Ampex ATR 102 calibration procedure Help!! :)

[thekid777]

Hi Mr,
I have the full manual to do the calibration of the machine and already calibrated the I/O modules without any problem
but don't remember in which order next steps should be done.
I don't even remember how to check azimuth? it is both tracks that are checked simultaneously to put them in phase?
Could you help me?
Thanks!!
Best

 

[fazer]

I'm doing this from memory:  Turn off ATR and demag and then clean heads with 90% or better Alcohol or use a good head cleaner.

I'm assuming your erase current is adjusted  already if your tape is not erasing then reset bias and erase according to the ampex manual recommendations.   
I'm also assuming your tension is setup right.  You need fish scales and maybe a tentelometer to set up tension.      Everything as far as tension and bias/erase current, need to be correct for the alignment below to work correctly.


General Recorder Alignment.

Azimuth:      Need a Cal tape full track Play 10k  freq from cal tape in reproduce mode on recorder.  With scope in x-y mode plugged into Atr102's output, adjust Azimuth screw/allen hex on repro  head playback and  watch the pattern for most in phase on scope.  scope displays a 45 degree line from lower left to upper right.  Hopefully this just needs touched up and not peaked.  It should react quick with a minor turn left or right. does not need many turns unless heads are replaced and need a full set up.

Playback Repro  Play your 1k test tone from cal tape and set for flux level. If its a + 3 tape 261 nw/m2 and you want +3 record level ,then set to 0vu on meter.  If you want +6 then set to -3 on VU.  adjust offset to adjust record level desired.  Then adjust the 10k with Playback Hi freq at the correct speed(ips pot) to same offset as 1k tone.

Record: Place record tape on and adjust bias.  Usually 3db over at 10k so 10k test tone and adjust bias to peak and then increase till it falls 3 db from the peak.  then send 1k from console VU meters at 0vu. Adjust record level to 0 vu on recorder meter. 

Send 10k from console at 0 vu and adjust Hi Freq record (correct Ips pot) to 0 vu on recorder meter. 
Send 100z from console and adjust Low Freq Playback compensation to 0 VU. 

Record 1k 10k 100hz tones on tape for a playback reference. 
Sync adjust.  Set azimuth from 10k tone same as repro was adjusted.  Then playback tones in Sync mode and  adjust  each tone to 0 VU  from Sync playback controls just like Repro  above,  only now from your recorded tones not your cal tape.

Start recording music.  Listen for Input to Output  accuracy.
Good Luck

 

[pvision]

You have to be careful when changing azimuth. At 10k it's a very touchy adjustment. You're comparing the phase relationship of two 10k sine waves by tilting a head. The physical gap between two adjacent peaks is not large (you could work it out quite easily) and it's possible to miss the peak and find an adjacent one. I was always told to keep well alone unless you know what you're doing

If you have to reset it, check it at 1k then at all other ascending frequencies on your test tape, to minimise the risk of getting it wrong

Bias both channels the same before looking at record head azimuth

Nick Froome

 

[radardoug]

I agree with pvision, but also, use the scope in two channel mode. For azimuth, start at the lowest frequency on the test tape. Verify that phase is correct. Then move up through the tones, each time verifying that phase and azimuth are correct. Its very easy for the non-competent to get azimuth wrong, and be off azimuth everwhere but at 10K! Once you have done a repro alignment, do azimuth in record for the record head by the same method. Variations in record eq and bias will change azimuth. DO NOT just do azimuth in selsync.