht
::
::ml
::
::As for Digikey and Mouser, not sure if they carry the TD's.
::
:
:Hi Bob,
:
:Thanks for the information.
:
:I have a 585 that I use for parts (I just remembered I had it last Friday!).
:
:The TD in this scope is similar to the TD253 in that it is also a (10 ma diode) so I installed it in the A Trigger circuit of my 547. I performed a calibration of the A Trigger and the trigger pulse amplitude is now per the calibration procedure and A Timebase triggers perfectly.
:
:I do plan on installing the correct TD but for now at least I am sure the triggering problem was due to a failed TD.
:
:Now I am back to the original problem with this scope, prior to the TD failure. The trace on the A Timebase has a bit of a jitter that is visible starting from around 60% of the trace width. The jitter progressively gets worse towards the end of the trace. The trace end appears to be stable but the vertical signal jitters horizontally. (Could this be trigger related?). Also, the A Timebase cannot be calibrated in that the adjustment of the A SWP CAL R290Y in Step 45 is at one end of its adjustment and the timebase is still off. I did an experiment and installed a resistor in series with R290Y and was able to adjust the A Timebase.
:
:Do you have any thoughts?
:
:Gary
:
:
:
As an ending note, most of the 500 series scopes used pairs of TD's in then so if you use 1N3719 do so in pairs for both the A and B trigger circuits. Glade to see you picked up on the 10 ma rating, I forgot to [ut that in my previous post. Let us know how you make out.

Bob