I have been slowly outfitting my lab with dead test equipment purchased at rock bottom prices on Ebay. I buy dead stuff, fix it, then sell enough to pay for it all. That way I can build a nice lab for zero money. Some of my RF test stuff can be seen in the background. All of it is fully functional.
So this time I snagged a Sorensen DCS 600-1.7 power supply for $139 in "AS IS for parts" condition. The pictures on Ebay show more dust than power supply, so there were no bids. I spy two things that will make the power supply appear non functional, so I buy it.
Sorensen DCS 600-1.7 600V Programmable Power Supply Powers on - AS IS for Parts | eBay
It arrives, and I have it running within an hour, and most of that time was spent with a shop vac.
Step 1....serious clean up.
Step 2....consult the manual. I already have it since I already have 3 Sorensen DCS series supplies. I made up a jumper plug according to the picture in the manual since the original is missing.
Step 3.....again, set the internal DIP switches to match the picture in the manual.
Step 4....plug it in and turn it on......It's alive.
Step 5 ........With 600 volts at 1.7 amps......time to blow something up....I connect a dead vacuum tube with only two leads, plate and cathode. I don't even bother to light the heater (filament) it's that dead!
Step 6....put the covers on and add it to my lab collection. I'm going to see if I can steal the GPIB / IEE488 interface from one of my other Sorensens and transplant it into this one......later after I beat on this one for a while to see if it's trustworthy.
So this time I snagged a Sorensen DCS 600-1.7 power supply for $139 in "AS IS for parts" condition. The pictures on Ebay show more dust than power supply, so there were no bids. I spy two things that will make the power supply appear non functional, so I buy it.
Sorensen DCS 600-1.7 600V Programmable Power Supply Powers on - AS IS for Parts | eBay
It arrives, and I have it running within an hour, and most of that time was spent with a shop vac.
Step 1....serious clean up.
Step 2....consult the manual. I already have it since I already have 3 Sorensen DCS series supplies. I made up a jumper plug according to the picture in the manual since the original is missing.
Step 3.....again, set the internal DIP switches to match the picture in the manual.
Step 4....plug it in and turn it on......It's alive.
Step 5 ........With 600 volts at 1.7 amps......time to blow something up....I connect a dead vacuum tube with only two leads, plate and cathode. I don't even bother to light the heater (filament) it's that dead!
Step 6....put the covers on and add it to my lab collection. I'm going to see if I can steal the GPIB / IEE488 interface from one of my other Sorensens and transplant it into this one......later after I beat on this one for a while to see if it's trustworthy.
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I recently repaired a Dell Alienware laptop. It needed a new battery. It was designed by somebody with a sense of humour. To replace the battery in an Alienware laptop you have to remove the back case. Remove the hard disk. Remove the RAM. Remove the SSD. disconnect all the connectors you can see. Remove the keyboard. Disconnect and remove the screen. Remove the mother board. Then replace the battery and put it all back together - if you can remember where it all goes. Jeez.
Reminds me of what a mechanic told me, referring to a car that had come in and needed a new heater matrix. He said after doing the job he was sure that when they built the car, they hung the matrix from a wire then assembled the rest of the car around it, as you pretty much had to dismantle the whole ******* thing to get to it....
When I rebuild my first automatic transmission (about 1976), I borrowed a Polaroid camera and took a picture of each part as I took it out. I numbered each picture so I knew in which order it came out. I reversed the stack of pictures and used them to put it all back together. The surgery was successful and I have done a few transmissions since then.
Today when ripping something apart that I haven't ever seen, I set up a couple of cameras on tripods to watch. I used to shoot video, and sometimes I still do, but I find it better to set the camera to snap a hi resolution still every second or so. Anything unusual gets held up to the camera, and I still keep a spare pocket camera handy for detail shots.
We had a Plymouth minivan with a Mitsubishi 3.0L V6 that we bought new in 1993. The manual said to change the timing belt at 70K miles, so when the clock hit 95K I decided it was time. The dealer quoted $2,000 to change a $30 timing belt, so I borrowed a friends shop manual. Upon looking through the procedure, it took 14 pages of removing stuff before you could even SEE the timing belt, and another 20 to change it.......We traded in the van.
We had a 1984 Dodge Daytona that needed a new AC evaporator. It's in the same air box with the heater core (matrix?). The shop manual started out with "remove the parking brake cable" from underneath the car. You had to start there so that you could eventually get the console out from between the front seats, so that you could take out the stereo, and several other things including the front passenger seat, before you could see that dang box. It looked like the air box was bolted to the firewall before the dash was hung over it. My wife came home in the middle of this, saw the pile of parts in the yard and asked "what have you done to my car?" I did get it all back together, but it killed the whole weekend. Another weekend was killed changing the timing belt in that car. Minor surgery compared to the minivan.
