Search found 75 matches

by Wolfgang Felber
Wed Oct 30, 2019 3:37 am
Forum: General Vinyl
Topic: Technics SP10 mk2 - no electronic brake...
Replies: 16
Views: 8467

Re: Technics SP10 mk2 - no electronic brake...

Hi Nick, once possibly twice per side.
by Wolfgang Felber
Tue Oct 29, 2019 11:43 pm
Forum: General Vinyl
Topic: Technics SP10 mk2 - no electronic brake...
Replies: 16
Views: 8467

Re: Technics SP10 mk2 - no electronic brake...

Hi Nick, interesting, reading the last post, I have set up the non working, now working SP10 with an arm and cartridge. I have been listening and enjoying but every so often, the platter slows down, not slowly but quickly and then returns to normal speed. It is as if there was a brake put on it. I c...
by Wolfgang Felber
Thu Oct 03, 2019 12:43 pm
Forum: General Vinyl
Topic: Technics Sp10 Woes
Replies: 122
Views: 60833

Re: Technics Sp10 Woes

Hi Nick, Thankyou for that, I did see something on another site, it is made up of 3 x LED,s 1 x 2n2222, and a couple of resistors. Unfortunately, I am not sure where to connect it to to get the correct flashing rate to give you a good steady square. I tried the neons and they just dont get bright en...
by Wolfgang Felber
Fri Aug 30, 2019 12:23 pm
Forum: General Vinyl
Topic: Technics Sp10 Woes
Replies: 122
Views: 60833

Re: Technics Sp10 Woes

Hi Nick, any chance that you have a photo of how to connect the LED to the logic. Will the LED flash at the correct frequency, so that the squares on the platter don't move.

Regards

Wolfgang
by Wolfgang Felber
Thu Aug 29, 2019 12:36 pm
Forum: General Vinyl
Topic: Technics Sp10 Woes
Replies: 122
Views: 60833

Re: Technics Sp10 Woes

Hi Nick , been off line for a while, making up two plinths for the SP10's. I have a question, I noticed that the neon flickers. Any ideas what is casing that. When I first started with the, getting it up and running, I noticed the two transistors that drive the neon used to get really hot. Do you th...
by Wolfgang Felber
Mon Aug 05, 2019 11:19 pm
Forum: General Vinyl
Topic: Technics Sp10 Woes
Replies: 122
Views: 60833

Re: Technics Sp10 Woes

Hi Nick, I tested your explanation last night, if you put a little pressure on the platter to slow it down, you notice the impulse moves to the right and increases in intensity. Once the platter is back at the required speed the impulse moves back to its original position and the intensity drops bac...
by Wolfgang Felber
Mon Aug 05, 2019 1:18 am
Forum: General Vinyl
Topic: Technics Sp10 Woes
Replies: 122
Views: 60833

Re: Technics Sp10 Woes

Hi Nick, absolutely my question, if I have learnt anything from this two year exercise, is you are never too old to learn. believe it not, your explanation does make sense, I have done a bit of research on Sample & Hold circuits to find out what it is all about. My next project is to make a plin...
by Wolfgang Felber
Sun Aug 04, 2019 11:32 am
Forum: General Vinyl
Topic: Technics Sp10 Woes
Replies: 122
Views: 60833

Re: Technics Sp10 Woes

Hi Nick, now that I have got to this point, can you please explain the significance of the time base and the difference between the Sawtooth Wave form and the impulse wave form.
by Wolfgang Felber
Sun Aug 04, 2019 2:47 am
Forum: General Vinyl
Topic: Technics Sp10 Woes
Replies: 122
Views: 60833

Re: Technics Sp10 Woes

Hi Nick, finally worked out how to measure the timebase, I have attached some photos, hopefully they are ok.
by Wolfgang Felber
Sat Aug 03, 2019 12:00 pm
Forum: General Vinyl
Topic: Technics Sp10 Woes
Replies: 122
Views: 60833

Re: Technics Sp10 Woes

Just a couple of photos to show the wave forms, hopefully they are OK in your eyes.
by Wolfgang Felber
Sat Aug 03, 2019 11:45 am
Forum: General Vinyl
Topic: Technics Sp10 Woes
Replies: 122
Views: 60833

Re: Technics Sp10 Woes

Lots of smily faces, Nick, you wont believe it, I got it going with the right wave forms. The only thing that needed adjusting was 78rpm, 33 and 45 both locked on perfectly. What I did, was replace TR121, TR128, TR151, TR152, TR153 & TR154. the whole sample and hold setup. Mate, how do I ever th...
by Wolfgang Felber
Sat Jul 13, 2019 4:16 am
Forum: General Vinyl
Topic: Technics Sp10 Woes
Replies: 122
Views: 60833

Re: Technics Sp10 Woes

Hi Nick, replaced TR 151 with a 2SK30a, still getting identical waveforms. I was looking at the circuit diagram and test points S & T are adjacent to TR153 & TR154, could any of these be the culprit? I will test around them and see what happens.
by Wolfgang Felber
Fri Jul 12, 2019 11:19 am
Forum: General Vinyl
Topic: Technics Sp10 Woes
Replies: 122
Views: 60833

Re: Technics Sp10 Woes

Hi Nick, I can do that, I purchased a full set of replacement transistors, so if you ever need any.
by Wolfgang Felber
Fri Jul 12, 2019 1:19 am
Forum: General Vinyl
Topic: Technics Sp10 Woes
Replies: 122
Views: 60833

Re: Technics Sp10 Woes

Hi Nick, Tested the resistor between S & T, reading is 147.7K. Also tested the scope probes, just in case there was a short in them, they are both fine. so it looks like the TR 151 could be faulty. Will check it tonight. Testing JFets is a little different to std standard transistors, is that co...
by Wolfgang Felber
Wed Jul 10, 2019 11:20 pm
Forum: General Vinyl
Topic: Technics Sp10 Woes
Replies: 122
Views: 60833

Re: Technics Sp10 Woes

Hi Nick, just looked at the circuit diagram and found the R186 that is supposed to be a 150K resistor. will check it tonight. also the TR151, 152, 153 & 154, they are a JFET?