R to R Guy
New member
I am new here and have a few Quad items buy mainly vintage audio from the 70's. I am needing help already with a Quad RTR! I recently picked a Quad Akai GX 280D ss tape deck, dead but started working upon cleaning the 2ch/4ch switch and others. It now which works fine at 7 1/2 ips and forward but lacks REV and 3 3/4 ips which I have been attempting to fix.
Two problems remain.
Problem 1: No REV
I have resoldered the past thru connectors with wire inserts. I have cleaned the contacts on the two REV relays. I checked the transistors and TR 111 showed bad. It is the one TR mainly involved with the REV. I went ahead and and changed TR1 and TR111.
I plugged in the circuit board and after pushing the tape recorder ON button only, the tape started running in REV, with no light on REV button, but a light on the FWD button! None of the buttons work including the stop. I tried this several times, same result. I unsoldered TR111, plugged in the board and everything works except REV as before. I tried reversing C and E on TR111 and the deck runs in only REV but STOP button works. So what I have is operation is normal except no REV with TR111 in (although bad operation) or no REV without TR111 installed.
Any body got some ideas to solving this mystery?
Problem 2: 3 3/4 ips speed is too fast
I had changed out TR209 when I had no 3 3/4 ips speed and now have 3 3/4 ips speed back but sounds speeded up or too fast. I made a timing tape by measuring 225 inches of tape and marked with a Sharpie. With 225 inches of length, 3 3/4 ips is exactly 60 secs and 7 1/2 is exactly 30 secs.
I timed 3 3/4 ips speed and found it to be at 43 secs, too fast. I should be 60 sec. Additional info 7 1/2 ips is right on 30 sec.
I located L1 inductor, which is used to adjust 3 3/4 speed, found out which way to turn and using a non conducting tool, increased the speed by turning L1 until I got to 56 secs and ran out turns at 6 turns. Checked 7 1/2 ips before and it was right on 30secs but a check when L1 was maxed out at 3 3/4 ips and 56 secs, 7 1/2 was 32 secs. So I backed L1 back 6 turns and have 7 1/2 ips back to 30 secs but 3 3/4 ips is back to 49, back to ground zero with 3 3/4 too fast.
Any ideas what to do next?
Thanks for your attention and help.
Charlie
Two problems remain.
Problem 1: No REV
I have resoldered the past thru connectors with wire inserts. I have cleaned the contacts on the two REV relays. I checked the transistors and TR 111 showed bad. It is the one TR mainly involved with the REV. I went ahead and and changed TR1 and TR111.
I plugged in the circuit board and after pushing the tape recorder ON button only, the tape started running in REV, with no light on REV button, but a light on the FWD button! None of the buttons work including the stop. I tried this several times, same result. I unsoldered TR111, plugged in the board and everything works except REV as before. I tried reversing C and E on TR111 and the deck runs in only REV but STOP button works. So what I have is operation is normal except no REV with TR111 in (although bad operation) or no REV without TR111 installed.
Any body got some ideas to solving this mystery?
Problem 2: 3 3/4 ips speed is too fast
I had changed out TR209 when I had no 3 3/4 ips speed and now have 3 3/4 ips speed back but sounds speeded up or too fast. I made a timing tape by measuring 225 inches of tape and marked with a Sharpie. With 225 inches of length, 3 3/4 ips is exactly 60 secs and 7 1/2 is exactly 30 secs.
I timed 3 3/4 ips speed and found it to be at 43 secs, too fast. I should be 60 sec. Additional info 7 1/2 ips is right on 30 sec.
I located L1 inductor, which is used to adjust 3 3/4 speed, found out which way to turn and using a non conducting tool, increased the speed by turning L1 until I got to 56 secs and ran out turns at 6 turns. Checked 7 1/2 ips before and it was right on 30secs but a check when L1 was maxed out at 3 3/4 ips and 56 secs, 7 1/2 was 32 secs. So I backed L1 back 6 turns and have 7 1/2 ips back to 30 secs but 3 3/4 ips is back to 49, back to ground zero with 3 3/4 too fast.
Any ideas what to do next?
Thanks for your attention and help.
Charlie