RF test equipment all bought from company scrap auctions, Ebay and hamfests, usually broken them repaired:
I have an over supply of RF signal generators, all HP. Three 8642's (one semi dead) an 8643, an 8644, and four 8664's. These were the lowest close in (25 KHz or less) phase noise signal generators HP ever built (including their current stuff). I have an 8753C Network Analyzer, an 8594E Spectrum Analyzer, an 8352B VCO/PLL signal analyzer (plots phase noise), an E4406A VSA Transmitter Tester (grabs a 10 MHz chunk of spectrum and does FFT with milliHertz resolution) and a 436A RF power meter.
Power supplies:
The Sorensen DCS 600-1.7, 3X sorrensen DCS 33-33E (one still dead), one Sorensen QRD 20-4, one Sorensen LS30-3, an HP6448B, a Fluke 407D, and a Knight KG664.
Scopes:
Tektronix 2232, Tektronix 2335, Rigol DS2072A bought new and "modified."
Misc:
HP 8903A Audio Analyzer, HP 3478A Multimeter, HP3311A Function Generator and two HP204C Audio Oscillators, two HP331A distortion analyzers, and various cheap hand held multimeters.
Shipping to get stuff here often cost more that the cost of the unit. I try to buy stuff cheap, with the idea that they are truly a box full of spare parts. That's how I got so many signal generators. As I got more familiar with the 8643,43 and 64's (all similar), I learned how to fix the individual modules (schematics are not available). I wound up fixing all the "parts units" and have since sold a few at hamfests. I made 2 good 8642's out of 3 parts units, and could probably fix the 3rd one given time and motivation. It has a weird intermittent problem, and is missing a few cosmetic items and one side panel, thus it will never be worth selling, so therefore doesn't get fixed.
A while back I fixed my microwave. Looked like the HV rectifier blew, destroying all markings. I went to a recommended appliance parts shop and bought all parts required, as lightbulb and fan screen were also broken. Total bill was over $50. After I fixed it all, I realized I paid over $30 for a common diode that had spade terminals on it. Won't be making that mistake again.
The discussion on carbs was interesting to me as I am trying to fix up my old dirt bike. Nowadays some hobbyists just replace the carb with a Chinese knockoff as it only costs a little more than finding a vintage rebuild kit. Yes, a Chinese knockoff of a current production carb outperforms the vintage Japanese original.
The discussion on carbs was interesting to me as I am trying to fix up my old dirt bike. Nowadays some hobbyists just replace the carb with a Chinese knockoff as it only costs a little more than finding a vintage rebuild kit. Yes, a Chinese knockoff of a current production carb outperforms the vintage Japanese original.
Zenith produced the carbs for the E type in their Depford , S. London plant in the 60's
The house wiring in my sister's houseboat after a "contractor" butchered a rewiring job. That man should never be allowed near electricity. Disconnected safety grounds, switches that don't switch anything, the bathroom circuit wired to two different breakers (switch on either one powers the circuit), outlets with hot going to both prongs. (US 120V service) A disaster waiting to happen. He moved to the out of the country shortly after this job was "completed."
Lot of companies named "Zenith".
Zenith Carbs no relation to Zenith Radios, if that is what you were thinking.
I know the Zenith jugs from many tractor-type engines. They were also used on some Ford Ts and many Ford As. H-D motocycles. A lot of WWII aircraft engines. What is amazing is that they are still in business and still make up-drafts (though I do not see the very large one).
I last fixed one of my 8 track tapes (Led Zeppelin II)
The person I got this from on ebay had this written "RE-CONDITIONED AND PLAYS WELL"
Well obviosuly he didnt check it after his conditioning!!
The pad is good but the sensing foil he put on left a piece of the tape dangeling on the back side and it would not play well @ all.... It kept stopping,etc....
I just put a piece of tape over it to keep it tightly against the tape so it wouldnt interfere....
I dont get it..... People "re-condition" this stuff but they dont care enough to make sure it works right??
I dunno..........
(Led Zeppelin II)The person I got this from on ebay had this written "RE-CONDITIONED AND PLAYS WELL"
Well obviosuly he didnt check it after his conditioning!!
The pad is good but the sensing foil he put on left a piece of the tape dangeling on the back side and it would not play well @ all.... It kept stopping,etc....
I just put a piece of tape over it to keep it tightly against the tape so it wouldnt interfere....
I dont get it..... People "re-condition" this stuff but they dont care enough to make sure it works right??
