Hello All,
With the load removed and the resistor replaced I cannot get the relay to energize again. What's going on? Does there have to be a plug-in in the scope for the relay to energize? If no I can work with the scope until I get some tubes for another plug-in that I have.
The relay was energizing but after the load returned, it absolutely refuses to energize. Is the delay relay damaged or should I check something else?

Thanks,

Dave

Hello Again All,
I guess that the relay is out of adjustment because I measure 94 ohms between pins 6 and 9 of the delay relay when the scope is off. Those relay contacts have to make a better connection to get the delay relay to heat and turn on and disconnect the delay it's filament and connect the coil in the relay. I believe that that's how it works.

Thanks,

Dave
:Hello All,
: With the load removed and the resistor replaced I cannot get the relay to energize again. What's going on? Does there have to be a plug-in in the scope for the relay to energize? If no I can work with the scope until I get some tubes for another plug-in that I have.
: The relay was energizing but after the load returned, it absolutely refuses to energize. Is the delay relay damaged or should I check something else?
:
:
:Thanks,
:
:Dave
:

Hello Again,
I see now that if the relay contacts are good (clean and making good contact), after 20 seconds, the delay relay will energize, causing the main relay to energize and stay energized until the scope is turned off, no matter what the condition of the power supply is. I have removed the back and fan, and can now clean (file) the contacts of the relay. One is of the SPST contacts is rusty. There is a black contact (one of the spdt's) that probably also needs to be cleaned. I'll lightly file all of them until they make better contact. Also the relay seems to be sluggish on return, like something is binding. But I don't see what it could be. Are those two pivots on top the only pivot points? Where is the spring hidden? Is it just the contacts acting as a spring to pull it back when it's de-energized?
Once I have that delay relay circuit working, I should see high voltage even if there's no plug-in module in the scope at all.

Thanks,

Dave
:Hello Again All,
: I guess that the relay is out of adjustment because I measure 94 ohms between pins 6 and 9 of the delay relay when the scope is off. Those relay contacts have to make a better connection to get the delay relay to heat and turn on and disconnect the delay it's filament and connect the coil in the relay. I believe that that's how it works.
:
:Thanks,
:
:Dave
::Hello All,
:: With the load removed and the resistor replaced I cannot get the relay to energize again. What's going on? Does there have to be a plug-in in the scope for the relay to energize? If no I can work with the scope until I get some tubes for another plug-in that I have.
:: The relay was energizing but after the load returned, it absolutely refuses to energize. Is the delay relay damaged or should I check something else?
::
::
::Thanks,
::
::Dave
::
:

Edd,
Am I correct in saying that the operation of the delay-relay and regular relay are only dependent on two filament windings and a set of relay contacts? Whether the power supply works or not. If the two filament windings work and the relay's are working correctly, after 20 seconds, the regular relay will energize even if the power supply or other windings are not working. It is supposed to work that way. The only reason mine is not working correctly is because those normally closed relay contacts aren't clean. So the delay relay cannot heat properly and energize it's contacts. I just want to make sure I am correct. Am I?

Thanks,

Dave
:
:
:

: : : : : : :Sir David. . . . : : : : : :On again . . .off again ehhhh ? : : :The +100 supply does come in on pin 10 of the CA rear connector and the only low R value is that initial 27 ohms :which the supply has to initially pass thru. Then a like numbered bypass condenser past it to ground. : : :Then the circuit is isolated via higher value resistors in line, if not going to a tube element. : : :So anything ocurring past that 27 value would have to include it within the mix. : : :The other consideration would be the connector proper or something ocurring prior to it initially reaching that 27 ohm resistor. : : :Enclosed is a schematic of the CA unit with all +100 terminal supply points designated. : : :Plus you might additionally consult the verbiage of the prior post again. : : : : :Add on: : : : :But I now see that you are referring to the time delay relay, it is a thermal heater-bi metallic strip type of unit which gives time for the sets filaments to warm up before switching in most of the main B+ supplies of the set. : : :That is done when the larger multi section power relay activates by the eventual snap on action of that time delay relays :contact in the activation of the coil of the multi function relay. : : :DEFINITELY prefer a double folded strip of wet #800 silicon carbide (or make it ~ #1200 if you abrade it with itself multiple times) to then be pulled thru pressed together relay contacts to clean them. : : : :73's de Edd : : : :

:
:
:

: : : :Mark-Up . . . . Working. . . . .Tektronix CA Preamp- Plug In Schematic : : : : : : : : : : :

