home *** CD-ROM | disk | FTP | other *** search
- @BEGIN_FILE_ID.DIZBlue Box plans
- @END_FILE_ID.DIZ
-
- $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
- $ $
- $ BLUE BOX PLANS! $
- $ --------------- $
- $ $
- $ Edited and Uploaded by: $
- $ $
- $ $
- $$$$$$$->The Spirit Of Radio<-$$$$$$$$$
- $ $
- $ Written by: $
- $ $
- $ Mr. America from Osuny BBS $
- $ $
- $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
-
- This file will explain the construction, troubleshooting,
- This design will make them last 10 months!!!!!! But
- nevertheless, don'tforget to put in aswitch for on and off. Ok
- let's build the two VCO'S andcalibrate the unit before we get to
- the keyboard construction.
-
-
- VCO CONSTRUCTION
-
- TOOLS REQUIRED
- 1 ocilliscope(optional but not req)
- 1 Freq. counter (REQUIRED)
- 1 Volt meter " " "
- Electronics tools (Pliers, drll, screwdrivers, etc.)
-
-
- PARTS
-
- R1 1.5K RESISTOR 5%
- R2 1K RESISTOR 5%
- C1 .1uf ELECTROLYTIC CAPACITOR 16VDC
- C2 .01uf " " (MYLQR) 16VDC
- C1 2207 VCO CHIP BY EXAR ELECTRONICS
-
- Remember the above only says VCO#1 but the same is for VCO#2
-
- R3-R4 150 OHM RESISTORS 5% .
- C3-C4 .1 uf ELECTROLITIC CAPACITOR .
- 10VDC .
-
- P1-P10 200K TRIMMER POT - 20 TURNS DIODES USED IN THE KEYBOARD
- ARE 1N914 TYPE(40 OF THEM) & 13 SWITCHES FOR THE KEYBOARD SPST
- MOMENTARY.
-
- SPKR YOU CAN USE A TELEPHONE SPEAKER FOR THIS (IT WORKS BEST) BUT
- REMEMBER TOTAKE OUT THE DIODE THAT IS CONNECTED ACCROSS IT.
-
-
- IMPORTANT NOTES
-
- 1. DO NOT USE ANYTHING ELSE OTHER THAN A MYLAR CAPACITOR FORC2.
- 2. PINS 10,9,8 SHOULD BE TIED TOGETHER AND BE LEFT FLOATING.
- 3. ALL RESISTORS SHOULD BE 5%! NOTHING ELSE!
- 4. A TELEPHONE SPEAKER GIVES THE BEST RESULTS.
-
-
- TROUBLE SHOOTING
-
- By now you should have constructed the two VCO'S on a bread board
- or anything that pleases you. Check for cold solder
- joints,broken wires,polarity of the battery, etc. Before we
- apply power to the VCO'S we have to adjust the pots for their
- half way travel point. This is done by turning them 21 turns to
- the right and then 10 turns to the left. Do the same for all ten
- of them.
-
- Now apply power to the unit check to see that you have power in
- the chips by putting the positive lead of your volt meter on pin
- 7 andthe negative lead on pin 12. If you do not have anything
- there turn off the unit and RECHECK THE WIRING.
-
- When you get the right voltages on the chips, connect a diode to
- a piece of wire (look at fig. 2 for the orientation of the diode)
- from round to any pot at point T (look carefully at the schematic
- for point T it is labeled T1-T10 for all pots). You should be
- able to hear a tone, if not disconnect the lead and place the
- speaker close to your ear and if you hear a chirp-like sound,
- this means that the two VCO'S are working if you don't,
- it means that either one or both of the VCO'S are dead. So in
- this case it is always good to have an ocilloscope on hand.
- Disconnect the speaker from the circuit and hook the ocilliscope
- to 1 of the leads of the speaker & the ground from the scope to
- the ground of the battery. Connect again the ground lead with the
- diode connected to it from ground to any pot on the VCO that you
- are checking and you should see a triangle wave if not turn the
- pot in which you are applying the ground to until you see it.
- When you do see it do the the same for the other VCO to makesure
- it is working. (amplitude is about 2VAC). When you get the two
- VCO's working you are set for the adjustment of the individual
- spots.
