PL7000S2

[George S.]

Got the Sendust head installed. Penetration, zenith, height, and guide alignment look good.
The Sendust head has a tape guide the Ferric didn't have.
Going to see if I can allow it to remain rather than disturb the retaining screw and green adhesive.
Only external adjustments on this transport are the head azimuth and supply side guide.

 

[George S.]

Success. Finally able to set Azimuth.
No way the old head was capable of this.
Going to try to align this deck with no component value changes on the boards.
Later.
Listening to King Weed......Smoke Over Doom.

 

[George S.]

Fired up the Han-D-Mag and bulk erased the four cassette types the recording section will be calibrated to.
The tapes vibrate violently within the shell, it's a beast,
The flat bottom is configured for bulk erasing.
Also comes in a 220 VAC version.

 

[George S.]

Progress.
Running through the playback alignment a second time for precision.
Fine tuning the tape path using magnification and scope.
I really prefer adjusting azimuth using superimposed sine waves on the digital scope.
Very easy to observe phase as the waves invert during adjustment. VERY apparent when the channels are in phase, easy to be fooled when they're not.
Ran a frequency response test of the Playback EQ circuit using the QA403 and HPR frequency burst tape.
It's down appx 2 dBV at 10 kHz from were the service manual wants it.
Thinking I might gain that with fine tuning the tape path. I did flip the tape and retest. Spot on, been very impressed with the HPR tapes.

 

[derek92994]

Sure Enjoyed reading this thread. Amazing effort to the finest detail, I'm impressed George.
The mechanism looks tough, and the electronics just plain scary Gotta dig those Nichicon Fine Gold Caps.
I think Sendust type heads are said to be one of the longest lasting.

 

[laatsch55]

Second that. I think seeing the progress on a day to day basis we don't appreciate the effort and tenacity associated with this project. George, I'm fuckin impressed. The amount of research done on your own is a testament to your commitment....excellent example of how to eat an elephant...

 

[George S.]

Playback is aligned a second time.
Testing the Dolby alignment with the HPR Dolby Level tape by measuring directly at the chips soldered in test leads.
The PL manual uses two alignment steps to calibrate the Dolby Board accurately. No tape.
Going to get away from this for awhile, road trip time.
Need to learn more about tape levels.