I dunno..........
Non audio: i just put a new SSD in an old dell laptop and reinstalled the OS for a friend so he can use it for some more years (he just use it to surf arround, email and spotify).
Audio: a month ago i checked up a diy tube guitar amp of a jazzguitarist i know and replaced a gain potmeter (because it was making noise) and some elco caps (that were going down) in the psu. I also checked the tubes, but they are still in spec. I also had to fix a jack connector that gave noise (resolder the connections). He has a busy summer and wanted his amp to be ready for that, and most guitar amp techs don't want to touch a custom amp it seems (that why he came to me even if i'm not really into guitar amps).
Audio: a month ago i checked up a diy tube guitar amp of a jazzguitarist i know and replaced a gain potmeter (because it was making noise) and some elco caps (that were going down) in the psu. I also checked the tubes, but they are still in spec. I also had to fix a jack connector that gave noise (resolder the connections). He has a busy summer and wanted his amp to be ready for that, and most guitar amp techs don't want to touch a custom amp it seems (that why he came to me even if i'm not really into guitar amps).
1) Window wells -- weren't draining so when we had a big rain the basement flooded. Put up a plastic gardening barrier so the water would have to rise an inch above the lip of the well and gravel to slow the water.
2) a fellow's SG165 Sencore AM-FM alignment tool -- just needed some patience in getting the tuning correct.
2) a fellow's SG165 Sencore AM-FM alignment tool -- just needed some patience in getting the tuning correct.
Hi Jack,
That's pretty cool!
The last thing on my bench was an Adcom GFA-565. Cleaned up some work done previously and did some upgrades that improved performance a fair amount.
I will be doing cassette decks again, so I still need the head height gauge (two piece jig) and some calibration tapes in good condition or new. Please let me know if anyone has some of these gathering dust. I wouldn't say no to the Nakamichi set of jigs and tapes as I used to have them and am trained on that product line. That includes the computer interface for the 1000ZXL.
-Chris
That's pretty cool!
The last thing on my bench was an Adcom GFA-565. Cleaned up some work done previously and did some upgrades that improved performance a fair amount.
I will be doing cassette decks again, so I still need the head height gauge (two piece jig) and some calibration tapes in good condition or new. Please let me know if anyone has some of these gathering dust. I wouldn't say no to the Nakamichi set of jigs and tapes as I used to have them and am trained on that product line. That includes the computer interface for the 1000ZXL.
-Chris
Citation 7.0 preamp / HT processor
Power supply when in stand by is fully on and cooks the PS board area.
In hot environments it will literally desolder transformer leads and you get dropouts in voltage.
Lesson learned and replaced all PS caps and diodes and keeping it turned off completely when not in use.
Old school fosgate inspired HK style
Very nice sound quality though
Regards
David
Power supply when in stand by is fully on and cooks the PS board area.
In hot environments it will literally desolder transformer leads and you get dropouts in voltage.
Lesson learned and replaced all PS caps and diodes and keeping it turned off completely when not in use.
Old school fosgate inspired HK style
Very nice sound quality though
Regards
David
Does it count if I just kept pressing buttons and it fixed itself? LG washing machine wouldn't drain. Manually drained water from the tub and cleaned the drain filter, ran a cycle, tub did not drain and there was a strong smell of over-heated windings. Tried again the next day and put a tub-cleaner tablet in the cycle, and it drained. Did that 3 times and called it "fixed". I would like to get the pump out and disassemble and clean it but it's really hard to get at so will wait for next failure.
My last difficult repair was an old 1980's Maplin 50 watt amplifier.
I bought it off ebay to repair.
It worked but was very distorted.
I got the scope to it and the volts around one transistor were a bit suspect.
So to be thorough I checked all the components on the pcb and they seemed fine.
The suspect transistor diode checked fine.
But I still kept coming back to this one transistor.
It then suddenly hit me that its diode check was in fact the wrong way around.
Someone had fitted a pnp instead of an npn.
And just to make it harder the transistor number had rubbed off.
The right transistor was almost impossible to get but I tracked one down on ebay.
Popped it in and everything was spot on.
I bought it off ebay to repair.
It worked but was very distorted.
I got the scope to it and the volts around one transistor were a bit suspect.
So to be thorough I checked all the components on the pcb and they seemed fine.
The suspect transistor diode checked fine.
But I still kept coming back to this one transistor.
It then suddenly hit me that its diode check was in fact the wrong way around.
Someone had fitted a pnp instead of an npn.
And just to make it harder the transistor number had rubbed off.
The right transistor was almost impossible to get but I tracked one down on ebay.
Popped it in and everything was spot on.