On 3/30/2011 7:20 PM, Tom Fine wrote:
> Rod, here's a PDF of the Ampex strobe stickers:
> http://recordist.com/ampex/schematics/300man/300strobe.pdf
>
> 60hz, I think 15IPS.

This looks like how Andy Worhol would have interpreted sunrays if he 
worked in black and white!


> Question for the group -- what if one scanned the strobe pattern on 
> that Irish wheel and affixed it to a take-up reel? Would that be 
> anywhere near useful as far as tape-speed accuracy measurement?
>

No.  The circumference (edge) of the wheel is pressed against the tape.  
Tape reels do not rotate at a constant speed, but they run faster or 
slower with less or more tape on the respective reels.  Likewise, the 
Lang strobe on the 350 flywheel stabalizer only works if the shaft is 
not worn.  If there is a groove worn by the tape, the rotational speed 
will be faster.


> Rod, one other thing. The flipside of a quarter-track duped tape 
> should not have pitch differences from the front side. Those tracks 
> were duped at the same time and the tape is from the same point in the 
> duper reel, so you don't have front-to-back issues like you get with 
> splicing together segments of different 15IPS tapes made on an Ampex 
> 300 transport. So if there's a pitch problem, it's likely in the duper 
> master made by the duplicator. Sloppy QC.
>
> -- Tom Fine

There was one dubber which supposedly would not add any wow and flutter 
or speed change from the master.  I forget what it was called, but it 
had a long horizontal capstan and a series of reels mounted vertically 
along it from left to right, including the master.  Any inconstancy in 
that capstan would affect all copies and the master equally.  Anybody 
have any experience with this beast?

Mike Biel  [log in to unmask]
>
> ----- Original Message ----- From: "Roderic G Stephens" 
> <[log in to unmask]>
>
>
> Anybody have one for sale? (Strobe wheel, etc.)
> Rod Stephens
>
> --- On Wed, 3/30/11, Tom Fine <[log in to unmask]> wrote:
>
> From: Tom Fine <[log in to unmask]>
> Subject: Re: [ARSCLIST] Shrunk strobe?
> To: [log in to unmask]
> Date: Wednesday, March 30, 2011, 3:21 PM
>
> Hey, I have one of those Irish strobes, too. Forgot to mention that. 
> It doesn't work very well. The Dubbings disc is much better and 
> precision-feeling. I don't think any of these things are 
> instrumentation-precise but they are precise enough to get you in the 
> ballpark with real-world audio tape recordings.
>
> -- Tom Fine
>
> ----- Original Message ----- From: "Michael Biel" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Wednesday, March 30, 2011 6:09 PM
> Subject: Re: [ARSCLIST] Shrunk strobe?
>
>
>> On 3/30/2011 5:41 PM, Roderic G Stephens wrote:
>>> I know that Tom Fine mentioned that he had an old strobe for 
>>> checking tape speed. Does anyone know of any that are available?
>>
>> In the 50s OrrRadio made an Irish strobe disc on a handle which you 
>> could lightly press onto the outside wrap of the tape on the reel as 
>> it moved. Worked fairly well if you didn't press hard enough to slow 
>> things down. Robbins (I think) made a strobe tape but it was bumpy as 
>> it ran thru the machine.
>>> I think I remember Ampex decks in Hollywood that had a small 
>>> circular strobe that fit on the top of the capstan, but they were of 
>>> bigger diameter than my Teac 2340R.
>>
>> That would make a very small strobe even on the larger capstans of 
>> the 30 IPS versions of the 200 and 300! What I remember is a strobe 
>> that Lang/Pultec had for the flywheel stabilizers of the 350. We had 
>> them on some of the machines at a studio I worked for in the 60s, but 
>> they were useless because some of the stabilizers were so used that a 
>> groove had been worn into the shaft by the tape. (These machines were 
>> used for editing with much shuttling.)
>>
>> Mike Biel [log in to unmask]
>>
>
>