:
:
:
:
::Hello Again,
:: I see now that if the relay contacts are good (clean and making good contact), after 20 seconds, the delay relay will energize, causing the main relay to energize and stay energized until the scope is turned off, no matter what the condition of the power supply is. I have removed the back and fan, and can now clean (file) the contacts of the relay. One is of the SPST contacts is rusty. There is a black contact (one of the spdt's) that probably also needs to be cleaned. I'll lightly file all of them until they make better contact. Also the relay seems to be sluggish on return, like something is binding. But I don't see what it could be. Are those two pivots on top the only pivot points? Where is the spring hidden? Is it just the contacts acting as a spring to pull it back when it's de-energized?
:: Once I have that delay relay circuit working, I should see high voltage even if there's no plug-in module in the scope at all.
::
::Thanks,
::
::Dave
:::Hello Again All,
::: I guess that the relay is out of adjustment because I measure 94 ohms between pins 6 and 9 of the delay relay when the scope is off. Those relay contacts have to make a better connection to get the delay relay to heat and turn on and disconnect the delay it's filament and connect the coil in the relay. I believe that that's how it works.
:::
:::Thanks,
:::
:::Dave
::::Hello All,
:::: With the load removed and the resistor replaced I cannot get the relay to energize again. What's going on? Does there have to be a plug-in in the scope for the relay to energize? If no I can work with the scope until I get some tubes for another plug-in that I have.
:::: The relay was energizing but after the load returned, it absolutely refuses to energize. Is the delay relay damaged or should I check something else?
::::
::::
::::Thanks,
::::
::::Dave
::::
:::
::
:

Edd,
What's driving me crazy is that when the plug-in is disconnected from the scope there is no load. There is no load in the plug-in or the scope. Once they are mated the load returns. This is what's extremely frustrating. I cannot find something that's not there. Apparently that last time the load returned one of the 6980s cracked, it must have become so hot it cracked. I think that's what happened. I have a few spares. Or maybe it had very tiny hairline cracks in it that it obtained in shipping the scope. At first the cracks didn't allow air to get in. But now the tube got foggy looking and I can feel the cracks. But the glass didn't fall apart. I'm not sure when it happened but one minute the tube was working, the next minute I found it cracked.

Thanks,

Dave
:
:
:

: : : : : : :Sir David. . . . : : : : : :On again . . .off again ehhhh ? : : :The +100 supply does come in on pin 10 of the CA rear connector and the only low R value is that initial 27 ohms :which the supply has to initially pass thru. Then a like numbered bypass condenser past it to ground. : : :Then the circuit is isolated via higher value resistors in line, if not going to a tube element. : : :So anything ocurring past that 27 value would have to include it within the mix. : : :The other consideration would be the connector proper or something ocurring prior to it initially reaching that 27 ohm resistor. : : :Enclosed is a schematic of the CA unit with all +100 terminal supply points designated. : : :Plus you might additionally consult the verbiage of the prior post again. : : : : :Add on: : : : :But I now see that you are referring to the time delay relay, it is a thermal heater-bi metallic strip type of unit which gives time for the sets filaments to warm up before switching in most of the main B+ supplies of the set. : : :That is done when the larger multi section power relay activates by the eventual snap on action of that time delay relays :contact in the activation of the coil of the multi function relay. : : :DEFINITELY prefer a double folded strip of wet #800 silicon carbide (or make it ~ #1200 if you abrade it with itself multiple times) to then be pulled thru pressed together relay contacts to clean them. : : : :73's de Edd : : : :

:
:
:

: : : :Mark-Up . . . . Working. . . . .Tektronix CA Preamp- Plug In Schematic : : : : : : : : : : :

