Looking for some guidance on my "major" endeavor on shoestring budget...haha...
I have a Harris Stereo 80 console, that I fired up for the first time to take stock of just where I stood. Unit was pulled
from working station I'm told a few years ago and has been idle.
I began fixing a few cosmetic problems like the hinge joints on the front panel, then replaced the rear panel long flex hinge with two actual small door hinges. Pulling the modules I found two edge card connectors broke under the Program and Monitor amp bays. I had some plastics glue around so gave it a shot gluing them back together. Thought it was at least worth a try, and so far has seemed to hold up, and it appears I was careful enough that I didn't alter the contacts in each...Doing more studying (I don't have any experience in broadcast consoles at all, but I've dabbled with electronic repairs from a "jackleg" point-of-view, and had some decent success, all coming with great help from friends and net folks) I looked for obvious signs of potential problems and all looked ok.
Initial test: Power applied and all seemed fine--no smoke, fire...
First thing I noticed was left meter needle was bouncing wildly and intermittantly. I started doing some prodding and poking around and somehow jostling the Left Program Amp module I suddenly noticed a wiff of white smoke rise from it, so I shut down. Can't remember exactly the sequence of events, but at some point I moved the Left Monitor amp (just beside it) into the Program bay, run a feed from a boom box headphone out into the Turntable inputs, and then attached a couple of speaker lines to the Program Out pegs on each side. Firing up again, I found level coming to both meters, and then sound to both speakers. Not content, I had to poke a little more, and ended up with another amp smoking same way, and audio quit to the left side.
After shut down, I spent more time checking out the connnectors I had repaired and they seemed fine. Clear and clean, wires intact, and voltages of 45vdc measuring at the correct terminals. Since I don't much at all about electronics, I again went into "jackleg" mode, and reinserted one of the bad amps atop an extender card, fired up, and then tried to take measurements again. Baffling to me is the fact that the voltages at just about any place where there should be some was around 3vdc or lower. Am I seeing something shorted in my amps that is cutting the power that originates from the connector? I was expecting to still see normal voltages, but to see reduced amounts really threw me for a loop.
I then pulled the Monitor amp from the right side and put it in the Left Program bay, fired up, and audio is good on both sides. So I know that I've screwed both earlier amps..duh! But I don't believe too difficult to repair, since they are older technology, I do know what transistors, caps, resistors, etc. are, and can replace them with no problems. What I don't know (again doh!) is the theory behind it, and how to track down the problem area. While I'd love nothing more than to be able to take training to do better, at my age now, it's pretty much impossible. But given that, no matter, I still get enjoyment out of trying to figure my way around these things. Again, that's only been made possible by the great folks who have guided me thus far so that I could make a variety of things work again.
I have schematics, and have been doing all I can to try and understand them and relate. But I know that without knowledge of how and why the parts work as they do, I'm behind the eight ball.
This unit has way more features than what I need, but it fits exactly what I want to achieve. (will explain shortly)
Trying the Cue function on the TT input I'm testing with, I get nothing on the internal front panel speaker. Digging around I can't see any obvious reason why, and just reaching in to accessible points on the Cue Amp with meter leads, I'm getting what I think are normal readings...so I'm stuck there for the moment. Also, I have no working lights on the meters (I would guess that all four bulbs are no good) but I get some odd readings of voltage between them. I know the circuit says 65vdc of the supply goes to them, but the most I've seen I think is 33v on the socket contacts.
This board is important to me as I'm in the process of starting an internet streaming station, but unlike most others, my goal is to mimic an actual station, complete with all the elements that made community radio what it was when I did a stint at it in the late seventies. I've missed that for so many years, and finally found a way I think I can make a positive change. My focus in on my local community-not the world. Silly as it might be, the console is important because I want to preserve as much of the past as I can, and I enjoy the rotary pots and such. I know that some of today's technology I'll have to embrace, and that's fine, but my console will be my focus (I've even built from scratch two turntables to mimic a Russco...look pretty good if I say so myself! But just for effect)
Any help and guidance would be much appreciated in my efforts.