Author Topic: Trying to verify all pickups are doing there job.1973 Stage FR '73  (Read 206 times)

Offline JB

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Hi Wizards, Fans, Players, Sean, Rhodesmasters, Stevio and forgive me if I'm leaving someone else out,
Though I have done the "tap the magnets test" 3 times with the amp on and gotten consistent good results thru all 73 pickups and aligned all tines and pickups correctly but still can't get much if anything out of the last 11 high treble keys I'm suspecting hammers aren't hitting the tines but can't actually see it even when I look directly at them while striking such short tines. It's not like longer ones you can see vibrating as you strike them. Or maybe it's my eyesight and departed high end and cobwebs. I hope someone has a recommendation, I'm all partial ears. So, my question is: If I pivot the harp up vertical after removing the screws, with the amp on and strike the tines lightly with say, a small screw driver and it makes good noise, wouldn't that indicate the pickups are good and the hammers aren't hitting them? Note, I did the above and get no sound from keys 61 thru 73 after tappinng the tines with the harp top vertical. All the magnets on the pick ups sound exactly the same when tapped and plugged in to an amp so is the tapping the magnets not a fool proof way to ascertain pickup performance?

Just want to say what a great website this is with a great attitude and terrific players to be part of..thank you all.  JB
« Last Edit: July 27, 2020, 08:45:47 AM by JB »

Offline sean

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Re: Trying to verify all pickups are doing their job.1973 Stage FR '73
« Reply #1 on: July 27, 2020, 06:34:23 PM »

JB,

When you tap a screwdriver against those pickups, you hear a loud POP through the amp, correct?  (that means the coil is intact)
Can you feel the pull of the magnet on these pickups?  (To confirm that the magnet is still inside the pickup bobbin.)

If you just said "yes" twice, then...

If you can make the tines vibrate, but do not get any sound from the pickups, then the tine is NOT close enough to the pickup.  It may be too far back, it may be too far above, or it may be too far below.  (Remember, a short tine without a tuning spring will make almost no sound or sustain at all, so test on a tine that has a tuning spring installed.)
__________

You can easily test the swing of the hammers and see exactly where they contact the tines: 
1.  Remove the screws at each end of the name rail, unplug the grey cable that goes to the back left corner of the harp, and set the name rail aside.
2.  Reach your hand in from the front, and lift the hammers manually with your fingers.

Then you will see where the hammer is going to hit the tine, or where it bangs against the tine block, or the end of the damper arm.

Sean
« Last Edit: July 27, 2020, 06:37:51 PM by sean »

Offline JB

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Re: Trying to verify all pickups are doing there job.1973 Stage FR '73
« Reply #2 on: July 28, 2020, 08:52:42 AM »
Morning Sean,
    Thanks for your input. The tine tips are darn close to the pickups and I believe all are in front of the magnet not missing it above below or to the side. I adjusted the position 2 days ago using the new tine block as the 3/8 clearance for the front springs. I'll put found springs on the last 2 today. There is not a loud pop when I test them but all are just like tapping on a hot mic on stage and consistent. I do feel some magnetism but didn't now I was supposed to be concerned that all feel the same pull. Do you mean that the magnet of the pickup can come loose from the housing or bobbin as you put it? I will check that. My good friend BC who is a terrific guitar player and vintage repairman forever and knows amps and guitars thoroughly but can't look at it said he believes my pickups are probably good due to my multiple magnet tap testing results and that he has seen tons of amps and pickups that had lousy original or redone soldering or that the soldering itself has oxidized to a point to where it shorts out. He said good soldering is an art and not many people are very good at it..Just seems odd that all 10 or 11 keys aren't sounding off and they are lined up correctly at the magnets. The tines aren't rusted or loose on the tone rail and I tapped and sort of strummed all of them with a screw driver with amp connected with harp vertical yesterday and the last 10 or so made no or little sound compared to the notes before it. Do you suggest I get vohm and alligator clips and go that route or will that help if it's just a bad or corroded connection or soldering spot. Btw, I'll take the new low e tine to him and use his vise to tighten it to the tone bar and put one more spring on it and see if that works. Thanks Sean.