Selenium is one of those micro nutrients that you do need. However, it is also toxic if you get too much. Overheated selenium rectifiers can produce selenium dioxide which can be toxic if too much is

I am a high myope (correction near -10 diopters) and have been for years. I started developing cataracts (I just turned 70 in 2020) probably about 25 years ago. I just had cataract surgery this past O

I thought so. I know they made sensors of various kinds with them. I found one of the computer memory ones at a hamfest and I did not buy it (I should have). Steve yahoo.com@groups.io> wrote:

A question for the group. Does anyone know what the smallest CRT made (in more than a single curiosity or lab item) is? I think I have a candidate. I will take a photo of it the next time I can get to

Did any company use magnetostrictive delay lines in scopes or was the early use for computer memory? Steve Horii

Another tiny scope - an RF surveillance receiver made by F.G. Mason used a small CRT as a spectrum display. The model with the tiny CRT is the Mini Probe Receiver. Details are here in the Crypto Museu

Tiny scope thread - I have a NIM (nuclear instrumentation module) that is an oscilloscope that goes in a NIM bin for power. It uses some small Lemo coax connectors for the inputs. Unfortunately not wo

I purchased a set of left-hand drill bits made by Drill Hog ( https://drillhog.com/). They sell both through eBay and Amazon. From them directly, you can also purchase single bits. They are made in th

I have not seen Torx screws on the older Tek equipment, so I looked it up. Torx screws were apparently invented in 1967 but not patented until 1971. I found this for history buffs: https://www.hausoft

Before digital storage, CRTs with P7 (or other long-persistence phosphor) were used for physiological monitoring. The early patient monitors in ICUs and ORs had these CRTs. The reason was that with th

Oops! My bad. Momentary dyslexia or something like that. I misread the original message as 2336 instead of 2236. It is a 2336-YA manual that I found on eBay. Sorry for the mistake. Steve H

I managed to find a printed copy of this manual. I was surprised at its size - it is at least two inches thick. It is thicker than the service manual for the 7L5 spectrum analyzer. The 2336 brochure (

We have been severely affected by the postal slowdown. As has been noted, PA has had it’s share of workers out because of COVID-19 either infected or in quarantine. It is not that USPS is not trying -

Dennis, My Zip code is 19010 and the book was not in today's mail. Pennsylvania seems to have been hard hit by the USPS slowdown. A package I sent using USPS Priority Mail 2-day took over two weeks to

If the heat gun can melt epoxy resins, it may be hot enough to melt other plastics - like the insulation on wires (unless it's Teflon or silicone - which it may be in an HV supply). There are quite a

I am sure you in the US are aware and may have experienced this with mailing packages and letters for the holidays, but US mail has been considerably delayed, though it has gotten somewhat better in t

We had a 1000-foot spool. Thankfully, the label specified that it was a single cable with no breaks. RG-59 I think. I do not recall what the prop delay was, but it was sort of measurable. I recall we

One thing my engineer buddy did in the lab we used was to look at the “speed of light”. He took a reel of coax we had gotten to run some Ethernet links. This was before twisted pair took over from coa

I did not think this belonged in any of the current threads. Besides Tek scopes, I also restore and mess about with time and frequency stuff. I use mostly quartz frequency standards and my favorites a

Just a quick note on Siglent stuff. I bought a Siglent signal generator - a 2042X. It has all the standard waveforms plus arbitrary waveform capability. It has a touch screen so you could actually jus