"Tom Evans, AG9X" <[EMAIL PROTECTED]> made an utterance to the drakelist gang ---------------------------------------------------------------------- Kevin,
Here's the PS-7 manual: http://www.wb4hfn.com/DRAKE/DrakeManuals/PS7/Manual_PS7.htm Here's a better version of the PS-7 schematic: http://www.dproducts.be/drake_museum/images/PS7schematic.JPG An even better version of the PS-7 schematic: http://www.geocities.com/capecanaveral/hangar/6441/drake/ps7.jpg Here are some PS-7 troubleshooting tips: http://www.zerobeat.net/drakelist/tr7moremods.html #3, #16 and #17 pertain to PS-7 Good luck, Tom, AG9X On 3/15/06, Kevin LaHaie <[EMAIL PROTECTED]> wrote: > > Kevin LaHaie <[EMAIL PROTECTED]> made an utterance to the drakelist gang > ---------------------------------------------------------------------- > Hello > > I have inherited a TR7/PS7/MN7 station, which was not working, but > rumored to have a power supply problem. Turns out it was the power > supply regulation board was shutting down the supply after reaching > about 4 volts.. By removing a feedback lead, the supply would regulate > to 13.5v. I replaced the key components on the board - the regulator > chip (NTE equivalent), a couple of transistors, a zener, resistor values > all check OK, so the problem is not the 723 chip, but some part of the > over-voltage protection function. It is not the is large clamping diode > that grounds the supply in case of a runaway, but somewhere in the > 'feedback loop' to the 723. > > 2 Questions: > > 1. anybody have an idea what could be causing this? I have not replace > ALL the parts (yet!) > 2. Does anybody know where to get a higher quality schematic scan - the > one I have is pretty 'muddy', with some voltages at key points on the > circuit being unreadable, which will no doubt lead me to the solution. > > Thanks in advance to the members of a great list! > > 73 Kevin K7ZS > ---------------------------------------------------------------------- Submissions: [email protected] Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net ----------------------------------------------------------------------