:
:
:
:
::Hello Again,
:: I see now that if the relay contacts are good (clean and making good contact), after 20 seconds, the delay relay will energize, causing the main relay to energize and stay energized until the scope is turned off, no matter what the condition of the power supply is. I have removed the back and fan, and can now clean (file) the contacts of the relay. One is of the SPST contacts is rusty. There is a black contact (one of the spdt's) that probably also needs to be cleaned. I'll lightly file all of them until they make better contact. Also the relay seems to be sluggish on return, like something is binding. But I don't see what it could be. Are those two pivots on top the only pivot points? Where is the spring hidden? Is it just the contacts acting as a spring to pull it back when it's de-energized?
:: Once I have that delay relay circuit working, I should see high voltage even if there's no plug-in module in the scope at all.
::
::Thanks,
::
::Dave
:::Hello Again All,
::: I guess that the relay is out of adjustment because I measure 94 ohms between pins 6 and 9 of the delay relay when the scope is off. Those relay contacts have to make a better connection to get the delay relay to heat and turn on and disconnect the delay it's filament and connect the coil in the relay. I believe that that's how it works.
:::
:::Thanks,
:::
:::Dave
::::Hello All,
:::: With the load removed and the resistor replaced I cannot get the relay to energize again. What's going on? Does there have to be a plug-in in the scope for the relay to energize? If no I can work with the scope until I get some tubes for another plug-in that I have.
:::: The relay was energizing but after the load returned, it absolutely refuses to energize. Is the delay relay damaged or should I check something else?
::::
::::
::::Thanks,
::::
::::Dave
::::
:::
::
:

Edd,
I'll get the carbide sand paper tomorrow.

Thanks,

Dave
:
:
:

: : : : : : :Sir David. . . . : : : : : :On again . . .off again ehhhh ? : : :The +100 supply does come in on pin 10 of the CA rear connector and the only low R value is that initial 27 ohms :which the supply has to initially pass thru. Then a like numbered bypass condenser past it to ground. : : :Then the circuit is isolated via higher value resistors in line, if not going to a tube element. : : :So anything ocurring past that 27 value would have to include it within the mix. : : :The other consideration would be the connector proper or something ocurring prior to it initially reaching that 27 ohm resistor. : : :Enclosed is a schematic of the CA unit with all +100 terminal supply points designated. : : :Plus you might additionally consult the verbiage of the prior post again. : : : : :Add on: : : : :But I now see that you are referring to the time delay relay, it is a thermal heater-bi metallic strip type of unit which gives time for the sets filaments to warm up before switching in most of the main B+ supplies of the set. : : :That is done when the larger multi section power relay activates by the eventual snap on action of that time delay relays :contact in the activation of the coil of the multi function relay. : : :DEFINITELY prefer a double folded strip of wet #800 silicon carbide (or make it ~ #1200 if you abrade it with itself multiple times) to then be pulled thru pressed together relay contacts to clean them. : : : :73's de Edd : : : :

:
:
:

: : : :Mark-Up . . . . Working. . . . .Tektronix CA Preamp- Plug In Schematic : : : : : : : : : : :

:
:
:
:
::Hello Again,
:: I see now that if the relay contacts are good (clean and making good contact), after 20 seconds, the delay relay will energize, causing the main relay to energize and stay energized until the scope is turned off, no matter what the condition of the power supply is. I have removed the back and fan, and can now clean (file) the contacts of the relay. One is of the SPST contacts is rusty. There is a black contact (one of the spdt's) that probably also needs to be cleaned. I'll lightly file all of them until they make better contact. Also the relay seems to be sluggish on return, like something is binding. But I don't see what it could be. Are those two pivots on top the only pivot points? Where is the spring hidden? Is it just the contacts acting as a spring to pull it back when it's de-energized?
:: Once I have that delay relay circuit working, I should see high voltage even if there's no plug-in module in the scope at all.
::
::Thanks,
::
::Dave
:::Hello Again All,
::: I guess that the relay is out of adjustment because I measure 94 ohms between pins 6 and 9 of the delay relay when the scope is off. Those relay contacts have to make a better connection to get the delay relay to heat and turn on and disconnect the delay it's filament and connect the coil in the relay. I believe that that's how it works.
:::
:::Thanks,
:::
:::Dave
::::Hello All,
:::: With the load removed and the resistor replaced I cannot get the relay to energize again. What's going on? Does there have to be a plug-in in the scope for the relay to energize? If no I can work with the scope until I get some tubes for another plug-in that I have.
:::: The relay was energizing but after the load returned, it absolutely refuses to energize. Is the delay relay damaged or should I check something else?
::::
::::
::::Thanks,
::::
::::Dave
::::
:::
::
:

Edd,
It looks like this sand paper has to be mail ordered. Nobody in this area seems to have higher than 600 grit, which makes no sense. When I search home center's websites for sand paper, it doesn't exist. This makes no sense either because they do sell sand paper, even the wet kind. But 600 is the highest grit (finest) they have. I'll find it at a hobby store.

