The AKAI 1720 model reel to reel tape recorder described in this Manual is quite an old unit - circa late 1960's. As a consequence, the description of the mechanical details - and adjustments thereof - is quite critical. The manual does this quite well. The schematics are also well presented and have detailed PCB overlays. Probably the only negative is that some half-tone detail has been lost from the original manual as it has been scanned in simple B&W.
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Text excerpt from page 12 (click to view)
ITEM HEIGHT (HIT) 1. 2. 3. 4.
ADJUSTMENT PROCEDURE Receive NTSC signal. Select the "FULL" mode by PIC SIZE button on Remote Control. Call up the adjustment mode display and select the item HIT. Press the VOLUME s or t button to get the picture so that top and bottom of video signal begin to lack. 5. Press the VOLUME s button to advance the data by 8 steps. Note: Check the vertical picture position is correct. Adjust the data of height after vertical linearty. 1. Receive cross-hatch pattern. 2. Call up the adjustment mode display, then select the item VLIN. 3. Press the VOLUME s or t button to obtain the picture of the best linearity. 4. Then readjust the item HIT.
VERTICAL LINEARITY (VLIN) (FULL mode only)
WHITE BALANCE (RCUT) (GCUT) (BCUT) (RDRV) (BDRV)
1. Press RESET button on TV or remote hand set. 2. Call up the adjustment mode display, then adjust the data of items RCUT, GCUT and BCUT to �80�. 3. Press TV (ANT)/VIDEO button on TV. 4. Gradually rotate R, G and B SCREEN volume of FOCUS PAC (page 8) clockwise or counterclockwise until the raster appears slightly on the CRT through the each lens, and leave them. (Look into the lens in order to check the raster.) 5. Press TV (ANT)/VIDEO button on TV again. 6. Exit from service mode. 7. Receive white laster pattern signal, and adjust the contrast to the minimum to make white picture to low light. 8. Adjust the data of items RCUT, GCUT and BCUT for low light area. 9. Adjust the contrast to the maximum to make white picture to high light. 10. Adjust the data of items RDRV and BDRV Controls for proper white-balanced picture in high light area. 11. Check the white balance in both low and high light areas. If necessary, perform again steps from 7 to 9.