Wierd ohm reading?

Are you sure they need to be replaced? You can check them by connecting meter leads to various combinations of terminals, and turn the control from one end of its travel to the other. If you see resistance go smoothly up and down with at least two of those combinations then the control is probably fine.

I seem to remember this whole thread started when your replacement horn tweeters didn't seem to have the correct DC resistance. Have you actually hooked them up and played them? What's not working the way it should at this point? Regardless of meter readings.
 

I'm sorry, it's pretty much useless to try an explain this to me.
I understand it's function and how it basically works using resistance and all, what I don't get is that an L-Pad looks pretty much like an "L" in a schematic, at least that's what I read.
Mine does not look like an "L" in the schematic to me. I'll just desolder the buggers from the board when the time comes and see if I can get replacements, what ever the dadburn things are.
I swear I was NOT this dense 20 years ago. dash1.gif
 
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Are you sure they need to be replaced? You can check them by connecting meter leads to various combinations of terminals, and turn the control from one end of its travel to the other. If you see resistance go smoothly up and down with at least two of those combinations then the control is probably fine.

I seem to remember this whole thread started when your replacement horn tweeters didn't seem to have the correct DC resistance. Have you actually hooked them up and played them? What's not working the way it should at this point? Regardless of meter readings.

The controls never worked well and were sporadic at best. One day I fiddle with them and while doing so a tweeter went out again, one I repaired but, had little resistance.
Tried to clean them up with contact cleaner with no change. This is when I seen a bent wiper in one of the controls and decided to take it apart and repair it.
And then I posted asking the question , can a bad crossover damage a speaker? They crackle and cut out when turned and cleaning didn't help and, rebuilding the other made it worse (must have got something wrong when I reassembled it). So, this is why I think I need to replace them and while doing so recap it just to CMA. Hey, it's good therapy for me and it's not like I got anything else to do with my time being retired so to speak.
 
OK, that makes sense. Sounds like they do need to be replaced, although some controls can require more than one cleaning to get clean.
 
Once I get back into it again, 1st of the month probably I can post the exact ones I have, both sides showing the traces
but, for now here are some 701's that are identical to mine but, only showing one side.

Pair-of-Pioneer-Crossover-SNP-035-0-from-Pioneer-_1.jpg s-l1600.jpg
 
Ok, those are not lpads they are rotary switches with resistors. Get a can of Caig DeOxit D5, spray the switch contacts well, rotate 50 times and that will clear up any scratchiness. Would highly recommend changing the electrolytic capacitors if you are up for a little desoldering and soldering. Looks like 4 on each board. Piece of cake. If it were me, that is all I would do.
 
OK, that makes sense. Sounds like they do need to be replaced, although some controls can require more than one cleaning to get clean.

Oh, I cleaned the piss out of'em and it just didn't seem to get any better at all, besides the bent wiper wasn't helping matters either.
I want you to know I really appreciate you helping me with this cantankerous ole thing and looking past my dimness of mind ta boot, your a very patient man sir. yessir.gif
 
Ok, those are not lpads they are rotary switches with resistors. Get a can of Caig DeOxit D5, spray the switch contacts well, rotate 50 times and that will clear up any scratchiness. Would highly recommend changing the electrolytic capacitors if you are up for a little desoldering and soldering. Looks like 4 on each board. Piece of cake. If it were me, that is all I would do.

Not even going to try and clean them anymore then I have already sir, just going to rip'em out and put new ones in along with caps.
Soldering and desoldering is one of the few dadburn things I do remember how to do, I reckon cause my Mom worked at Electrostrings/ Rickenbacker and taught me when I was 14 how to.
 
Ok, someone on here may know where you could find suitable rotary switches but we will need some good pics and shaft length measurement (of the rotary switches) ;)
I guess we need to know if the end has splines or just a plain shaft meant for a knob with a set screw.
 
Ok, someone on here may know where you could find suitable rotary switches but we will need some good pics and shaft length measurement (of the rotary switches) ;)
I guess we need to know if the end has splines or just a plain shaft meant for a knob with a set screw.

Oh, they have splines for a push on knob maybe 1/2" to 5/8" long. I'll check that all out when I get back into it next month and desolder it all.
Thank you again!
 
Okay, without tearing into it today I thought I'd research where to pick up the rotary switches needed for the crossover.
Well, there seem to be everywhere but, my only problem is determining whether they are 3 position switches or 6, this is were my knowledge has lapsed.
They are indeed 2 pole because there are 2 inside contacts and they have 2 wipers one on each side of the switch. Now they have 3 positions (Increase, decrease and normal) but, they literally
have 6 if you were to count the other side that either opens or closes the contacts between the two sides depending what you have the selector at. Gees! I hope that made a little sense.
Look at the schematic of the selector and maybe that will explain what I mean. What would you say it is?
I know I could open it up and pull the selectors/rotary switches and find out that way, just don't want to tackle it today.

CS-701A.jpg
 
2 pole 3 way rotary switch. Remember, size, pin configuration, shaft length and splined or not all will need to be considered. Check Mouser and Digikey.
 
2 pole 3 way rotary switch. Remember, size, pin configuration, shaft length and splined or not all will need to be considered. Check Mouser and Digikey.

Yes and Thank you sir! Just trying to get an estimate cost is all, no ordering till I get them pulled and check them out well.
 
Another way to clean those switches is to get a business card (or equivalent), wet it with contact cleaner, and slide it back and forth between the contacts. That also avoids soaking the wafers which can retain the less volatile parts of cleaners. Deoxit D5 is 5% of an oily substance that can actually cause some conductivity and leakage. Although usually with higher voltages that what you would see in speakers.
 
BTW those black cylinders around the switches with multiple taps on them are the resistors shown in the schematic. Those look to be wirewound which is how they can put multiples in one package.
 
Another way to clean those switches is to get a business card (or equivalent), wet it with contact cleaner, and slide it back and forth between the contacts. That also avoids soaking the wafers which can retain the less volatile parts of cleaners. Deoxit D5 is 5% of an oily substance that can actually cause some conductivity and leakage. Although usually with higher voltages that what you would see in speakers.

Yes sir, usually if I can't get them clean enough by spraying them I use 400-1000 grit (depending ion how bad they are) folded over a business card or the like and that usually cleans the up toot sweet.

BTW those black cylinders around the switches with multiple taps on them are the resistors shown in the schematic. Those look to be wire wound which is how they can put multiples in one package.

And yep! That I knew.
 
Just purchased another Pioneer PT-411F Tweeter horn, 701A crossover and a Midrange horn in a package deal and, hopefully
there fully functional as the seller stated. If so I won't have to replace the bad rotary switch and fool with trying to restore the coil on the tweeter driver.
I'm sure I'll have to clean up the switches and maybe replace some caps but, it's a far easier job to do for me.
Now the wait to see if they get here in one piece. ChickenDance.gif

Oh! And I was just given a set of Kenwood 90W speakers, KL-555A's, not the best there is but,
will take the place of the Pioneer 701A's till I get them up to snuff. I had gave them to my son-in-law years ago and he hasn't a need for them anymore and gifted them back to me.
 
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