-
-
- ADJUSTMENT
-
- Disconnect the speaker from the circuit and connect a freq.
- counter (the positive lead of the counter to one of the speakers
- leads that belongs to VCO#1 or connect it to pin 14.
-
- Connect the negative lead to the battery negative and connect the
- jumperlead with the diode from ground to pot number 1.T1 (the
- first pot number 1 point T1). If you got it working you should
- hear a tone and get a reading on the counter. Adjust the pot for
- a freq. of 1700hz and continue doing the same for pots 2-5
- except that they get different freqs. which are:
-
- : $$$$$$$$$$$$$$ :
- : $ $ :
- : $ P1 1700hz $ :
- : $ P2 1300hz $ :
- : $ P3 1100hz $ :
- : $ P4 900hz $ :
- : $ P5 1500hz $ :
- : $ $ :
- : $$$$$$$$$$$$$$ :
-
- Now disconnect the freq. counter from the speaker lead of VCO#1
- or from pin (which ever you had it attached to at the beginning)
- and connect it to the speaker lead of VCO#2 or to pin 14 of VCO#2
- and make the same adjustments toP6-10.:
-
- : $$$$$$$$$$$$$$$ :
- : $ $ :
- : $ P6 1100hz $ :
- : $ P7 700hz $ :
- : $ P8 900hz $ :
- : $ P9 2600hz $ :
- : $ P10 1500hz $ :
- : $ $ :
- : $$$$$$$$$$$$$$$ :
-
- When you finish doing all of the pots go back and re-check
- them.
-
-
- KEYBOARD
-
- IF YOU LOOK AT FIG-2 YOU WILL SEE THAT THE KEYS ARE
- SIMPLE SWITCHES. CONNECTED TO A GROUND AND TWO DIODES ON THE
- OTHER END. THESE DIODES ARE USED TO SIMPLIFY THE CONSTRUCTION OF
- THE KEYBOARD BECAUSE OTHERWISE THE DISTRIBUTION OF THE GROUND
- SIGNAL FOR BOTH VCO'S WOULD HAVE BEEN DONE MECHANICALLY. THE
- DIODE WILL GO TO VCO#1 AND THE OTHER WILL GO TO VCO#2. FIG-3
- SHOWS THE ARRANGEMENT OF THE KEYS ON THE KEYBOARD.
-
- BELOW IS A TABLE THAT WILL HELP YOU CONNECT THE KEYS TO THE
- REQUIRED VCO'SPOTS.
-
- <------------------------------------->
- < >
- < (-FIG 2-) >
- < >
- <-----!-----!--------!--------!------->
- < ! ! ! ! >
- < TO ! TO ! FREQ ! FREQ ! KEY >
- < POT ! POT ! OUT: ! OUT: ! >
- < ON ! ON ! ! ! >
- < VCO1! VCO2! ! ! >
- <-----!-----!--------!--------!------->
- < 1 ! 06 ! 1700hz ! 1100hz ! C >
- < 2 ! 10 ! 1300hz ! 1500hz ! 0 >
- < 1 ! 10 ! 1700hz ! 1100hz ! E >
- < 4 ! 07 ! 0900hz ! 0700hz ! 1 >
- < 3 ! 07 ! 1100hz ! 0700hz ! 2 >
- < 3 ! 08 ! 1100hz ! 0900hz ! 3 >
- < 2 ! 07 ! 1300hz ! 0700hz ! 4 >
- < 2 ! 08 ! 1300hz ! 0900hz ! 5 >
- < 2 ! 06 ! 1300hz ! 1100hz ! 6 >
- < 5 ! 07 ! 1500hz ! 0700hz ! 7 >
- < 5 ! 08 ! 1500hz ! 0900hz ! 8 >
- < 5 ! 06 ! 1500hz ! 1100hz ! 9 >
- < - ! 09 ! ------ ! 2600hz ! X >
- < ! ! ! ! >
- <------------------------------------->
-
- REMEMBER THAT IN FIG-2 IT'S THE SAME FOR EACH KEY EXCEPT THE "X"
- KEY, WHICH ONLY TAKES ONE DIODE.
-
-