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Hello Dave I have been skipping over this thread, assuming that it concerned dealing with "ground bounce" on MSI logic chips on a buss. It’s a synchronous logic thing from the days of 54/74 TTL

i noticed this last night. the show is about 3 yrs old so maybe it has already been posted. https://www.pbs.org/video/nova-wonders-whats-the-universe-made-of-2eyoyw/ 30:37 in Peter Fisher's lab at MIT

Dave, I visited Smith-Kettlewell Eye Research Institute in SF around 1974 for some collaborative work.? Google maps shows them about 2.5 miles from the Sutro Tower that is your RF ground noise

Thanks everyone for their inputs. Keep the stories coming. They're great! I was pretty punchy last night and probably wasn't saying what I was trying to very well. I think what was throwing me was the

Back in my early teens we lived on s slight hill and could see the State Police tower red lights on another hill 2-3 miles and could hear them on my homemade crystal radio and they were on 30

Bonjour, sealed reed relays are VERY reliable and the telephone system had lifetimes for 40 years in constant use on 24.48V. But reeds can develop film on the contact surfaces, especially if unused

Just generally (perhaps not specifically for calibrating verticals) you can move to smaller but cheaper (if not as accurate, and as low a noise floor) like the TinySA, NanoVNA, et. al. They also

In my teens I live 10km from the CBK transmitter: 540KHz 50KW clear channel omnidirecional... I had an end fed antenna in the back yard of no more than 30m in length. I built a cheap Heathkit GR64

Hi Eric, Just a thought here - you said: “I am having issues with 60, 20 and 6. With them also causing some havoc on auto range as well. When I have a situation where they are working the unit locks

Pulled the tube last night and found a rice grain sized piece of glass and a smaller bit of metal rattling around inside. I assume ANY loose bits in a tube is a bad sign? Also, it looks like the tube

I was able to use an FM radio, probe, and Internet streaming to identify FM stations on noise. No need for a spectrum analyser... even though we have them. -- Roy Thistle

Dave Tell your kids that the wifi will be off at a certain time and be off for xx minutes, ?they will not die, you are the boss. Leon Robinson ?K5JLR

Dave, As others have replied, no doubt FM broadcast from the Sutro Tower. Unreliable sources (Wikipaedia) indicate there are at least 4 FM broadcast stations 96.5 to 104.5 MHz transmitting from there.

You who replied to this are amazing! If you want to see more photographs of difficult-to-identify scopes (and very early ultrasound devices - including the famous one made from a B-29 ball turret)

There are no rocker switches on a 547.

Both versions (the one spotted by Siggi and the one currently listed) seem to be 1AD3001-0S for 16-22 V compared to 1AD3001-0A, version for 10-15 V; otherwise hard to spot a difference. TT

First, I see something very similar on my 475s here on the opposite coast. I do live just north of Washington DC with a clear view of "Broadcast Hill" in Tenleytown to the south, and (until they were

Hi! The ALT-Mode didn't work correctly on my first 7854. Initially it wasn't complicated to find the error - a diode installed the wrong way. But I couldn't beleave that this mistake wasn't found at

I have a TinySA on the way in the mail. That's exactly what I'm going to do! Dave

While rebuilding my 2235 Scope, I found one wire for the Variable Holdoff pot wasn't soldered, wire was in the hole in the lug, but someone forgot to poke it with the hot end of a soldering iron. I