Weather related scope faults?

[Diabolical Artificer]

Today in the workshop I turned my Tektronix 585A on to monitor an oscillator on the bench, no sweep, odd. I then tried my Tek 545B, turned it on, no sweep, odder & odder, both were working fine yesterday.

As you all know we've had a prolonged cold spell recently, today the weather is a lot warmer. I noticed all my cables felt "greasy" to the touch, high humidity?

The only explantion for both Tek 500 series scopes going gaga is high humidity and the possibility that some valves in the scopes have died: my workshop is essentially a lean to on the house, no heating, I've noticed valves in scopes stored in sheds have gone to air, possibly caused by thermal expansion & contraction due to the cold.

Has anyone had similar test gear issues recently?

Andy.

[G.Castle]

Damp and condensation is the big killer of oscilloscopes particularly the eht overwindings on mains transformers, though tracking in other parts of the circuitry can cause temporary failures too.

Greg.

[Bazz4CQJ]

I think that the RH of the new warm air that has come in is much higher than we've had for the last week or two and lots of workshops are seeing real problems with condensation.

B

[Lloyd 1985]

Not had a problem recently, but a good few years back, when I had my old workshop in a row of garages at the top of the garden, it got down below freezing in the workshop, and I fired up one of my old dual standard Bush TV’s and the lop valve cracked after I turned the set off! I decided it’d be better to not fire up any other sets after that until it had warmed up in there a bit.

Regards
Lloyd

[Tim]

I keep my “ best” scopes and the AVO VCM in what used to be our airing cupboard. It’s nice and dry in there. Also good for storing welding rods.

[The Philpott]

Was expecting this- the 'soaking wet bench vice phenomenon'. Had to leave workshop door open for several hours, and two fans running to get some turbulence going.
(My welding rods are also indoors)

One part of the south-east had a 22C rise in 24 hours..

Dave

[Vintage_RC]

A while back I brought a PC monitor down from the very cold loft into the warm house and turned it on. Result - lots of crackling and other nasty sounds and smells and one dead monitor. I should have left it to acclimatise to the house temperature for several hours.

[David Simpson]

Andy, back before Covid, I remember a very long intensive thread about shed insulation, heating & ventilation(perhaps a Mod could give a reference, please ?). In which myself & several others banged-on(& on) about Dew-Point, "U" value", and other contributory factors relating to what you are experiencing.
Basically, outside sheds, lean-to's, lofts, etc., used as radio/electronics workshops - need to have the same environmental conditions as a "not too warm" well ventilated spare bedroom.
A cold damp outside shed, perhaps coupled with poor safety switchgear & earthing, is a recipe for permanent damage to equipment & the safety of the user.
Regards, David

[Nickthedentist]

Get a cheap humidity meter off eBay or Amazon.

A dehumidifer is a worthwhile investment, but note that the normal sort only work if the background temperature is a few degrees above freezing (I think).

[G6Tanuki]

The recent cold followed by warming has caused unwelcome condensation in all sorts of places; the insulator at the outer end of my longwire antenna [which is a high-voltage point] did a bit of a flashover when I squirted 200 Watts of carrier up it!

Dry is good. I've always got a dehumidifier running [on the humidistat] in my office/radio-room. Damp can even cause issues in printers, where the electrostatic charge used to attract the tomer to the drum can leak away....

[ms660]

We got the full brunt of that southerly warm air flow, earlier on in that day in the early hours of the morning we had a dash of freezing rain then later on in the day the heavily moisture laden warm air coming in from the sea, the outside surfaces of the windows and doors were dripping with condensation, the surface of the wooden bench which is outside under cover was also soaking wet.

The electrical stuff seems to have survived so far.

Only known it as bad as that once before at this location.

Lawrence.

[HamishBoxer]

The excess cold could show up a few out of spec caps etc?

[G6fylneil]

This morning I took my Fluke 79IV meter out of my car boot, where it has been for three weeks, and took it into the house. I switched it on and it started beeping furiously, I've had it for 20 years, but I didn't know it had a condensation sensor! I took the batteries out and left it in the airing cupboard, and it's happy now.

[Diabolical Artificer]

Interesting posts, yep, I know my workshop isn't ideal, baking hot in summer, freezing in winter but so far I've never had a problem, the day in question was really unusual, in the minusus for weeks followed by rain and a relative warm spell.

Finance precludes a heater or humidifier I don't even have heating in my bedroom, got to keep the bills down.

I'll open up the scopes and see what the craic is, theyre the only test gear so far playing up.

Andy.

[Reelman]

Shortly after I joined the IT department in February 1987 we had a delivery of a Tandem NonStop mainframe valued at £3.5M. This arrived after a long cold journey in an artic with just the driver. Straight off the wagon and into the computer room via the loading bay. Mainframes did not come in boxes but in various sized “wardrobes” on castors, sometimes with just a piece of clear plastic wrapping. We nearly lost one off the end of the loading bay due to a slight slope. Amused us all that such valuable kit would be entrusted to just one man. The Eastern Block would have paid very good money to obtain one….

Anyway, the installation dept where I worked was keen to get it up and running as it was the first we had seen and the commissioning team were already on site. Being the new boy I didn’t want to spoil their fun but it hadn’t occurred to anyone else that there was condensation on the kit until I wiped some down and showed them the wet paper towel.
My suggestion that we leave it all to acclimatise overnight was accepted.

Peter

[Bufo Bill]

Originally Posted by HamishBoxer

The excess cold could show up a few out of spec caps etc?

Yes, most definitely the case here. Spent a therapeutic afternoon testing and replacing caps in my HP1825A plug-in.
Cheers from Bill.