VL200 Stepper issue

[prime]

Hi guys I have a VL200 with a TSR-3-L6 receiver, the amp im using now is the Victory Glass solid state. Ive been having an issue ever since trying to use a wall box. The wall box had poor connections in the unit and had some work done on rewiring lighting. When trying it it may have caused issues. Ive got the wall box resolved and for now am just using the Juke Talk app to select songs, this rules out any possible issue with the wall unit. My issue is when i select a song only the letter clapper (letter stepper switches) move it does not transfer to number side, If i push the play control first so the carriage is moving, i can select as many songs as i wish and they all work perfectly. Letter then number clappers do their thing. Once the last song has played and the carriage goes back to rest, if i select a song only the letter clapper works and it pulses the letter, then number on the same side.  Any thoughts on this  The receiver was recapped about 2 years ago but the wall box may have damaged something.  

[jukenorman]

I have no idea! On the face of it, there is little connection betwwen the scan control and the stepper. The scan control from the stepper is initiated when the step sequence is complete, at the same time as the selection is written. The changeover from the letter stepper to the number stepper is a function of the transfer relay which is held by a timing circuit while the letter stepper is incrementing. To complicate matters slightly, the VG app must interface with some modification that they have carried out to enable their amp to connect to the stepper thryatron and about which I know nothing (ie the app must communicate with the VG amp and the amp must be able to drive the stepper thyratron).

As a bit of a guess, have you tried swopping the two thyratrons (stepper and trip 2050s) or a new thyratron to see if that makes a difference? Failing that, you may need to consult Victory Glass!


Norman.

[prime]

Hi Norman, I tried with just the wallbox not the app, same issue, I have swapped 2050 tubes in the receiver ,no change, unless both tubes are defective i should be ok. Using the electrical selector all is perfect. I have a question. i notice number three on the 2050 socket goes to stepper plate and has a 5 uf cap between line 15 and 14. I cannot find that cap, is it inside the silver box as per photo, and if it was defective could it affect the operation? pete

[jukenorman]

That is the capacitor! If the wallbox is good and it doesn't change from letters to numbers, it's normally down to the tranfer relay in the stepper and its timing circuit, capacitor C25 - did that get changed out?

Norman.

[prime]

Hi Norman i found the issue, I had noticed the switch circled in green seemed to stick ever so slightly when pushing it down, i oiled all moving parts and played with it and then it seemed to work well. I decided to rightly or wrongly use a very small flat file and file below the plate and the coil top. After which i tried again with out the carriage engauged and low and behold it works. I can only assume that switch has something to do with timing or affects it. pete

[jukenorman]

That's the transfer relay!

[jukenorman]

Just to add, it was probably the vibration of the motor that was "persuading" the transfer relay to operate normally when the mechanism was in play mode. I hope that doesn't mean that the motor needs oiling?

Norman.

[prime]

Hi Norman, interesting observation, Im pretty sure its oiled but will check.Just want to pick your brain on one more item. As i mentioned earlier, when i filed below the metal plate, all started working properly. The problem with the stepper all started when i connected a wall box, yesterday i was working on the wall box again , i have some of the selections select one letter prior but always the correct number. I made sure the wiper arm adjustment was as per manual thinking this may have caused this. I have previously cleaned the selector by removing the upper and lower plate, removing buttons and the plastic diffuser below it ,sprayed the selector with degreaser, let sit for 4 minutes ,spray with warm distilled water and repeat. I made sure water did not hit the transformer.I tried the wallbox a few times to see if i could get the proper selection, after about 6 selections the stepper stopped again ,so i filed a little more and all works perfectly again. Could this be an issue with wall box?, or is this just a fluke. Lastly is there anything else besides my filing you feel should be done. pete

[jukenorman]

I have no idea why the filing has solved your problem so it could be a fluke! Have you been over the contacts on the transfer relay? The thyratron pretty much isolates the wallbox from the stepper so it's unlikely that the wallbox is causing an issue with the stepper operation, so long as the thyratron is working. If you're losing a letter pulse, that could be down to either the wallbox or the stepper. But if you can drive the stepper successfully with the VG app., then that proves the stepper. You should be able to see and count the pulses on the glow of the thyratron, letter pulses - gap - number pulses.

Norman.

[prime]

Hi Norman i read your reply and now have recleaned the contacts on the transfer relay with D-oxit 5 and paper card, then a light burnish, also made sure gaps were close to spec. This will be my last question on this subject, when using the app all is perfect, when using the S3WA wall box i get two pulses on the number side, so i play two songs, wiper arm is set as per manual, rivets and switches have been cleaned. Cant adjust wiper arm pressure because its in ounces, i have nothing that measures that only a gram tool.When i use my multimeter and connect one end to blue wire and the other end touching rivets ,when i select any number or letter i get continuity on all rivets leading up to selection, so its working perfectly.. Does this confirm it must be an issue with contacts in the selector?

[jukenorman]

The problem with using your multimeter (particularly a digital one) is that only miniscule current is required and the wiper and contact are stationary when you are doing the reading. You would get a better indication using a test lamp which passes much more current - that is what I do when I test items like that (I started doing this for AMI pulse converter testing and found it very telling). Ron would have said the same about your multimeter and you might recall he did, many times!

Norman.

[prime]

Hi Norman ,i do remember Rons teaching so i used both analog and multimeter. Ron had directed me to make a tester using a battery and a bulb from a flashlight, i used it to test the wiper wheel. i pushed the N letter selector and connected the negative side of the battery tester to the blue wire, i then used the bulb connected to the positive side,and touched the back of the bulb to  rivets, starting from the V rivet i didn't get the light bulb lit on the first 7 rivets, every other letter rivet light up. The 8th rivet would be the letter N. This should confirm the selector is working, should it not?  It just drives me nuts that with the app it works perfectly but with the wall box it always sends two pulses to the number clapper. 

[jukeboxmarty]

Feb 1, 2024 22:35:54 GMT prime said:

...it always sends two pulses to the number clapper. 

Can you clarify that?

The number step relay is the second one to actuate in the sequence. Are you saying that when it fails, the selection sequence bypasses the letter step relay?

[prime]

Ill try to be very clear, when using the app and selecting C3 I get 4 pulses on the letter clapper, then 3 pulses on the number clapper and carriage selects C3, using the wall box selecting C3 I get 4 pulses on the letter clapper ,then 2 pulses on the number clapper then a split second later 6 pulses on the number clapper and carriage selects C2 then after playing or rejecting C6

[jukeboxmarty]

Maybe the wallbox is sending out more pulses than it should.

I don't see how the steppers can react 12 times when the wallbox should only put out 7 pulses (for selection C3).