Vinyl Old timers: HK's and Rabco's


Need some help here. I have seen several old HK ( Harman Kardon ) TT's that had Rabco linear trackers on them. I always assumed that this was the Rabco 8 arm. I recently saw a Rabco 8 for sale on a website and it was completely different. The arms that i remembered looked like a regular linear tracking arm with a straight tube and a headshell. The 8 as displayed on this website looked like a much wider and flatter piece of metal i.e. almost like a piece of flat-stock.

If this really is a Rabco 8, what model arm is it that i recall as being stock on the old HK tables ? Sean
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sean
THANK YOU for all of your help. I appreciate the quick responses and tips / tricks / links for further info.

As to Steve's description of how the tubular arm is driven, i'm sure that you did a bang-up job of describing it. However, i'm having a hard time understanding exactly what you mean. I'm sure that it would all fall into place once i could see a diagram or actual unit that was "gutted".

I will check the thread on AA and see if it answers my questions. Just in case though, i was curious as to whether or not the tubular Rabco arm could "easily" be installed onto another TT ??? Judging by Steve's description, it doesn't really sound like it. Sean
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Sean,

There is a better description of the mechanism in Jason Gold's review of the ST-7 at Audio Review (of all places!):

http://www.audioreview.com/TurnTables/Harman,Kardon,RABCO,ST-7/PRD_121324_1597crx.aspx

Because the rotating tracking arm is coupled to the rotation at the platter spindle, I don't think the HK versions of the Rabco arm can be fitted readily to other turntables.

I thought the HK was a pretty good-sounding turntable, but I don't know how it would compare to today's "meat and potatoes", like Regas.
1. It would be very difficult, but not impossible, for an adept person to remove an arm from an ST-5,7 or 8 to install on another turntable since, on these, the main turntable motor drives the rotating armtube via an additional pulley on the main shaft of the platter.

2. The rubber drive wheel that engages the rotating arm tube can deteriorate or wear but it is replaceable by an "O"-ring used for plumbing. A ring with 3/8" i.d. and 19/32" o.d. is available and a perfect fit. I get them from Home Depot at 5 for 79cents.
Hasn't been that long ago (13 years ago) I had a Shreve modified Rabco SL8-E.....I had an SL-8 for a while until David built the one with the electric cuing for me....Had them on a Goldmund Studio Mk IV and it was an awesome combination as both ate the ET-2 I used before that on the same table.....Balsa wood arms with class nine bearings were pretty special.....Just a mess to keep working and even the brand of battery made a difference in the sound with the Kodak being the best....Sold the outfit to a friend and he is still using that combo today.....
Jeez Crump your as bad as me with the mod thing! Why don't you build a preamp and name it BlowTorch or something?