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  #1  
Old 09-23-2009, 09:01 AM
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Harmon Kardon Rabco ST-7

Hello all, First time here. I am purchasing an ST-7. It is a linear tracking turntable. It works but will be needing a new belt. Rollers are good (they say).

My use for this is to install a Quad Cartidge on it and use it for playing through a QRX 9001 and also recording 4 channel reel to reel.

What is your opinion of this turntable?

Thank you,,
George
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Old 09-23-2009, 11:21 AM
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Welcome to the forums!

The rabco arm was the role model for many mid fi linear and servo arm tables, also the uber tech goldmund arm was derived from it.

It needs to be maintaned but is an incredible design.

btw yes it sounds good
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Last edited by Marek; 09-23-2009 at 03:05 PM. Reason: spelling
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Old 09-23-2009, 12:26 PM
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Socal Sam Socal Sam is offline
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Good rollers are the key to the Rabco arm. Unfortunately, they are made out of cheap nylon or plastic and break with age. If the rollers break, the arm block will not advance on the track bar making your TT a beautiful door stop. Be very careful when replacing the belts. There are two, one for the arm and another for the platter.
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Old 09-23-2009, 02:34 PM
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I've got an ST7, ST8, ST4 etc. The ST7 is a fantastic sounding turntable when set up and working properly. The arm roller is a small o ring belt stretched around a roller. I got one that fit from a faucet washer assortment pack from Lowes. The ST8 has a slightly different system and better cueing using an pneumatic dash pot. However they are made of glass and can get broken easily. As has been said before there is a platter belt and an arm belt that runs from the platter to the arm rod pulley. They use a proprietary arm wand so if it is missing or broken they are hard to come by. I use one daily on my office system. The service manual is available for free download at vinylengine.com.

Dave
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Old 09-24-2009, 06:57 AM
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Hi Dave, I am unsure what you mean by "arm wand". Is that the main metal piece that holds the stylist that moves across the record?

By the way I just got it for $75.00. Will be shipping on the first of next month.
George
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Old 09-24-2009, 10:06 AM
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The ST7 instead of having a regular headshell the entire arm tube unplugs back near the pivot point. $75 is a great price if its in decent shape. They can get $150-200ish on Fleabay. One flaw they have is the cheap ass dust covers that always bust out at the hinges. Pretty much all of them have been glued back together multiple times or tossed out altogether.

Dave
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Old 09-24-2009, 06:10 PM
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Talking

Dave, Now I understand. Its the arm mechanism. the advert says.

This unit works but, the tone arm lifts up before the last song on the album is completed. I believe there is some type of adjustment for this, but I'm not aware what it is. The cosmetic condition is good. the dust cover has cracks around the hinge area. This is a belt drive turntable, the belt may need to be change soon. The stylus is good, sound output is clear, but stylus should be changed soon. The purchaser of this unit should be aware that it's going to need some minor work. but as it is now, it does play album.

George
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Old 09-24-2009, 06:45 PM
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i hope the guy knows how to pack a turntable for shipping. you might want to sacrifice a virgin for the shipping gods....
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Old 09-24-2009, 07:13 PM
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The belts are still available so thats not a problem. The sensor that trips the end of record lift is a metal flag thats adjustable that blocks light to a photocell. It will also trip early if the arm speed adjustment on the back of the arm is to fast causing the arm to be ahead of where it should be angle wise. The table also should be set up very level.

Dave
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Old 09-24-2009, 08:04 PM
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My ST-7 had a very nice dust cover that was relatively clear and only a little cracked at the back hinge. I wish it wasn't broken. It was a fine sounding table. It had a vintage Stanton cart, the one with the little track brush.
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  #11  
Old 09-25-2009, 06:41 AM
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That is a nice table.
I had one set up as my Quad table with an AT 15SA on it.
It is not a simple table to set up though.
Once its working it is great.
Good luck with yours.
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  #12  
Old 10-09-2009, 05:56 AM
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harmon st7 turntable

Well, I received the ST-7 today. It was packed really well but upon opening it up the dust cover was broken. I carefully unpacked it, put a record on it and plugged it in. The platter moved and then stopped. I removed the platter and found that the spindle shaft was bent causing the platter to wobble which caused the platter to scrape the base of the unit. This was causing the platter to stop.

I emailed pacific electronics (the seller) and explained the problem and how it could have not worked as they advertised. In the past with other sellers, when I approach them civilally they refund a portion of the price. I hope so in this case.

Everything else seems to work and all the parts are there. I cleaned it up and lubed the spindle shaft, arm rods and motor. Has anyone had sucsess in straightening a slightly bent spindle? I doubt that I could find a replacement part other than finding another ST-7.

George
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  #13  
Old 10-09-2009, 06:22 AM
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That really sucks man. You'll probably need to take the shaft to a machine shop to get it straightened or reproduced which won't be cheap. Or look for a parts unit for cheap. The dust covers are really flimsy and it should have been shipped off the table. The platter should have either been removed or had thick cardboard shims under it to prevent the shaft getting bent. I hope the seller will do the right thing.

Dave
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  #14  
Old 10-09-2009, 07:18 AM
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Socal Sam Socal Sam is offline
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That's terrible news. IME, TT are the worst items to pack and even the most careful packing jobs cannot prevent damage. The Fedex counter told me that at the hubs during the automated sort, packages travel down belts and then are literally shoved into destination bins. The drop is about four feet and EVERY package is subjected to this, TWICE.
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  #15  
Old 10-22-2009, 10:29 AM
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I found an alternator shop to straighten out the shaft. He told me he could get it withing 16 thousands of an inch. I should be hearing from him next week. He didn't seem to concerned that he couldn't make it right.

I have since sanded and steel wool'ed the aluminum metal throughout. It looks really nice. So, I'll post when I get the part back and hopefully some pics.

George
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  #16  
Old 11-10-2009, 07:19 AM
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turntable spindle bent

Well, I got the spindle assy back and tested it. It doesn't wobble as bad but is unuseable. Since the top portion of it is bent, I'm thinking of having that portion cut off and have a block of metal welded on and then run through a metal lathe the should true it up. Now I'm off to find a shop that will do that. If I knew someone who had one of those mini lathes the one that makes wooden pens, I would use that I think.
George
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  #17  
Old 12-20-2009, 07:04 AM
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Talking New ST-7

Hello. I found another ST-7 and received it. Very good condition with no cracks on the dust cover. Cleaned it up. It would not track the record. The tracking roller was gooie. Had a heck of a time getting that roller out. Cleaned it up but have to find a better way of dismantling that section to install that roller. I have the maintenance manual but it does not give instructions of how to replace the roller. Does anyone have any experience in that?
cheers.
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  #18  
Old 12-20-2009, 08:38 AM
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The last one I did I found it easier to unslober the arm wires and remove the entire carriage. Was still a royal pain. At least it will last another 20 years. Make sure the "gap" is even from one end to the other is the main thing when putting it back together.

Dave

Quote:
Originally Posted by Satcom123 View Post
Hello. I found another ST-7 and received it. Very good condition with no cracks on the dust cover. Cleaned it up. It would not track the record. The tracking roller was gooie. Had a heck of a time getting that roller out. Cleaned it up but have to find a better way of dismantling that section to install that roller. I have the maintenance manual but it does not give instructions of how to replace the roller. Does anyone have any experience in that?
cheers.
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