You know, it isn't always electronics that lands on the bench. This time, because there is nowhere to buy a ready made crate for a large piece of art, you get to do it yourself. I am only mentioning because as always, the damned crate has cost a pretty penny to make solid enough to send this picture. Just the glue involved has been more than expected. The only real disappointment so far is the nearly finished product that I wouldn't dream of taking a picture to show off to anyone, but here is the enlarged photo that I am sending on a trip.
Attachments
As nice as the Fluke is, I almost hate to admit that I use it the most for testing capacitor leakage. It handles any voltage that I want, set the current control at halfway and you have around 10-15 mA current limit. I made a little box (below) that I use for charging up to four at a time and easily test & discharge individually. The TE that I work on tends to have a lot of the large screw terminal capacitors and, for them, the leakage current going high is one of the most reliable signs of failure or about-to-fail. The Fluke lets me always be able to test them at their rated voltage which is a requirement for leakage testing.
lol!
Well Hal, I use an HP 6186C for that task. I'll put the 34465A or 34461A in series to measure leakage current if it is critical. So you aren't crazy at all.
I could use the Data Precision 6200 but the 6186C has a current limit that is adjustable and the meter will read it. The 34465A reads very low currents, so I can check film with it. I guess I could drag out the Fluke 5100B if I really needed to do that for higher voltages.
Isn't the discharge hard on the switches? You would need resistance in series for sure.
Well Hal, I use an HP 6186C for that task. I'll put the 34465A or 34461A in series to measure leakage current if it is critical. So you aren't crazy at all.
I could use the Data Precision 6200 but the 6186C has a current limit that is adjustable and the meter will read it. The 34465A reads very low currents, so I can check film with it. I guess I could drag out the Fluke 5100B if I really needed to do that for higher voltages.
Isn't the discharge hard on the switches? You would need resistance in series for sure.
Yes, I they discharge through large 1K resistors. The setup works nice for me... Patch the supply in, connect a meter to the current terminals and you are good to go. I'll usually connect a second meter to measure the actual voltage as the caps charge as eell
My old drafting table is now my workbench, I'm just getting my feet wet in electronics.
I have restored a total of four 1960's era amps & preamps, this will be number five. A 1966 Sherwood integrated amplifier that someone attempted to get up and running but apparently gave up. It will keep me busy for the next few weeks while I take one bite at a time. I'm going through the schematic and putting together a list of components, verifying against the amp as I go.
I have restored a total of four 1960's era amps & preamps, this will be number five. A 1966 Sherwood integrated amplifier that someone attempted to get up and running but apparently gave up. It will keep me busy for the next few weeks while I take one bite at a time. I'm going through the schematic and putting together a list of components, verifying against the amp as I go.
You have a good start.
Those small capacitors across the terminals of the multisection caps. Don't ever do that (like someone has). You have to remove the old capacitor completely and either replace it with the same style, or figure out a solid way to mount separate capacitors. You can use terminal strips, or a PCB. Don't allow them to just hang there.
When one section of a multisection cap fails, the others will follow. They may short, so completely remove the old part. The issue is that the lugs are used as tie points very often, so you need terminal strips for any other components that were attached to the lugs.
-Chris
Those small capacitors across the terminals of the multisection caps. Don't ever do that (like someone has). You have to remove the old capacitor completely and either replace it with the same style, or figure out a solid way to mount separate capacitors. You can use terminal strips, or a PCB. Don't allow them to just hang there.
When one section of a multisection cap fails, the others will follow. They may short, so completely remove the old part. The issue is that the lugs are used as tie points very often, so you need terminal strips for any other components that were attached to the lugs.
-Chris
Will do, thank you for the suggestion. It all looks very wonky, one of the new caps even has a dent in it.
I’m taking a break from audio and working on a 28 foot tall abstract sculpture of Freda Kahlo.
BTW guys, if you ever get a 'great idea' like I did about shipping a framed photo across the state/continent, please pause a moment and consider the cost of everything involved. Might be obvious to some, but it seemed fairly easy and something that I could do. Two words,,, never again.
Go for it. Our local "Truth is Beauty" is 54' tall. it really changes your perspective.
Little bit of board design. A tad more complicated than most of my amps, but all through-hole. It makes the most god-awful noises though.
How many layers Suzy? I am guessing 6? Two power planes and 4 routing layers.
I see it’s a new design by your date stamp. Wondering why use old z80 tech in today’s world? Need to re-create a legacy design for code preservation reasons or support, just curious since I enjoy looking at your skills 🙂
I see it’s a new design by your date stamp. Wondering why use old z80 tech in today’s world? Need to re-create a legacy design for code preservation reasons or support, just curious since I enjoy looking at your skills 🙂
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Amazing, a Z80, a 6545 for video, some hitachi sram 62256 ?, maybe a 8255 and a BASIC Rom… so much memories.
One question, why so many TTL glue logic ? There are more than the few ones required to operate the chip listed above.
Are they more chips under the keyboard ?
Could you tell us more about this very neat board ?
One question, why so many TTL glue logic ? There are more than the few ones required to operate the chip listed above.
Are they more chips under the keyboard ?
Could you tell us more about this very neat board ?
Scope, soldering iron, multimeter and signal generator.
About 5 boxes of components.
2 racks of component drawers.
Despite some of the components being in mixed boxes I know where 99% of components are.
Organisation from chaos.
About 5 boxes of components.
2 racks of component drawers.
Despite some of the components being in mixed boxes I know where 99% of components are.
Organisation from chaos.
I still long for the old Z80.
Great instruction set.
I wrote the software for a Teletext adapter in 1983 for the Sinclair Spectrum.
Many lines of code due to Spectrum's odd screen memory layout.
Managed to get Teletext 40 characters/line into a 32 characters/line screen by bit rotating.
Worked well in the end.