Entropy

Relax in southern comfort on the east bank of the Mississippi. You're just around the corner from Beale Street and Sun Records. Watch the ducks, throw back a few and tell us what's on your mind.
Gold
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Re: Entropy

Post by Gold » Sat Oct 06, 2018 12:44 pm

My semi retired 8060A moved to the mountains. I got many good years from that meter but it is now missing buttons. I also like the gain ranging of the Fluke 179. It does dB and is very accurate.

I got an 8050A eBay special that promptly died. I didn’t know if it was the display or the unit. The battery was also dodgy. Before I fixed the crossed live and neutral in the shop power I had to use floating meters because I didn’t know what was going on. Now I guess a grounded meter is okay. I think I tossed it in frustration though.

I got a pair of HP 400GL’s as part of the Shure lathe package. They are in a rack frame with a center mounted connector panel. This interfaces with a beautifully built active meter panel with Daven attenuators. Also dead. I was looking around the web last night and an antique radio and test equipment guy suggested leaving them on for a week to let the electrolytic and wet tantalum capacitors reform. He said they are high quality and not to sub modern parts for them as performance will suffer. I’ll give it a shot and hope for a smokeless week.

Edit: the Fluke 179 doesn’t have a dB mode but the 287 does. When I use the 179 to calibrate I only do 1K at +4 dBu. I don’t mind a voltage readout for that. The Agilent 1252 does dB if I need it. They agree on readings.

Gold
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Re: Entropy

Post by Gold » Tue Oct 09, 2018 4:35 pm

I think something good is happening with the HP400GL’s. They have been on for three days now. When I turn the knob things are acting differently than they were a few days ago. The one that showed no movement with input signal had the needle stuck at about 10% deflection. After a day or so the needle went to the rest position. When I turned the knob it would stick again at 10% deflection and take a while to get to rest. It is now getting back to rest faster. The other one showed input but went bonkers when turning the knob. It’s calming down a little. Fingers crossed.

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mediatechnology
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Re: Entropy

Post by mediatechnology » Tue Oct 09, 2018 6:00 pm

My HP400FL also does the same thing. It likes being on.

The 8060 will appear to "die" with no LCD display activity if the internal NiCds can't be charged - even when the AC power is on.

If it had a good LCD display you may have tossed a good meter.

Gold
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Re: Entropy

Post by Gold » Tue Oct 16, 2018 7:27 pm

One of the HP 400GL's has come back to life. It needs a little calibration but is behaving nicely. The other one, not so much. I'm going to leave it on because things are still changing. The meter is getting "stuck" in a different position as time goes by. The behavior when changing the range is also different than it was and keeps changing.

The Fluke 287 came back. It works! I sent it with out batteries and it came back with batteries. I made money on the deal!

I got my new test bench setup together. I'm pleased with how it came out. There is some more to do but for the most part it's done.

Before:
Bench_Old.jpg
After:
Bench_New.jpg
I have a Sony CDP-500 CD player that is going in the open top spot.
1/4" bolts work great as tool and cable holders. They can slide around wherever they are needed and are easy to change around. As my need change this setup should be able to keep up.
Bench_New-2a.jpg
Bench_New-3.jpg
Bench_New-4.jpg
Bench_New-5.jpg

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mediatechnology
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Re: Entropy

Post by mediatechnology » Fri Oct 19, 2018 7:40 am

Paul your bench looks very organized.
I'd leave the HP on continuously.
I have several and they all do the same thing until the caps reform.

I've been on a test equipment and gizmo repair binge too.
It's been raining for almost two weeks now so thats gotten me out of the yard and into the shop and garage.

I inherited an old DigiMax D-1200 frequency counter from a radio station years ago and the sensitivity, at audio frequencies, had degraded.
While it took several volts at 1 kHz to get a stable reading, 100 kHz only required tens of millivolts.
I recapped it and it came back to life.

My monitoring cables had become intermittent so I tested and replaced all the bad ones.
Used a Neutrick jack board to switch them to 1/4" TRS female rather than having loose male cable ends hanging around.
The monitor return loop is now half-normal'd.

I went through my LED drawer and threw out all the 2nd and 3rd generation ones.
I figured if they weren't bright at 5 mA I didn't need them.
I keep the vintage ones with gold leads - I've got a pile of gold components to photograph.

