Type 13A 'scope, full brightness on lamp limiter!

[Craig Sawyers]

Age 15 I hoiked the 13A up a flight of stone steps, and put it on a bench in our porch.

Over half a century later, there is 100% of no way I could do this now. And heavier gear/boatanchors that 10 years ago were no problem for me, I need to rope in the assistance of my long-suffering wife.

Craig

[Cobaltblue]

Can we stay on topic please.

Further off topic posts will just be deleted.

Cheers

Mike T

[Diabolical Artificer]

With any old scope especially one of this age before powering it up I'd inspect it minutely looking for obvious burnt components, physically leaky caps, gone to air valves, wires off etc. I'd then check the mains fuse, test the power tfmr for shorts, test each electrolytic for leakage current, reform or change. I'd then re-seat every valve by jiggling it about a bit. Check all pots & switch's/clean, giving them a good jiggle back & forth.

While I doing all this I'd check a schematic/manuel so I have an idea of the power supply, EHT supply & potential divider that feeds the CRT. Check that too.

Only after all this would I power it up on a variac & LL whilst chucking every meter I have at the power supply to check all the rails whilst powering it up.

Andy.

[buggies]

If you don't still have a stock of 100W bulbs then wire a second holder in parallel with the first and use two 60s?

[Craig Sawyers]

Regarding the OP's budget for a Variac, it takes time and lurking on auction sites (not just the obvious eBay), but there are bargains to be had out there. Most I've paid was £60 for a boxed 5A one with meters.

Craig

[GMB]

Originally Posted by Craig Sawyers

Amazing that the hernia inducing Hartley 13A is still there. When they were available pretty much new when released by the Ministry back in the late 60's to early 70's this was my first ever oscilloscope

Mine too! I bought mine from Smiths in Lisle Street and planned to take it home on tube and train - but after about 5 yards I realised I was in trouble. Rescued by my dad in a taxi!

Originally Posted by Craig Sawyers

The thing that is in its favour is that the CRT is true dual gun.

Sorry to dissapoint but it isn't dual gun. It uses a beam splitter at the Y plates - which is why there is more cross-talk than you might like.

The 13A has a huge switch-on surge which is why you must fit anti-surge fuses or they just go bang. (Rather like big torroids like variacs.) Not sure how lamp-limiter gets on with that - but badly I suspect.