Dave
:
:
:

: : : : : : :Sir David. . . . : : : : : :On again . . .off again ehhhh ? : : :The +100 supply does come in on pin 10 of the CA rear connector and the only low R value is that initial 27 ohms :which the supply has to initially pass thru. Then a like numbered bypass condenser past it to ground. : : :Then the circuit is isolated via higher value resistors in line, if not going to a tube element. : : :So anything ocurring past that 27 value would have to include it within the mix. : : :The other consideration would be the connector proper or something ocurring prior to it initially reaching that 27 ohm resistor. : : :Enclosed is a schematic of the CA unit with all +100 terminal supply points designated. : : :Plus you might additionally consult the verbiage of the prior post again. : : : : :Add on: : : : :But I now see that you are referring to the time delay relay, it is a thermal heater-bi metallic strip type of unit which gives time for the sets filaments to warm up before switching in most of the main B+ supplies of the set. : : :That is done when the larger multi section power relay activates by the eventual snap on action of that time delay relays :contact in the activation of the coil of the multi function relay. : : :DEFINITELY prefer a double folded strip of wet #800 silicon carbide (or make it ~ #1200 if you abrade it with itself multiple times) to then be pulled thru pressed together relay contacts to clean them. : : : :73's de Edd : : : :

:
:
:

: : : :Mark-Up . . . . Working. . . . .Tektronix CA Preamp- Plug In Schematic : : : : : : : : : : :

:
:
:
:
::Hello Again,
:: I see now that if the relay contacts are good (clean and making good contact), after 20 seconds, the delay relay will energize, causing the main relay to energize and stay energized until the scope is turned off, no matter what the condition of the power supply is. I have removed the back and fan, and can now clean (file) the contacts of the relay. One is of the SPST contacts is rusty. There is a black contact (one of the spdt's) that probably also needs to be cleaned. I'll lightly file all of them until they make better contact. Also the relay seems to be sluggish on return, like something is binding. But I don't see what it could be. Are those two pivots on top the only pivot points? Where is the spring hidden? Is it just the contacts acting as a spring to pull it back when it's de-energized?
:: Once I have that delay relay circuit working, I should see high voltage even if there's no plug-in module in the scope at all.
::
::Thanks,
::
::Dave
:::Hello Again All,
::: I guess that the relay is out of adjustment because I measure 94 ohms between pins 6 and 9 of the delay relay when the scope is off. Those relay contacts have to make a better connection to get the delay relay to heat and turn on and disconnect the delay it's filament and connect the coil in the relay. I believe that that's how it works.
:::
:::Thanks,
:::
:::Dave
::::Hello All,
:::: With the load removed and the resistor replaced I cannot get the relay to energize again. What's going on? Does there have to be a plug-in in the scope for the relay to energize? If no I can work with the scope until I get some tubes for another plug-in that I have.
:::: The relay was energizing but after the load returned, it absolutely refuses to energize. Is the delay relay damaged or should I check something else?
::::
::::
::::Thanks,
::::
::::Dave
::::
:::
::
:

Edd,
I found 1000 grit paper and cleaned the relay and the main relay does indeed come on after about 20 seconds again. There is no module plugged in but HV comes on and there's a tiny bit of arcing left somewhere. It doesn't snap all that often but it does snap occasionally. I cannot move the beam to the right. It's stuck off the screen to the left. What could be wrong if I cannot move it far enough using the horizontal centering control? I'll put this in another thread. Also, I will be getting the tube so I can use the D plug-in unit to avoid the heavy load (probably the topic for another thread as well).

Thanks,

Dave
:
:

: : : : : : : :Sir David. . . : : : : : : : : : :As for the multiple places stocking the wet’ n dry silicon carbide paper, even thru the auto-mo-bubble refinishing ree- sources, hobby shops etc. , I was surprised that you could not find that grit, however, that is why I ALSO mentioned the working of it against itself with another sheet to knock down the aggressiveness of the full grit rating, quite a bit. : : :Of course there is also the possibility of the use of a diamond dust nail file with its :ultra fine degree of abrasiveness, but I also frequently flush the surface with solvent and the additional use of a stiff, fine bristle hog hair brush, to clear its surface, since silver clogs it quite easily. BUT it does just need a touch for the cleaning of the contact faces. : : : : :As per your relay combination, note that the critical leaf contact assembly associated with even initiating the initial delay action is the series routing of the thermal winding thru the main relay’s contact section K 701-1 poprtion. : : :All is straight forward after the heat up, as the unit then self latches in and completes the series adding of the power supply sections. : : : : : : : :73's de Edd : : : :

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