Rick Stout's Pioneer Spec 4

[laatsch55]

Won't release relay to output jacks. Protection circuit is probably doing it's thing.

 

[laatsch55]

Ok, the schematic shows some STV-3H diodes. I'm familiar with those, even have a few. BUT, what is an SV-04, I know of STV-4H but not and SV-04.

 

[NavLinear]

Is this it?

View attachment SV-04 Datasheet.pdf

 

[laatsch55]

Yes sir, in the Spec 4 it's part of the drive voltage limiter circuit. Damn Nav, you rock. What'd it take, 2 minutes on the net? Really wasn't being lazy, just busy.

 

[NavLinear]

Cool! The search took me to a site that I visit often.

Some copied test:

A varistor is an electronic component with a "diode-like" nonlinear current–voltage characteristic. Varistors are often used to protect circuits against excessive transient voltages by incorporating them into the circuit in such a way that, when triggered, they will shunt the current created by the high voltage away from sensitive components. A varistor is also known as Voltage Dependent Resistor or VDR. A varistor’s function is to conduct significantly increased current when voltage is excessive.

 

[Gepetto]

You are familiar with them on your 3 phase detector boxes Lee.

 

[laatsch55]

I AM???

 

[laatsch55]

So they're triggered by a higher voltage so they can shunt excess current that is coming right behind the increased voltage??

 

[Gepetto]

So they're triggered by a higher voltage so they can shunt excess current that is coming right behind the increased voltage??

Yes you are Lee, they are the transorbs that are used to protect the circuit from lightning strike and crap that comes down the AC line like that. You may know them as Transorb or MOV.

 

[laatsch55]

Well, now that you are calling them MOV's , yeah, well acquainted. I have installed 20 of those phase relays now, and with lightning season just a couple weeks away we're about to see if all that work on your part is going to make them any more survivable. My money is on you!!

 

[Gepetto]

Well, now that you are calling them MOV's , yeah, well acquainted. I have installed 20 of those phase relays now, and with lightning season just a couple weeks away we're about to see if all that work on your part is going to make them any more survivable. My money is on you!!

You must be getting good at building them by now Lee.

 

[laatsch55]

I was pretty good at fixin em before you re-engineered that whole mess now. straight forward stuff. Breaking the two boys out on em. Honing their soldering skills.

 

[Gepetto]

I was pretty good at fixin em before you re-engineered that whole mess now. straight forward stuff. Breaking the two boys out on em. Honing their soldering skills.

Gotta be training the next generation Lee.

 

[laatsch55]

Absolutely Joe.

 

[laatsch55]

I have taken Chris' amp boards out in preparation of replacing all electrolytic caps, all transistors , trimpots and a diode or two.


So, I took the amp boards out of Rick's and put them into Chris'. Everthing went fine, both amp board relays pulled in and bias and offset were adjusted easily. What does that mean?? A lot less time and trouble seeing if anything is wrong with the amp boards. Now we know it's isolated to the meter amp board or power supply. It's real nice having 2 Spec 4's hetre with DIFFERENT things wrong with em.

 

[orange]

That the 'Jack Sprat' test, Lee?

 

[Elite-ist]

The ol' swap-'n-stop technique. You are right, that will help isolate the problem sooner, Lee. I am surprised at how much fuel you have got left in the tank at the end of a full work day to be tinkering on gear. I am just bagged after work, and just want to hear some tunes... with a beverage, of course.

Nando.

 

[laatsch55]

Nando , it has to be from those 16-18 hour days for the last 38 years. Also, check with any old speedfreak that shot dope for 30 years. Sleep does not come easily

 

[laatsch55]

That the 'Jack Sprat' test, Lee?

Very similiar Steve, very similiar

 

[laatsch55]

Right amp board done....