For years I've used the same small pile of 2N3904/2N3906 transistors for prototyping.
I decided to check them - some had gains as low as 35.
Time for the trash and a restock from the fresh parts bin.

After moving a bunch of crap piled up on the bench I "discovered" a new window behind it.
There's a view of the street and my neighbor's house I had forgotten about.

Swapped the hours and seconds display in the Heathkit GC-1092 clock and disabled the dimmer photocell.
Hope to burn the cathode crud off the SP-352 display.
Those suckers are $50 each now.

Also restored an old ancient MM5314 LED clock.
I had to scrounge to find displays for this particular PC board - some of the segments were out.
The 7 segment LEDs I had had been de-soldered so I must have been scrounging for displays when I built it as a teenager.

I'm sure I've forgotten a few projects in the last week but most involve changing batteries or capacitors or throwing bad stuff out.

My next project is to restore a "Nixie" clock I built out of RTL logic when I was 12.
This one uses Amperex ZM-1000 tubes which have been dark for 40 years so they should be OK.

Gold
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Re: Entropy

Post by Gold » Fri Oct 19, 2018 9:03 am

That’s a good pile of stuff out of the way. A common dream for residents of NYC is to discover a forgotten room. A window is close.

The working HP400GL appears to have been custom calibrated. The top of the scale on the meter is “0”.On the 0dB gain position +4dBm reads 0 and 0dBm reads -4 on the meter scale. That’s too much of a coincidence to be accidental.

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mediatechnology
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Monday Is Attenuator Cleaning Day

Post by mediatechnology » Tue Oct 23, 2018 12:14 pm

I guess I'm in the "mood" to fix all those daily annoyances on the test bench.
Yesterday was "attenuator" day.
The 'scope's A channel had gotten intermittent and fortunately it wasn't the part of the switch that is shielded.

I also cleaned the Heatkit IG-18 output level pot and attenuator.
Both it and the 'scope were driving me batty.

Later in the day I pulled out the Heathkit IM-5238 AC Voltmeter.
That repair proved to be interesting and became the genesis for a new sub-forum: https://www.proaudiodesignforum.com/for ... =16&t=1014

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JR.
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Re: Entropy

Post by JR. » Mon Oct 29, 2018 4:01 pm

mediatechnology wrote:
Thu Oct 04, 2018 11:07 am
I've found a slurry if baking soda works pretty good at drawing out fire ant toxin.
You have to let it dry so it pulls. Kinda like K2R spot remover on stains.
Have I told you'all how much I hate fire ants... :x

I have been having good success at banishing them from my yard with a two part strategy but I guess the success made me a little lax... Today I was testing out my new 20' window washing pole, trying to clean the sap that was weeping onto the back corner of my pretty new (was) shiny roof. I wasn't paying close attention to the entire 20' of pole and inadvertently laid the handle in the middle of a hot fire ant pile. I figured something was wrong when I picked up the pole over my head and felt bites on my hand and ants dropping onto my head from the pole held above me. :o :o

I tried the baking soda remedy but admit I didn't leave the slurry on my hands to completely dry (I still had a hose running outside). I got one or maybe two bites on my face.. one near the temple I can see. When I went into my bathroom to apply the baking soda I saw a couple dead ants on my face, and two still alive ones crawling around on my t-shirt. I think I may have a bite on the side of my nose by my eye, but I'm not going to baking soda that close to my eye.

My fingers are already swelling up so perhaps not enough... It usually takes a few days for ant bites/stings to run their course.

I really HATE fire ants. :x :x :x

JR

PS: I'll revisit cleaning the roof tomorrow. :lol:

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JR.
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Re: Entropy

Post by JR. » Tue Oct 30, 2018 11:54 am

update... this morning the pustules are formed and my right hand feels like a claw... I count 10 bites/stings on that one hand alone, left hand only has 3 or 4, not to mention 2 bites on my face. One on my temple, and another on my eyelid... I wonder what an ant bite on the eyeball would feel like?

The baking soda did not appear to do much but a bunch of the bite locations were not obvious until a day later, so probably didn't apply enough, long enough.

I had good success with calamine and bandaids last time, almost too many bites to do that to now.

Good news is the swelling has probably peaked so should subside from here. 8-)

JR

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mediatechnology
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Re: Entropy

Post by mediatechnology » Tue Oct 30, 2018 2:34 pm

Aspirin? Benadryl?

I'm constantly worried about picking up fire ants on a garden hose or extension cord.

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